diff --git a/common/src/main/java/io/druid/math/expr/Evals.java b/common/src/main/java/io/druid/math/expr/Evals.java index 702037309a91..1ff14385738b 100644 --- a/common/src/main/java/io/druid/math/expr/Evals.java +++ b/common/src/main/java/io/druid/math/expr/Evals.java @@ -20,7 +20,6 @@ package io.druid.math.expr; import com.google.common.base.Strings; -import io.druid.common.guava.GuavaUtils; import io.druid.java.util.common.logger.Logger; import java.util.Arrays; @@ -32,27 +31,6 @@ public class Evals { private static final Logger log = new Logger(Evals.class); - public static Number toNumber(Object value) - { - if (value == null) { - return 0L; - } - if (value instanceof Number) { - return (Number) value; - } - String stringValue = String.valueOf(value); - Long longValue = GuavaUtils.tryParseLong(stringValue); - if (longValue == null) { - return Double.valueOf(stringValue); - } - return longValue; - } - - public static boolean isConstant(Expr expr) - { - return expr instanceof ConstantExpr; - } - public static boolean isAllConstants(Expr... exprs) { return isAllConstants(Arrays.asList(exprs)); diff --git a/extensions-contrib/virtual-columns/src/main/java/io/druid/segment/MapVirtualColumn.java b/extensions-contrib/virtual-columns/src/main/java/io/druid/segment/MapVirtualColumn.java index 75fe13ad6c82..7fc360ba7437 100644 --- a/extensions-contrib/virtual-columns/src/main/java/io/druid/segment/MapVirtualColumn.java +++ b/extensions-contrib/virtual-columns/src/main/java/io/druid/segment/MapVirtualColumn.java @@ -22,21 +22,24 @@ import com.fasterxml.jackson.annotation.JsonCreator; import com.fasterxml.jackson.annotation.JsonProperty; import com.google.common.base.Preconditions; +import com.google.common.collect.ImmutableList; import com.google.common.collect.Maps; import com.metamx.common.StringUtils; import io.druid.query.dimension.DefaultDimensionSpec; +import io.druid.query.dimension.DimensionSpec; import io.druid.query.filter.DimFilterUtils; +import io.druid.segment.column.ValueType; import io.druid.segment.data.IndexedInts; +import io.druid.segment.virtual.VirtualColumnCacheHelper; import java.nio.ByteBuffer; +import java.util.List; import java.util.Map; /** */ public class MapVirtualColumn implements VirtualColumn { - private static final byte VC_TYPE_ID = 0x00; - private final String outputName; private final String keyDimension; private final String valueDimension; @@ -58,13 +61,14 @@ public MapVirtualColumn( } @Override - public ObjectColumnSelector init(String dimension, ColumnSelectorFactory factory) + public ObjectColumnSelector makeObjectColumnSelector(String dimension, ColumnSelectorFactory factory) { final DimensionSelector keySelector = factory.makeDimensionSelector(DefaultDimensionSpec.of(keyDimension)); final DimensionSelector valueSelector = factory.makeDimensionSelector(DefaultDimensionSpec.of(valueDimension)); - int index = dimension.indexOf('.'); - if (index < 0) { + final String subColumnName = VirtualColumns.splitColumnName(dimension).rhs; + + if (subColumnName == null) { return new ObjectColumnSelector() { @Override @@ -94,7 +98,7 @@ public Map get() }; } - final int keyId = keySelector.lookupId(dimension.substring(index + 1)); + final int keyId = keySelector.lookupId(subColumnName); return new ObjectColumnSelector() { @@ -123,6 +127,37 @@ public String get() }; } + @Override + public DimensionSelector makeDimensionSelector(DimensionSpec dimensionSpec, ColumnSelectorFactory factory) + { + // Could probably do something useful here if the column name is dot-style. But for now just return nothing. + return null; + } + + @Override + public FloatColumnSelector makeFloatColumnSelector(String columnName, ColumnSelectorFactory factory) + { + return null; + } + + @Override + public LongColumnSelector makeLongColumnSelector(String columnName, ColumnSelectorFactory factory) + { + return null; + } + + @Override + public ValueType nativeType(String columnName) + { + return columnName.indexOf('.') < 0 ? ValueType.COMPLEX : ValueType.STRING; + } + + @Override + public List requiredColumns() + { + return ImmutableList.of(keyDimension, valueDimension); + } + @Override public boolean usesDotNotation() { @@ -137,7 +172,7 @@ public byte[] getCacheKey() byte[] output = StringUtils.toUtf8(outputName); return ByteBuffer.allocate(3 + key.length + value.length + output.length) - .put(VC_TYPE_ID) + .put(VirtualColumnCacheHelper.CACHE_TYPE_ID_MAP) .put(key).put(DimFilterUtils.STRING_SEPARATOR) .put(value).put(DimFilterUtils.STRING_SEPARATOR) .put(output) diff --git a/indexing-hadoop/src/main/java/io/druid/indexer/InputRowSerde.java b/indexing-hadoop/src/main/java/io/druid/indexer/InputRowSerde.java index 4ef717dacd4f..937c0db262db 100644 --- a/indexing-hadoop/src/main/java/io/druid/indexer/InputRowSerde.java +++ b/indexing-hadoop/src/main/java/io/druid/indexer/InputRowSerde.java @@ -36,6 +36,7 @@ import io.druid.segment.incremental.IncrementalIndex; import io.druid.segment.serde.ComplexMetricSerde; import io.druid.segment.serde.ComplexMetrics; +import io.druid.segment.VirtualColumns; import org.apache.hadoop.io.ArrayWritable; import org.apache.hadoop.io.Text; import org.apache.hadoop.io.WritableUtils; @@ -87,10 +88,10 @@ public InputRow get() Aggregator agg = aggFactory.factorize( IncrementalIndex.makeColumnSelectorFactory( + VirtualColumns.EMPTY, aggFactory, supplier, - true, - null + true ) ); try { diff --git a/processing/src/main/java/io/druid/query/Druids.java b/processing/src/main/java/io/druid/query/Druids.java index dfa7d238fb50..e37e8ebcae40 100644 --- a/processing/src/main/java/io/druid/query/Druids.java +++ b/processing/src/main/java/io/druid/query/Druids.java @@ -55,6 +55,7 @@ import io.druid.query.timeboundary.TimeBoundaryResultValue; import io.druid.query.timeseries.TimeseriesQuery; import io.druid.segment.VirtualColumn; +import io.druid.segment.VirtualColumns; import org.joda.time.DateTime; import org.joda.time.Interval; @@ -330,18 +331,20 @@ public static class TimeseriesQueryBuilder { private DataSource dataSource; private QuerySegmentSpec querySegmentSpec; + private boolean descending; + private VirtualColumns virtualColumns; private DimFilter dimFilter; private QueryGranularity granularity; private List aggregatorSpecs; private List postAggregatorSpecs; private Map context; - private boolean descending; - private TimeseriesQueryBuilder() { dataSource = null; querySegmentSpec = null; + descending = false; + virtualColumns = null; dimFilter = null; granularity = QueryGranularities.ALL; aggregatorSpecs = Lists.newArrayList(); @@ -355,6 +358,7 @@ public TimeseriesQuery build() dataSource, querySegmentSpec, descending, + virtualColumns, dimFilter, granularity, aggregatorSpecs, @@ -459,6 +463,22 @@ public TimeseriesQueryBuilder intervals(List l) return this; } + public TimeseriesQueryBuilder virtualColumns(VirtualColumns virtualColumns) + { + this.virtualColumns = virtualColumns; + return this; + } + + public TimeseriesQueryBuilder virtualColumns(List virtualColumns) + { + return virtualColumns(VirtualColumns.create(virtualColumns)); + } + + public TimeseriesQueryBuilder virtualColumns(VirtualColumn... virtualColumns) + { + return virtualColumns(VirtualColumns.create(Arrays.asList(virtualColumns))); + } + public TimeseriesQueryBuilder filters(String dimensionName, String value) { dimFilter = new SelectorDimFilter(dimensionName, value, null); @@ -1104,7 +1124,7 @@ public static class SelectQueryBuilder private QueryGranularity granularity; private List dimensions; private List metrics; - private List virtualColumns; + private VirtualColumns virtualColumns; private PagingSpec pagingSpec; public SelectQueryBuilder() @@ -1233,12 +1253,22 @@ public SelectQueryBuilder metrics(List m) return this; } - public SelectQueryBuilder virtualColumns(List vcs) + public SelectQueryBuilder virtualColumns(VirtualColumns vcs) { virtualColumns = vcs; return this; } + public SelectQueryBuilder virtualColumns(List vcs) + { + return virtualColumns(VirtualColumns.create(vcs)); + } + + public SelectQueryBuilder virtualColumns(VirtualColumn... vcs) + { + return virtualColumns(VirtualColumns.create(Arrays.asList(vcs))); + } + public SelectQueryBuilder pagingSpec(PagingSpec p) { pagingSpec = p; diff --git a/processing/src/main/java/io/druid/query/aggregation/AggregatorUtil.java b/processing/src/main/java/io/druid/query/aggregation/AggregatorUtil.java index e106ef828c59..f16ddcce38ac 100644 --- a/processing/src/main/java/io/druid/query/aggregation/AggregatorUtil.java +++ b/processing/src/main/java/io/druid/query/aggregation/AggregatorUtil.java @@ -20,10 +20,6 @@ package io.druid.query.aggregation; import com.google.common.collect.Lists; -import io.druid.segment.ColumnSelectorFactory; -import io.druid.segment.FloatColumnSelector; -import io.druid.segment.LongColumnSelector; -import io.druid.segment.NumericColumnSelector; import io.druid.java.util.common.Pair; import java.util.HashSet; @@ -88,54 +84,4 @@ public static Pair, List> condensedAggre } return new Pair(condensedAggs, condensedPostAggs); } - - public static FloatColumnSelector getFloatColumnSelector( - final ColumnSelectorFactory metricFactory, - final String fieldName, - final String fieldExpression, - final float nullValue - ) - { - if (fieldName != null && fieldExpression == null) { - return metricFactory.makeFloatColumnSelector(fieldName); - } - if (fieldName == null && fieldExpression != null) { - final NumericColumnSelector numeric = metricFactory.makeMathExpressionSelector(fieldExpression); - return new FloatColumnSelector() - { - @Override - public float get() - { - final Number number = numeric.get(); - return number == null ? nullValue : number.floatValue(); - } - }; - } - throw new IllegalArgumentException("Must have a valid, non-null fieldName or expression"); - } - - public static LongColumnSelector getLongColumnSelector( - final ColumnSelectorFactory metricFactory, - final String fieldName, - final String fieldExpression, - final long nullValue - ) - { - if (fieldName != null && fieldExpression == null) { - return metricFactory.makeLongColumnSelector(fieldName); - } - if (fieldName == null && fieldExpression != null) { - final NumericColumnSelector numeric = metricFactory.makeMathExpressionSelector(fieldExpression); - return new LongColumnSelector() - { - @Override - public long get() - { - final Number number = numeric.get(); - return number == null ? nullValue : number.longValue(); - } - }; - } - throw new IllegalArgumentException("Must have a valid, non-null fieldName or expression"); - } } diff --git a/processing/src/main/java/io/druid/query/aggregation/DoubleMaxAggregatorFactory.java b/processing/src/main/java/io/druid/query/aggregation/DoubleMaxAggregatorFactory.java index 36c3073e2a1c..871f0fe8a16e 100644 --- a/processing/src/main/java/io/druid/query/aggregation/DoubleMaxAggregatorFactory.java +++ b/processing/src/main/java/io/druid/query/aggregation/DoubleMaxAggregatorFactory.java @@ -22,11 +22,10 @@ import com.fasterxml.jackson.annotation.JsonCreator; import com.fasterxml.jackson.annotation.JsonProperty; import com.google.common.base.Preconditions; +import com.google.common.collect.ImmutableList; import com.google.common.primitives.Doubles; import io.druid.common.utils.StringUtils; -import io.druid.math.expr.Parser; import io.druid.segment.ColumnSelectorFactory; -import io.druid.segment.FloatColumnSelector; import java.nio.ByteBuffer; import java.util.Arrays; @@ -42,46 +41,30 @@ public class DoubleMaxAggregatorFactory extends AggregatorFactory private final String name; private final String fieldName; - private final String expression; @JsonCreator public DoubleMaxAggregatorFactory( @JsonProperty("name") String name, - @JsonProperty("fieldName") final String fieldName, - @JsonProperty("expression") String expression + @JsonProperty("fieldName") final String fieldName ) { Preconditions.checkNotNull(name, "Must have a valid, non-null aggregator name"); - Preconditions.checkArgument( - fieldName == null ^ expression == null, - "Must have a valid, non-null fieldName or expression" - ); + Preconditions.checkNotNull(fieldName, "Must have a valid, non-null fieldName"); this.name = name; this.fieldName = fieldName; - this.expression = expression; - } - - public DoubleMaxAggregatorFactory(String name, String fieldName) - { - this(name, fieldName, null); } @Override public Aggregator factorize(ColumnSelectorFactory metricFactory) { - return new DoubleMaxAggregator(getFloatColumnSelector(metricFactory)); + return new DoubleMaxAggregator(metricFactory.makeFloatColumnSelector(fieldName)); } @Override public BufferAggregator factorizeBuffered(ColumnSelectorFactory metricFactory) { - return new DoubleMaxBufferAggregator(getFloatColumnSelector(metricFactory)); - } - - private FloatColumnSelector getFloatColumnSelector(ColumnSelectorFactory metricFactory) - { - return AggregatorUtil.getFloatColumnSelector(metricFactory, fieldName, expression, Float.MIN_VALUE); + return new DoubleMaxBufferAggregator(metricFactory.makeFloatColumnSelector(fieldName)); } @Override @@ -99,7 +82,7 @@ public Object combine(Object lhs, Object rhs) @Override public AggregatorFactory getCombiningFactory() { - return new DoubleMaxAggregatorFactory(name, name, null); + return new DoubleMaxAggregatorFactory(name, name); } @Override @@ -115,7 +98,7 @@ public AggregatorFactory getMergingFactory(AggregatorFactory other) throws Aggre @Override public List getRequiredColumns() { - return Arrays.asList(new DoubleMaxAggregatorFactory(fieldName, fieldName, expression)); + return Arrays.asList(new DoubleMaxAggregatorFactory(fieldName, fieldName)); } @Override @@ -140,12 +123,6 @@ public String getFieldName() return fieldName; } - @JsonProperty - public String getExpression() - { - return expression; - } - @Override @JsonProperty public String getName() @@ -156,20 +133,17 @@ public String getName() @Override public List requiredFields() { - return fieldName != null ? Arrays.asList(fieldName) : Parser.findRequiredBindings(expression); + return ImmutableList.of(fieldName); } @Override public byte[] getCacheKey() { byte[] fieldNameBytes = StringUtils.toUtf8WithNullToEmpty(fieldName); - byte[] expressionBytes = StringUtils.toUtf8WithNullToEmpty(expression); - return ByteBuffer.allocate(2 + fieldNameBytes.length + expressionBytes.length) + return ByteBuffer.allocate(1 + fieldNameBytes.length) .put(CACHE_TYPE_ID) .put(fieldNameBytes) - .put(AggregatorUtil.STRING_SEPARATOR) - .put(expressionBytes) .array(); } @@ -190,7 +164,6 @@ public String toString() { return "DoubleMaxAggregatorFactory{" + "fieldName='" + fieldName + '\'' + - ", expression='" + expression + '\'' + ", name='" + name + '\'' + '}'; } @@ -210,9 +183,6 @@ public boolean equals(Object o) if (!Objects.equals(fieldName, that.fieldName)) { return false; } - if (!Objects.equals(expression, that.expression)) { - return false; - } if (!Objects.equals(name, that.name)) { return false; } @@ -224,7 +194,6 @@ public boolean equals(Object o) public int hashCode() { int result = fieldName != null ? fieldName.hashCode() : 0; - result = 31 * result + (expression != null ? expression.hashCode() : 0); result = 31 * result + (name != null ? name.hashCode() : 0); return result; } diff --git a/processing/src/main/java/io/druid/query/aggregation/DoubleMinAggregatorFactory.java b/processing/src/main/java/io/druid/query/aggregation/DoubleMinAggregatorFactory.java index bec58003a329..6fddde2d3a98 100644 --- a/processing/src/main/java/io/druid/query/aggregation/DoubleMinAggregatorFactory.java +++ b/processing/src/main/java/io/druid/query/aggregation/DoubleMinAggregatorFactory.java @@ -22,11 +22,10 @@ import com.fasterxml.jackson.annotation.JsonCreator; import com.fasterxml.jackson.annotation.JsonProperty; import com.google.common.base.Preconditions; +import com.google.common.collect.ImmutableList; import com.google.common.primitives.Doubles; import io.druid.common.utils.StringUtils; -import io.druid.math.expr.Parser; import io.druid.segment.ColumnSelectorFactory; -import io.druid.segment.FloatColumnSelector; import java.nio.ByteBuffer; import java.util.Arrays; @@ -42,46 +41,30 @@ public class DoubleMinAggregatorFactory extends AggregatorFactory private final String name; private final String fieldName; - private final String expression; @JsonCreator public DoubleMinAggregatorFactory( @JsonProperty("name") String name, - @JsonProperty("fieldName") final String fieldName, - @JsonProperty("expression") String expression + @JsonProperty("fieldName") final String fieldName ) { Preconditions.checkNotNull(name, "Must have a valid, non-null aggregator name"); - Preconditions.checkArgument( - fieldName == null ^ expression == null, - "Must have a valid, non-null fieldName or expression" - ); + Preconditions.checkNotNull(fieldName, "Must have a valid, non-null fieldName"); this.name = name; this.fieldName = fieldName; - this.expression = expression; - } - - public DoubleMinAggregatorFactory(String name, String fieldName) - { - this(name, fieldName, null); } @Override public Aggregator factorize(ColumnSelectorFactory metricFactory) { - return new DoubleMinAggregator(getFloatColumnSelector(metricFactory)); + return new DoubleMinAggregator(metricFactory.makeFloatColumnSelector(fieldName)); } @Override public BufferAggregator factorizeBuffered(ColumnSelectorFactory metricFactory) { - return new DoubleMinBufferAggregator(getFloatColumnSelector(metricFactory)); - } - - private FloatColumnSelector getFloatColumnSelector(ColumnSelectorFactory metricFactory) - { - return AggregatorUtil.getFloatColumnSelector(metricFactory, fieldName, expression, Float.MAX_VALUE); + return new DoubleMinBufferAggregator(metricFactory.makeFloatColumnSelector(fieldName)); } @Override @@ -99,7 +82,7 @@ public Object combine(Object lhs, Object rhs) @Override public AggregatorFactory getCombiningFactory() { - return new DoubleMinAggregatorFactory(name, name, null); + return new DoubleMinAggregatorFactory(name, name); } @Override @@ -115,7 +98,7 @@ public AggregatorFactory getMergingFactory(AggregatorFactory other) throws Aggre @Override public List getRequiredColumns() { - return Arrays.asList(new DoubleMinAggregatorFactory(fieldName, fieldName, expression)); + return Arrays.asList(new DoubleMinAggregatorFactory(fieldName, fieldName)); } @Override @@ -140,12 +123,6 @@ public String getFieldName() return fieldName; } - @JsonProperty - public String getExpression() - { - return expression; - } - @Override @JsonProperty public String getName() @@ -156,20 +133,17 @@ public String getName() @Override public List requiredFields() { - return fieldName != null ? Arrays.asList(fieldName) : Parser.findRequiredBindings(expression); + return ImmutableList.of(fieldName); } @Override public byte[] getCacheKey() { byte[] fieldNameBytes = StringUtils.toUtf8WithNullToEmpty(fieldName); - byte[] expressionBytes = StringUtils.toUtf8WithNullToEmpty(expression); - return ByteBuffer.allocate(2 + fieldNameBytes.length + expressionBytes.length) + return ByteBuffer.allocate(1 + fieldNameBytes.length) .put(CACHE_TYPE_ID) .put(fieldNameBytes) - .put(AggregatorUtil.STRING_SEPARATOR) - .put(expressionBytes) .array(); } @@ -190,7 +164,6 @@ public String toString() { return "DoubleMinAggregatorFactory{" + "fieldName='" + fieldName + '\'' + - ", expression='" + expression + '\'' + ", name='" + name + '\'' + '}'; } @@ -210,9 +183,6 @@ public boolean equals(Object o) if (!Objects.equals(fieldName, that.fieldName)) { return false; } - if (!Objects.equals(expression, that.expression)) { - return false; - } if (!Objects.equals(name, that.name)) { return false; } @@ -224,7 +194,6 @@ public boolean equals(Object o) public int hashCode() { int result = fieldName != null ? fieldName.hashCode() : 0; - result = 31 * result + (expression != null ? expression.hashCode() : 0); result = 31 * result + (name != null ? name.hashCode() : 0); return result; } diff --git a/processing/src/main/java/io/druid/query/aggregation/DoubleSumAggregatorFactory.java b/processing/src/main/java/io/druid/query/aggregation/DoubleSumAggregatorFactory.java index fa2b172fea83..538d128aa0aa 100644 --- a/processing/src/main/java/io/druid/query/aggregation/DoubleSumAggregatorFactory.java +++ b/processing/src/main/java/io/druid/query/aggregation/DoubleSumAggregatorFactory.java @@ -22,11 +22,10 @@ import com.fasterxml.jackson.annotation.JsonCreator; import com.fasterxml.jackson.annotation.JsonProperty; import com.google.common.base.Preconditions; +import com.google.common.collect.ImmutableList; import com.google.common.primitives.Doubles; import io.druid.common.utils.StringUtils; -import io.druid.math.expr.Parser; import io.druid.segment.ColumnSelectorFactory; -import io.druid.segment.FloatColumnSelector; import java.nio.ByteBuffer; import java.util.Arrays; @@ -42,46 +41,30 @@ public class DoubleSumAggregatorFactory extends AggregatorFactory private final String name; private final String fieldName; - private final String expression; @JsonCreator public DoubleSumAggregatorFactory( @JsonProperty("name") String name, - @JsonProperty("fieldName") String fieldName, - @JsonProperty("expression") String expression + @JsonProperty("fieldName") String fieldName ) { Preconditions.checkNotNull(name, "Must have a valid, non-null aggregator name"); - Preconditions.checkArgument( - fieldName == null ^ expression == null, - "Must have a valid, non-null fieldName or expression" - ); + Preconditions.checkNotNull(fieldName, "Must have a valid, non-null fieldName"); this.name = name; this.fieldName = fieldName; - this.expression = expression; - } - - public DoubleSumAggregatorFactory(String name, String fieldName) - { - this(name, fieldName, null); } @Override public Aggregator factorize(ColumnSelectorFactory metricFactory) { - return new DoubleSumAggregator(getFloatColumnSelector(metricFactory)); + return new DoubleSumAggregator(metricFactory.makeFloatColumnSelector(fieldName)); } @Override public BufferAggregator factorizeBuffered(ColumnSelectorFactory metricFactory) { - return new DoubleSumBufferAggregator(getFloatColumnSelector(metricFactory)); - } - - private FloatColumnSelector getFloatColumnSelector(ColumnSelectorFactory metricFactory) - { - return AggregatorUtil.getFloatColumnSelector(metricFactory, fieldName, expression, 0f); + return new DoubleSumBufferAggregator(metricFactory.makeFloatColumnSelector(fieldName)); } @Override @@ -99,7 +82,7 @@ public Object combine(Object lhs, Object rhs) @Override public AggregatorFactory getCombiningFactory() { - return new DoubleSumAggregatorFactory(name, name, null); + return new DoubleSumAggregatorFactory(name, name); } @Override @@ -115,7 +98,7 @@ public AggregatorFactory getMergingFactory(AggregatorFactory other) throws Aggre @Override public List getRequiredColumns() { - return Arrays.asList(new DoubleSumAggregatorFactory(fieldName, fieldName, expression)); + return Arrays.asList(new DoubleSumAggregatorFactory(fieldName, fieldName)); } @Override @@ -140,12 +123,6 @@ public String getFieldName() return fieldName; } - @JsonProperty - public String getExpression() - { - return expression; - } - @Override @JsonProperty public String getName() @@ -156,20 +133,17 @@ public String getName() @Override public List requiredFields() { - return fieldName != null ? Arrays.asList(fieldName) : Parser.findRequiredBindings(expression); + return ImmutableList.of(fieldName); } @Override public byte[] getCacheKey() { byte[] fieldNameBytes = StringUtils.toUtf8WithNullToEmpty(fieldName); - byte[] expressionBytes = StringUtils.toUtf8WithNullToEmpty(expression); - return ByteBuffer.allocate(2 + fieldNameBytes.length + expressionBytes.length) + return ByteBuffer.allocate(1 + fieldNameBytes.length) .put(CACHE_TYPE_ID) .put(fieldNameBytes) - .put(AggregatorUtil.STRING_SEPARATOR) - .put(expressionBytes) .array(); } @@ -190,7 +164,6 @@ public String toString() { return "DoubleSumAggregatorFactory{" + "fieldName='" + fieldName + '\'' + - ", expression='" + expression + '\'' + ", name='" + name + '\'' + '}'; } @@ -210,9 +183,6 @@ public boolean equals(Object o) if (!Objects.equals(fieldName, that.fieldName)) { return false; } - if (!Objects.equals(expression, that.expression)) { - return false; - } if (!Objects.equals(name, that.name)) { return false; } @@ -224,7 +194,6 @@ public boolean equals(Object o) public int hashCode() { int result = fieldName != null ? fieldName.hashCode() : 0; - result = 31 * result + (expression != null ? expression.hashCode() : 0); result = 31 * result + (name != null ? name.hashCode() : 0); return result; } diff --git a/processing/src/main/java/io/druid/query/aggregation/FilteredAggregatorFactory.java b/processing/src/main/java/io/druid/query/aggregation/FilteredAggregatorFactory.java index 9e830f71df8d..2186b354a7bc 100644 --- a/processing/src/main/java/io/druid/query/aggregation/FilteredAggregatorFactory.java +++ b/processing/src/main/java/io/druid/query/aggregation/FilteredAggregatorFactory.java @@ -31,8 +31,6 @@ import io.druid.query.filter.ValueMatcherFactory; import io.druid.segment.ColumnSelectorFactory; import io.druid.segment.DimensionSelector; -import io.druid.segment.column.Column; -import io.druid.segment.column.ColumnCapabilities; import io.druid.segment.column.ValueType; import io.druid.segment.data.IndexedInts; import io.druid.segment.filter.BooleanValueMatcher; @@ -221,7 +219,7 @@ public FilteredAggregatorValueMatcherFactory(ColumnSelectorFactory columnSelecto @Override public ValueMatcher makeValueMatcher(final String dimension, final String value) { - if (getTypeForDimension(dimension) == ValueType.LONG) { + if (getNativeType(dimension) == ValueType.LONG) { return Filters.getLongValueMatcher( columnSelectorFactory.makeLongColumnSelector(dimension), value @@ -293,7 +291,7 @@ public boolean matches() public ValueMatcher makeValueMatcher(final String dimension, final DruidPredicateFactory predicateFactory) { - ValueType type = getTypeForDimension(dimension); + final ValueType type = getNativeType(dimension); switch (type) { case LONG: return makeLongValueMatcher(dimension, predicateFactory.makeLongPredicate()); @@ -380,16 +378,10 @@ private ValueMatcher makeLongValueMatcher(String dimension, DruidLongPredicate p ); } - private ValueType getTypeForDimension(String dimension) + private ValueType getNativeType(String columnName) { - // FilteredAggregatorFactory is sometimes created from a ColumnSelectorFactory that - // has no knowledge of column capabilities/types. - // Default to LONG for __time, STRING for everything else. - if (dimension.equals(Column.TIME_COLUMN_NAME)) { - return ValueType.LONG; - } - ColumnCapabilities capabilities = columnSelectorFactory.getColumnCapabilities(dimension); - return capabilities == null ? ValueType.STRING : capabilities.getType(); + final ValueType nativeType = columnSelectorFactory.getNativeType(columnName); + return nativeType == null ? ValueType.STRING : nativeType; } } } diff --git a/processing/src/main/java/io/druid/query/aggregation/LongMaxAggregatorFactory.java b/processing/src/main/java/io/druid/query/aggregation/LongMaxAggregatorFactory.java index e777de612617..6ebddb397a44 100644 --- a/processing/src/main/java/io/druid/query/aggregation/LongMaxAggregatorFactory.java +++ b/processing/src/main/java/io/druid/query/aggregation/LongMaxAggregatorFactory.java @@ -22,11 +22,10 @@ import com.fasterxml.jackson.annotation.JsonCreator; import com.fasterxml.jackson.annotation.JsonProperty; import com.google.common.base.Preconditions; +import com.google.common.collect.ImmutableList; import com.google.common.primitives.Longs; import io.druid.common.utils.StringUtils; -import io.druid.math.expr.Parser; import io.druid.segment.ColumnSelectorFactory; -import io.druid.segment.LongColumnSelector; import java.nio.ByteBuffer; import java.util.Arrays; @@ -42,46 +41,30 @@ public class LongMaxAggregatorFactory extends AggregatorFactory private final String name; private final String fieldName; - private final String expression; @JsonCreator public LongMaxAggregatorFactory( @JsonProperty("name") String name, - @JsonProperty("fieldName") final String fieldName, - @JsonProperty("expression") String expression + @JsonProperty("fieldName") final String fieldName ) { Preconditions.checkNotNull(name, "Must have a valid, non-null aggregator name"); - Preconditions.checkArgument( - fieldName == null ^ expression == null, - "Must have a valid, non-null fieldName or expression" - ); + Preconditions.checkNotNull(fieldName, "Must have a valid, non-null fieldName"); this.name = name; this.fieldName = fieldName; - this.expression = expression; - } - - public LongMaxAggregatorFactory(String name, String fieldName) - { - this(name, fieldName, null); } @Override public Aggregator factorize(ColumnSelectorFactory metricFactory) { - return new LongMaxAggregator(getLongColumnSelector(metricFactory)); + return new LongMaxAggregator(metricFactory.makeLongColumnSelector(fieldName)); } @Override public BufferAggregator factorizeBuffered(ColumnSelectorFactory metricFactory) { - return new LongMaxBufferAggregator(getLongColumnSelector(metricFactory)); - } - - private LongColumnSelector getLongColumnSelector(ColumnSelectorFactory metricFactory) - { - return AggregatorUtil.getLongColumnSelector(metricFactory, fieldName, expression, Long.MIN_VALUE); + return new LongMaxBufferAggregator(metricFactory.makeLongColumnSelector(fieldName)); } @Override @@ -99,7 +82,7 @@ public Object combine(Object lhs, Object rhs) @Override public AggregatorFactory getCombiningFactory() { - return new LongMaxAggregatorFactory(name, name, null); + return new LongMaxAggregatorFactory(name, name); } @Override @@ -115,7 +98,7 @@ public AggregatorFactory getMergingFactory(AggregatorFactory other) throws Aggre @Override public List getRequiredColumns() { - return Arrays.asList(new LongMaxAggregatorFactory(fieldName, fieldName, expression)); + return Arrays.asList(new LongMaxAggregatorFactory(fieldName, fieldName)); } @Override @@ -136,12 +119,6 @@ public String getFieldName() return fieldName; } - @JsonProperty - public String getExpression() - { - return expression; - } - @Override @JsonProperty public String getName() @@ -152,20 +129,17 @@ public String getName() @Override public List requiredFields() { - return fieldName != null ? Arrays.asList(fieldName) : Parser.findRequiredBindings(expression); + return ImmutableList.of(fieldName); } @Override public byte[] getCacheKey() { byte[] fieldNameBytes = StringUtils.toUtf8WithNullToEmpty(fieldName); - byte[] expressionBytes = StringUtils.toUtf8WithNullToEmpty(expression); - return ByteBuffer.allocate(2 + fieldNameBytes.length + expressionBytes.length) + return ByteBuffer.allocate(1 + fieldNameBytes.length) .put(CACHE_TYPE_ID) .put(fieldNameBytes) - .put(AggregatorUtil.STRING_SEPARATOR) - .put(expressionBytes) .array(); } @@ -186,7 +160,6 @@ public String toString() { return "LongMaxAggregatorFactory{" + "fieldName='" + fieldName + '\'' + - ", expression='" + expression + '\'' + ", name='" + name + '\'' + '}'; } @@ -206,9 +179,6 @@ public boolean equals(Object o) if (!Objects.equals(fieldName, that.fieldName)) { return false; } - if (!Objects.equals(expression, that.expression)) { - return false; - } if (!Objects.equals(name, that.name)) { return false; } @@ -220,7 +190,6 @@ public boolean equals(Object o) public int hashCode() { int result = fieldName != null ? fieldName.hashCode() : 0; - result = 31 * result + (expression != null ? expression.hashCode() : 0); result = 31 * result + (name != null ? name.hashCode() : 0); return result; } diff --git a/processing/src/main/java/io/druid/query/aggregation/LongMinAggregatorFactory.java b/processing/src/main/java/io/druid/query/aggregation/LongMinAggregatorFactory.java index 52317f4bd2f3..f50c6e3c45ad 100644 --- a/processing/src/main/java/io/druid/query/aggregation/LongMinAggregatorFactory.java +++ b/processing/src/main/java/io/druid/query/aggregation/LongMinAggregatorFactory.java @@ -22,11 +22,10 @@ import com.fasterxml.jackson.annotation.JsonCreator; import com.fasterxml.jackson.annotation.JsonProperty; import com.google.common.base.Preconditions; +import com.google.common.collect.ImmutableList; import com.google.common.primitives.Longs; import io.druid.common.utils.StringUtils; -import io.druid.math.expr.Parser; import io.druid.segment.ColumnSelectorFactory; -import io.druid.segment.LongColumnSelector; import java.nio.ByteBuffer; import java.util.Arrays; @@ -42,46 +41,30 @@ public class LongMinAggregatorFactory extends AggregatorFactory private final String name; private final String fieldName; - private final String expression; @JsonCreator public LongMinAggregatorFactory( @JsonProperty("name") String name, - @JsonProperty("fieldName") final String fieldName, - @JsonProperty("expression") String expression + @JsonProperty("fieldName") final String fieldName ) { Preconditions.checkNotNull(name, "Must have a valid, non-null aggregator name"); - Preconditions.checkArgument( - fieldName == null ^ expression == null, - "Must have a valid, non-null fieldName or expression" - ); + Preconditions.checkNotNull(fieldName, "Must have a valid, non-null fieldName"); this.name = name; this.fieldName = fieldName; - this.expression = expression; - } - - public LongMinAggregatorFactory(String name, String fieldName) - { - this(name, fieldName, null); } @Override public Aggregator factorize(ColumnSelectorFactory metricFactory) { - return new LongMinAggregator(getLongColumnSelector(metricFactory)); + return new LongMinAggregator(metricFactory.makeLongColumnSelector(fieldName)); } @Override public BufferAggregator factorizeBuffered(ColumnSelectorFactory metricFactory) { - return new LongMinBufferAggregator(getLongColumnSelector(metricFactory)); - } - - private LongColumnSelector getLongColumnSelector(ColumnSelectorFactory metricFactory) - { - return AggregatorUtil.getLongColumnSelector(metricFactory, fieldName, expression, Long.MAX_VALUE); + return new LongMinBufferAggregator(metricFactory.makeLongColumnSelector(fieldName)); } @Override @@ -99,7 +82,7 @@ public Object combine(Object lhs, Object rhs) @Override public AggregatorFactory getCombiningFactory() { - return new LongMinAggregatorFactory(name, name, null); + return new LongMinAggregatorFactory(name, name); } @Override @@ -115,7 +98,7 @@ public AggregatorFactory getMergingFactory(AggregatorFactory other) throws Aggre @Override public List getRequiredColumns() { - return Arrays.asList(new LongMinAggregatorFactory(fieldName, fieldName, expression)); + return Arrays.asList(new LongMinAggregatorFactory(fieldName, fieldName)); } @Override @@ -136,12 +119,6 @@ public String getFieldName() return fieldName; } - @JsonProperty - public String getExpression() - { - return expression; - } - @Override @JsonProperty public String getName() @@ -152,20 +129,17 @@ public String getName() @Override public List requiredFields() { - return fieldName != null ? Arrays.asList(fieldName) : Parser.findRequiredBindings(expression); + return ImmutableList.of(fieldName); } @Override public byte[] getCacheKey() { byte[] fieldNameBytes = StringUtils.toUtf8WithNullToEmpty(fieldName); - byte[] expressionBytes = StringUtils.toUtf8WithNullToEmpty(expression); - return ByteBuffer.allocate(2 + fieldNameBytes.length + expressionBytes.length) + return ByteBuffer.allocate(1 + fieldNameBytes.length) .put(CACHE_TYPE_ID) .put(fieldNameBytes) - .put(AggregatorUtil.STRING_SEPARATOR) - .put(expressionBytes) .array(); } @@ -186,7 +160,6 @@ public String toString() { return "LongMinAggregatorFactory{" + "fieldName='" + fieldName + '\'' + - ", expression='" + expression + '\'' + ", name='" + name + '\'' + '}'; } @@ -206,9 +179,6 @@ public boolean equals(Object o) if (!Objects.equals(fieldName, that.fieldName)) { return false; } - if (!Objects.equals(expression, that.expression)) { - return false; - } if (!Objects.equals(name, that.name)) { return false; } @@ -220,7 +190,6 @@ public boolean equals(Object o) public int hashCode() { int result = fieldName != null ? fieldName.hashCode() : 0; - result = 31 * result + (expression != null ? expression.hashCode() : 0); result = 31 * result + (name != null ? name.hashCode() : 0); return result; } diff --git a/processing/src/main/java/io/druid/query/aggregation/LongSumAggregatorFactory.java b/processing/src/main/java/io/druid/query/aggregation/LongSumAggregatorFactory.java index 6c5679af332b..05acd7c1d3b9 100644 --- a/processing/src/main/java/io/druid/query/aggregation/LongSumAggregatorFactory.java +++ b/processing/src/main/java/io/druid/query/aggregation/LongSumAggregatorFactory.java @@ -22,11 +22,10 @@ import com.fasterxml.jackson.annotation.JsonCreator; import com.fasterxml.jackson.annotation.JsonProperty; import com.google.common.base.Preconditions; +import com.google.common.collect.ImmutableList; import com.google.common.primitives.Longs; import io.druid.common.utils.StringUtils; -import io.druid.math.expr.Parser; import io.druid.segment.ColumnSelectorFactory; -import io.druid.segment.LongColumnSelector; import java.nio.ByteBuffer; import java.util.Arrays; @@ -42,46 +41,30 @@ public class LongSumAggregatorFactory extends AggregatorFactory private final String name; private final String fieldName; - private final String expression; @JsonCreator public LongSumAggregatorFactory( @JsonProperty("name") String name, - @JsonProperty("fieldName") String fieldName, - @JsonProperty("expression") String expression + @JsonProperty("fieldName") String fieldName ) { Preconditions.checkNotNull(name, "Must have a valid, non-null aggregator name"); - Preconditions.checkArgument( - fieldName == null ^ expression == null, - "Must have a valid, non-null fieldName or expression" - ); + Preconditions.checkNotNull(fieldName, "Must have a valid, non-null fieldName"); this.name = name; this.fieldName = fieldName; - this.expression = expression; - } - - public LongSumAggregatorFactory(String name, String fieldName) - { - this(name, fieldName, null); } @Override public Aggregator factorize(ColumnSelectorFactory metricFactory) { - return new LongSumAggregator(getLongColumnSelector(metricFactory)); + return new LongSumAggregator(metricFactory.makeLongColumnSelector(fieldName)); } @Override public BufferAggregator factorizeBuffered(ColumnSelectorFactory metricFactory) { - return new LongSumBufferAggregator(getLongColumnSelector(metricFactory)); - } - - private LongColumnSelector getLongColumnSelector(ColumnSelectorFactory metricFactory) - { - return AggregatorUtil.getLongColumnSelector(metricFactory, fieldName, expression, 0L); + return new LongSumBufferAggregator(metricFactory.makeLongColumnSelector(fieldName)); } @Override @@ -99,7 +82,7 @@ public Object combine(Object lhs, Object rhs) @Override public AggregatorFactory getCombiningFactory() { - return new LongSumAggregatorFactory(name, name, null); + return new LongSumAggregatorFactory(name, name); } @Override @@ -115,7 +98,7 @@ public AggregatorFactory getMergingFactory(AggregatorFactory other) throws Aggre @Override public List getRequiredColumns() { - return Arrays.asList(new LongSumAggregatorFactory(fieldName, fieldName, expression)); + return Arrays.asList(new LongSumAggregatorFactory(fieldName, fieldName)); } @Override @@ -136,12 +119,6 @@ public String getFieldName() return fieldName; } - @JsonProperty - public String getExpression() - { - return expression; - } - @Override @JsonProperty public String getName() @@ -152,20 +129,17 @@ public String getName() @Override public List requiredFields() { - return fieldName != null ? Arrays.asList(fieldName) : Parser.findRequiredBindings(expression); + return ImmutableList.of(fieldName); } @Override public byte[] getCacheKey() { byte[] fieldNameBytes = StringUtils.toUtf8WithNullToEmpty(fieldName); - byte[] expressionBytes = StringUtils.toUtf8WithNullToEmpty(expression); - return ByteBuffer.allocate(2 + fieldNameBytes.length + expressionBytes.length) + return ByteBuffer.allocate(1 + fieldNameBytes.length) .put(CACHE_TYPE_ID) .put(fieldNameBytes) - .put(AggregatorUtil.STRING_SEPARATOR) - .put(expressionBytes) .array(); } @@ -186,7 +160,6 @@ public String toString() { return "LongSumAggregatorFactory{" + "fieldName='" + fieldName + '\'' + - ", expression='" + expression + '\'' + ", name='" + name + '\'' + '}'; } @@ -206,9 +179,6 @@ public boolean equals(Object o) if (!Objects.equals(fieldName, that.fieldName)) { return false; } - if (!Objects.equals(expression, that.expression)) { - return false; - } if (!Objects.equals(name, that.name)) { return false; } @@ -220,7 +190,6 @@ public boolean equals(Object o) public int hashCode() { int result = fieldName != null ? fieldName.hashCode() : 0; - result = 31 * result + (expression != null ? expression.hashCode() : 0); result = 31 * result + (name != null ? name.hashCode() : 0); return result; } diff --git a/processing/src/main/java/io/druid/query/groupby/GroupByQuery.java b/processing/src/main/java/io/druid/query/groupby/GroupByQuery.java index 7df97a4c56e5..fe6103623e3a 100644 --- a/processing/src/main/java/io/druid/query/groupby/GroupByQuery.java +++ b/processing/src/main/java/io/druid/query/groupby/GroupByQuery.java @@ -56,8 +56,11 @@ import io.druid.query.groupby.orderby.OrderByColumnSpec; import io.druid.query.spec.LegacySegmentSpec; import io.druid.query.spec.QuerySegmentSpec; +import io.druid.segment.VirtualColumn; +import io.druid.segment.VirtualColumns; import org.joda.time.Interval; +import java.util.Arrays; import java.util.Comparator; import java.util.List; import java.util.Map; @@ -88,6 +91,7 @@ public static Builder builder() return new Builder(); } + private final VirtualColumns virtualColumns; private final LimitSpec limitSpec; private final HavingSpec havingSpec; private final DimFilter dimFilter; @@ -102,6 +106,7 @@ public static Builder builder() public GroupByQuery( @JsonProperty("dataSource") DataSource dataSource, @JsonProperty("intervals") QuerySegmentSpec querySegmentSpec, + @JsonProperty("virtualColumns") VirtualColumns virtualColumns, @JsonProperty("filter") DimFilter dimFilter, @JsonProperty("granularity") QueryGranularity granularity, @JsonProperty("dimensions") List dimensions, @@ -113,6 +118,7 @@ public GroupByQuery( ) { super(dataSource, querySegmentSpec, false, context); + this.virtualColumns = virtualColumns == null ? VirtualColumns.EMPTY : virtualColumns; this.dimFilter = dimFilter; this.granularity = granularity; this.dimensions = dimensions == null ? ImmutableList.of() : dimensions; @@ -169,6 +175,7 @@ public boolean apply(Row input) private GroupByQuery( DataSource dataSource, QuerySegmentSpec querySegmentSpec, + VirtualColumns virtualColumns, DimFilter dimFilter, QueryGranularity granularity, List dimensions, @@ -182,6 +189,7 @@ private GroupByQuery( { super(dataSource, querySegmentSpec, false, context); + this.virtualColumns = virtualColumns; this.dimFilter = dimFilter; this.granularity = granularity; this.dimensions = dimensions; @@ -192,6 +200,12 @@ private GroupByQuery( this.limitFn = limitFn; } + @JsonProperty + public VirtualColumns getVirtualColumns() + { + return virtualColumns; + } + @JsonProperty("filter") public DimFilter getDimFilter() { @@ -380,6 +394,7 @@ public GroupByQuery withOverriddenContext(Map contextOverride) return new GroupByQuery( getDataSource(), getQuerySegmentSpec(), + virtualColumns, dimFilter, granularity, dimensions, @@ -398,6 +413,7 @@ public GroupByQuery withQuerySegmentSpec(QuerySegmentSpec spec) return new GroupByQuery( getDataSource(), spec, + virtualColumns, dimFilter, granularity, dimensions, @@ -415,6 +431,7 @@ public GroupByQuery withDimFilter(final DimFilter dimFilter) return new GroupByQuery( getDataSource(), getQuerySegmentSpec(), + virtualColumns, dimFilter, getGranularity(), getDimensions(), @@ -433,6 +450,7 @@ public Query withDataSource(DataSource dataSource) return new GroupByQuery( dataSource, getQuerySegmentSpec(), + virtualColumns, dimFilter, granularity, dimensions, @@ -450,6 +468,7 @@ public GroupByQuery withDimensionSpecs(final List dimensionSpecs) return new GroupByQuery( getDataSource(), getQuerySegmentSpec(), + virtualColumns, getDimFilter(), getGranularity(), dimensionSpecs, @@ -467,6 +486,7 @@ public GroupByQuery withLimitSpec(final LimitSpec limitSpec) return new GroupByQuery( getDataSource(), getQuerySegmentSpec(), + virtualColumns, getDimFilter(), getGranularity(), getDimensions(), @@ -483,6 +503,7 @@ public GroupByQuery withAggregatorSpecs(final List aggregator return new GroupByQuery( getDataSource(), getQuerySegmentSpec(), + virtualColumns, getDimFilter(), getGranularity(), getDimensions(), @@ -500,6 +521,7 @@ public GroupByQuery withPostAggregatorSpecs(final List postAggre return new GroupByQuery( getDataSource(), getQuerySegmentSpec(), + virtualColumns, getDimFilter(), getGranularity(), getDimensions(), @@ -542,6 +564,7 @@ public static class Builder { private DataSource dataSource; private QuerySegmentSpec querySegmentSpec; + private VirtualColumns virtualColumns; private DimFilter dimFilter; private QueryGranularity granularity; private List dimensions; @@ -563,6 +586,7 @@ public Builder(GroupByQuery query) { dataSource = query.getDataSource(); querySegmentSpec = query.getQuerySegmentSpec(); + virtualColumns = query.getVirtualColumns(); limitSpec = query.getLimitSpec(); dimFilter = query.getDimFilter(); granularity = query.getGranularity(); @@ -577,6 +601,7 @@ public Builder(Builder builder) { dataSource = builder.dataSource; querySegmentSpec = builder.querySegmentSpec; + virtualColumns = builder.virtualColumns; limitSpec = builder.limitSpec; dimFilter = builder.dimFilter; granularity = builder.granularity; @@ -627,6 +652,15 @@ public Builder setInterval(String interval) return setQuerySegmentSpec(new LegacySegmentSpec(interval)); } + public Builder setVirtualColumns(List virtualColumns) { + this.virtualColumns = VirtualColumns.create(virtualColumns); + return this; + } + + public Builder setVirtualColumns(VirtualColumn... virtualColumns) { + return setVirtualColumns(Arrays.asList(virtualColumns)); + } + public Builder limit(int limit) { ensureExplicitLimitNotSet(); @@ -789,6 +823,7 @@ public GroupByQuery build() return new GroupByQuery( dataSource, querySegmentSpec, + virtualColumns, dimFilter, granularity, dimensions, @@ -801,22 +836,6 @@ public GroupByQuery build() } } - @Override - public String toString() - { - return "GroupByQuery{" + - "dataSource='" + getDataSource() + '\'' + - ", querySegmentSpec=" + getQuerySegmentSpec() + - ", limitSpec=" + limitSpec + - ", dimFilter=" + dimFilter + - ", granularity=" + granularity + - ", dimensions=" + dimensions + - ", aggregatorSpecs=" + aggregatorSpecs + - ", postAggregatorSpecs=" + postAggregatorSpecs + - ", havingSpec=" + havingSpec + - '}'; - } - @Override public boolean equals(Object o) { @@ -832,44 +851,57 @@ public boolean equals(Object o) GroupByQuery that = (GroupByQuery) o; - if (aggregatorSpecs != null ? !aggregatorSpecs.equals(that.aggregatorSpecs) : that.aggregatorSpecs != null) { + if (!virtualColumns.equals(that.virtualColumns)) { return false; } - if (dimFilter != null ? !dimFilter.equals(that.dimFilter) : that.dimFilter != null) { + if (!limitSpec.equals(that.limitSpec)) { return false; } - if (dimensions != null ? !dimensions.equals(that.dimensions) : that.dimensions != null) { + if (havingSpec != null ? !havingSpec.equals(that.havingSpec) : that.havingSpec != null) { return false; } - if (granularity != null ? !granularity.equals(that.granularity) : that.granularity != null) { + if (dimFilter != null ? !dimFilter.equals(that.dimFilter) : that.dimFilter != null) { return false; } - if (havingSpec != null ? !havingSpec.equals(that.havingSpec) : that.havingSpec != null) { + if (granularity != null ? !granularity.equals(that.granularity) : that.granularity != null) { return false; } - if (limitSpec != null ? !limitSpec.equals(that.limitSpec) : that.limitSpec != null) { + if (!dimensions.equals(that.dimensions)) { return false; } - if (postAggregatorSpecs != null - ? !postAggregatorSpecs.equals(that.postAggregatorSpecs) - : that.postAggregatorSpecs != null) { + if (!aggregatorSpecs.equals(that.aggregatorSpecs)) { return false; } - - return true; + return postAggregatorSpecs.equals(that.postAggregatorSpecs); } @Override public int hashCode() { int result = super.hashCode(); - result = 31 * result + (limitSpec != null ? limitSpec.hashCode() : 0); + result = 31 * result + virtualColumns.hashCode(); + result = 31 * result + limitSpec.hashCode(); result = 31 * result + (havingSpec != null ? havingSpec.hashCode() : 0); result = 31 * result + (dimFilter != null ? dimFilter.hashCode() : 0); result = 31 * result + (granularity != null ? granularity.hashCode() : 0); - result = 31 * result + (dimensions != null ? dimensions.hashCode() : 0); - result = 31 * result + (aggregatorSpecs != null ? aggregatorSpecs.hashCode() : 0); - result = 31 * result + (postAggregatorSpecs != null ? postAggregatorSpecs.hashCode() : 0); + result = 31 * result + dimensions.hashCode(); + result = 31 * result + aggregatorSpecs.hashCode(); + result = 31 * result + postAggregatorSpecs.hashCode(); return result; } + + @Override + public String toString() + { + return "GroupByQuery{" + + "virtualColumns=" + virtualColumns + + ", limitSpec=" + limitSpec + + ", havingSpec=" + havingSpec + + ", dimFilter=" + dimFilter + + ", granularity=" + granularity + + ", dimensions=" + dimensions + + ", aggregations=" + aggregatorSpecs + + ", postAggregations=" + postAggregatorSpecs + + '}'; + } } diff --git a/processing/src/main/java/io/druid/query/groupby/GroupByQueryEngine.java b/processing/src/main/java/io/druid/query/groupby/GroupByQueryEngine.java index d78f64bb61f1..1b3fd3e5e04e 100644 --- a/processing/src/main/java/io/druid/query/groupby/GroupByQueryEngine.java +++ b/processing/src/main/java/io/druid/query/groupby/GroupByQueryEngine.java @@ -48,7 +48,6 @@ import io.druid.segment.Cursor; import io.druid.segment.DimensionSelector; import io.druid.segment.StorageAdapter; -import io.druid.segment.VirtualColumns; import io.druid.segment.data.IndexedInts; import io.druid.segment.filter.Filters; import org.joda.time.DateTime; @@ -101,7 +100,7 @@ public Sequence process(final GroupByQuery query, final StorageAdapter stor final Sequence cursors = storageAdapter.makeCursors( filter, intervals.get(0), - VirtualColumns.EMPTY, + query.getVirtualColumns(), query.getGranularity(), false ); diff --git a/processing/src/main/java/io/druid/query/groupby/GroupByQueryQueryToolChest.java b/processing/src/main/java/io/druid/query/groupby/GroupByQueryQueryToolChest.java index 436e9d31ce5a..21aaf8e1eadf 100644 --- a/processing/src/main/java/io/druid/query/groupby/GroupByQueryQueryToolChest.java +++ b/processing/src/main/java/io/druid/query/groupby/GroupByQueryQueryToolChest.java @@ -355,6 +355,7 @@ public byte[] computeCacheKey(GroupByQuery query) } final byte[] havingBytes = query.getHavingSpec() == null ? new byte[]{} : query.getHavingSpec().getCacheKey(); final byte[] limitBytes = query.getLimitSpec().getCacheKey(); + final byte[] virtualColumnsBytes = query.getVirtualColumns().getCacheKey(); ByteBuffer buffer = ByteBuffer .allocate( @@ -365,6 +366,7 @@ public byte[] computeCacheKey(GroupByQuery query) + dimensionsBytesSize + havingBytes.length + limitBytes.length + + virtualColumnsBytes.length ) .put(GROUPBY_QUERY) .put(CACHE_STRATEGY_VERSION) @@ -379,6 +381,7 @@ public byte[] computeCacheKey(GroupByQuery query) return buffer .put(havingBytes) .put(limitBytes) + .put(virtualColumnsBytes) .array(); } diff --git a/processing/src/main/java/io/druid/query/groupby/epinephelinae/GroupByQueryEngineV2.java b/processing/src/main/java/io/druid/query/groupby/epinephelinae/GroupByQueryEngineV2.java index 7fdae22a87d4..08e0879544de 100644 --- a/processing/src/main/java/io/druid/query/groupby/epinephelinae/GroupByQueryEngineV2.java +++ b/processing/src/main/java/io/druid/query/groupby/epinephelinae/GroupByQueryEngineV2.java @@ -41,7 +41,6 @@ import io.druid.segment.Cursor; import io.druid.segment.DimensionSelector; import io.druid.segment.StorageAdapter; -import io.druid.segment.VirtualColumns; import io.druid.segment.data.EmptyIndexedInts; import io.druid.segment.data.IndexedInts; import io.druid.segment.filter.Filters; @@ -84,7 +83,7 @@ public static Sequence process( final Sequence cursors = storageAdapter.makeCursors( Filters.toFilter(query.getDimFilter()), intervals.get(0), - VirtualColumns.EMPTY, + query.getVirtualColumns(), query.getGranularity(), false ); diff --git a/processing/src/main/java/io/druid/query/groupby/epinephelinae/RowBasedGrouperHelper.java b/processing/src/main/java/io/druid/query/groupby/epinephelinae/RowBasedGrouperHelper.java index 33f014662fdb..c6c9cd2f74f3 100644 --- a/processing/src/main/java/io/druid/query/groupby/epinephelinae/RowBasedGrouperHelper.java +++ b/processing/src/main/java/io/druid/query/groupby/epinephelinae/RowBasedGrouperHelper.java @@ -25,7 +25,6 @@ import com.google.common.base.Function; import com.google.common.base.Preconditions; import com.google.common.base.Strings; -import com.google.common.base.Supplier; import com.google.common.collect.Lists; import com.google.common.collect.Maps; import com.google.common.primitives.Chars; @@ -36,9 +35,6 @@ import io.druid.granularity.AllGranularity; import io.druid.java.util.common.Pair; import io.druid.java.util.common.guava.Accumulator; -import io.druid.math.expr.Evals; -import io.druid.math.expr.Expr; -import io.druid.math.expr.Parser; import io.druid.query.QueryInterruptedException; import io.druid.query.aggregation.AggregatorFactory; import io.druid.query.dimension.DimensionSpec; @@ -50,10 +46,9 @@ import io.druid.segment.DimensionSelector; import io.druid.segment.FloatColumnSelector; import io.druid.segment.LongColumnSelector; -import io.druid.segment.NumericColumnSelector; import io.druid.segment.ObjectColumnSelector; import io.druid.segment.column.Column; -import io.druid.segment.column.ColumnCapabilities; +import io.druid.segment.column.ValueType; import io.druid.segment.data.IndexedInts; import it.unimi.dsi.fastutil.ints.IntIterator; import it.unimi.dsi.fastutil.ints.IntIterators; @@ -94,12 +89,14 @@ public static Pair, Accumulator, Row>> querySpecificConfig.getMaxMergingDictionarySize() / (concurrencyHint == -1 ? 1 : concurrencyHint) ); final RowBasedColumnSelectorFactory columnSelectorFactory = new RowBasedColumnSelectorFactory(); + final ColumnSelectorFactory virtualizedColumnSelectorFactory = query.getVirtualColumns() + .wrap(columnSelectorFactory); final Grouper grouper; if (concurrencyHint == -1) { grouper = new SpillingGrouper<>( buffer, keySerdeFactory, - columnSelectorFactory, + virtualizedColumnSelectorFactory, aggregatorFactories, querySpecificConfig.getBufferGrouperMaxSize(), querySpecificConfig.getBufferGrouperMaxLoadFactor(), @@ -112,7 +109,7 @@ public static Pair, Accumulator, Row>> grouper = new ConcurrentGrouper<>( buffer, keySerdeFactory, - columnSelectorFactory, + virtualizedColumnSelectorFactory, aggregatorFactories, querySpecificConfig.getBufferGrouperMaxSize(), querySpecificConfig.getBufferGrouperMaxLoadFactor(), @@ -127,7 +124,7 @@ public static Pair, Accumulator, Row>> if (isInputRaw) { dimensionSelectors = new DimensionSelector[query.getDimensions().size()]; for (int i = 0; i < dimensionSelectors.length; i++) { - dimensionSelectors[i] = columnSelectorFactory.makeDimensionSelector(query.getDimensions().get(i)); + dimensionSelectors[i] = virtualizedColumnSelectorFactory.makeDimensionSelector(query.getDimensions().get(i)); } } else { dimensionSelectors = null; @@ -777,42 +774,17 @@ public Object get() } @Override - public NumericColumnSelector makeMathExpressionSelector(String expression) + public ValueType getNativeType(String columnName) { - final Expr parsed = Parser.parse(expression); + // This ColumnSelectorFactory implementation has no innate knowledge of column types. All it knows + // is that TIME_COLUMN_NAME is a long. - final List required = Parser.findRequiredBindings(parsed); - final Map> values = Maps.newHashMapWithExpectedSize(required.size()); - - for (final String columnName : required) { - values.put( - columnName, new Supplier() - { - @Override - public Number get() - { - return Evals.toNumber(row.get().getRaw(columnName)); - } - } - ); + if (Column.TIME_COLUMN_NAME.equals(columnName)) { + return ValueType.LONG; + } else { + // Return null, caller will assume default types in this case. + return null; } - final Expr.ObjectBinding binding = Parser.withSuppliers(values); - - return new NumericColumnSelector() - { - @Override - public Number get() - { - return parsed.eval(binding).numericValue(); - } - }; - } - - @Override - public ColumnCapabilities getColumnCapabilities(String columnName) - { - // We don't have any information on the column value type, returning null defaults type to string - return null; } } diff --git a/processing/src/main/java/io/druid/query/groupby/strategy/GroupByStrategyV1.java b/processing/src/main/java/io/druid/query/groupby/strategy/GroupByStrategyV1.java index 9660a8c2bb7a..a292ff9a8743 100644 --- a/processing/src/main/java/io/druid/query/groupby/strategy/GroupByStrategyV1.java +++ b/processing/src/main/java/io/druid/query/groupby/strategy/GroupByStrategyV1.java @@ -93,6 +93,7 @@ public Sequence mergeResults( new GroupByQuery( query.getDataSource(), query.getQuerySegmentSpec(), + query.getVirtualColumns(), query.getDimFilter(), query.getGranularity(), query.getDimensions(), diff --git a/processing/src/main/java/io/druid/query/groupby/strategy/GroupByStrategyV2.java b/processing/src/main/java/io/druid/query/groupby/strategy/GroupByStrategyV2.java index 7e1ab35f6b9e..27401ebe0c05 100644 --- a/processing/src/main/java/io/druid/query/groupby/strategy/GroupByStrategyV2.java +++ b/processing/src/main/java/io/druid/query/groupby/strategy/GroupByStrategyV2.java @@ -145,6 +145,7 @@ protected BinaryFn createMergeFn(Query queryParam) new GroupByQuery( query.getDataSource(), query.getQuerySegmentSpec(), + query.getVirtualColumns(), query.getDimFilter(), query.getGranularity(), query.getDimensions(), diff --git a/processing/src/main/java/io/druid/query/metadata/SegmentAnalyzer.java b/processing/src/main/java/io/druid/query/metadata/SegmentAnalyzer.java index 603f8c8e99f9..4e038e4ba01e 100644 --- a/processing/src/main/java/io/druid/query/metadata/SegmentAnalyzer.java +++ b/processing/src/main/java/io/druid/query/metadata/SegmentAnalyzer.java @@ -39,7 +39,6 @@ import io.druid.segment.QueryableIndex; import io.druid.segment.Segment; import io.druid.segment.StorageAdapter; -import io.druid.segment.VirtualColumns; import io.druid.segment.column.BitmapIndex; import io.druid.segment.column.Column; import io.druid.segment.column.ColumnCapabilities; @@ -49,6 +48,7 @@ import io.druid.segment.data.IndexedInts; import io.druid.segment.serde.ComplexMetricSerde; import io.druid.segment.serde.ComplexMetrics; +import io.druid.segment.VirtualColumns; import org.joda.time.Interval; import javax.annotation.Nullable; diff --git a/processing/src/main/java/io/druid/query/search/SearchQueryRunner.java b/processing/src/main/java/io/druid/query/search/SearchQueryRunner.java index 9e6b7e85920d..954b4de49a97 100644 --- a/processing/src/main/java/io/druid/query/search/SearchQueryRunner.java +++ b/processing/src/main/java/io/druid/query/search/SearchQueryRunner.java @@ -25,10 +25,10 @@ import com.google.common.collect.Iterables; import com.google.common.collect.Lists; import com.google.common.collect.Maps; +import com.metamx.emitter.EmittingLogger; import io.druid.collections.bitmap.BitmapFactory; import io.druid.collections.bitmap.ImmutableBitmap; import io.druid.collections.bitmap.MutableBitmap; -import com.metamx.emitter.EmittingLogger; import io.druid.java.util.common.IAE; import io.druid.java.util.common.ISE; import io.druid.java.util.common.guava.Accumulator; @@ -52,12 +52,12 @@ import io.druid.segment.QueryableIndex; import io.druid.segment.Segment; import io.druid.segment.StorageAdapter; -import io.druid.segment.VirtualColumns; import io.druid.segment.column.BitmapIndex; import io.druid.segment.column.Column; import io.druid.segment.column.GenericColumn; import io.druid.segment.data.IndexedInts; import io.druid.segment.filter.Filters; +import io.druid.segment.VirtualColumns; import org.apache.commons.lang.mutable.MutableInt; import org.joda.time.Interval; diff --git a/processing/src/main/java/io/druid/query/select/SelectQuery.java b/processing/src/main/java/io/druid/query/select/SelectQuery.java index 4dd27a593083..d33ff67fe7d8 100644 --- a/processing/src/main/java/io/druid/query/select/SelectQuery.java +++ b/processing/src/main/java/io/druid/query/select/SelectQuery.java @@ -31,7 +31,7 @@ import io.druid.query.dimension.DimensionSpec; import io.druid.query.filter.DimFilter; import io.druid.query.spec.QuerySegmentSpec; -import io.druid.segment.VirtualColumn; +import io.druid.segment.VirtualColumns; import java.util.List; import java.util.Map; @@ -46,7 +46,7 @@ public class SelectQuery extends BaseQuery> private final QueryGranularity granularity; private final List dimensions; private final List metrics; - private final List virtualColumns; + private final VirtualColumns virtualColumns; private final PagingSpec pagingSpec; @JsonCreator @@ -58,7 +58,7 @@ public SelectQuery( @JsonProperty("granularity") QueryGranularity granularity, @JsonProperty("dimensions") List dimensions, @JsonProperty("metrics") List metrics, - @JsonProperty("virtualColumns") List virtualColumns, + @JsonProperty("virtualColumns") VirtualColumns virtualColumns, @JsonProperty("pagingSpec") PagingSpec pagingSpec, @JsonProperty("context") Map context ) @@ -67,7 +67,7 @@ public SelectQuery( this.dimFilter = dimFilter; this.granularity = granularity; this.dimensions = dimensions; - this.virtualColumns = virtualColumns; + this.virtualColumns = virtualColumns == null ? VirtualColumns.EMPTY : virtualColumns; this.metrics = metrics; this.pagingSpec = pagingSpec; @@ -134,7 +134,7 @@ public List getMetrics() } @JsonProperty - public List getVirtualColumns() + public VirtualColumns getVirtualColumns() { return virtualColumns; } diff --git a/processing/src/main/java/io/druid/query/select/SelectQueryEngine.java b/processing/src/main/java/io/druid/query/select/SelectQueryEngine.java index eb6786f9edbc..d47a71663db1 100644 --- a/processing/src/main/java/io/druid/query/select/SelectQueryEngine.java +++ b/processing/src/main/java/io/druid/query/select/SelectQueryEngine.java @@ -37,7 +37,6 @@ import io.druid.segment.ObjectColumnSelector; import io.druid.segment.Segment; import io.druid.segment.StorageAdapter; -import io.druid.segment.VirtualColumns; import io.druid.segment.column.Column; import io.druid.segment.data.IndexedInts; import io.druid.segment.filter.Filters; @@ -90,7 +89,7 @@ public Sequence> process(final SelectQuery query, fina adapter, query.getQuerySegmentSpec().getIntervals(), filter, - VirtualColumns.valueOf(query.getVirtualColumns()), + query.getVirtualColumns(), query.isDescending(), query.getGranularity(), new Function>() diff --git a/processing/src/main/java/io/druid/query/select/SelectQueryQueryToolChest.java b/processing/src/main/java/io/druid/query/select/SelectQueryQueryToolChest.java index 99ff72251fd4..2bb009835e2d 100644 --- a/processing/src/main/java/io/druid/query/select/SelectQueryQueryToolChest.java +++ b/processing/src/main/java/io/druid/query/select/SelectQueryQueryToolChest.java @@ -49,7 +49,6 @@ import io.druid.query.dimension.DimensionSpec; import io.druid.query.filter.DimFilter; import io.druid.timeline.DataSegmentUtils; -import io.druid.segment.VirtualColumn; import io.druid.timeline.LogicalSegment; import org.joda.time.DateTime; import org.joda.time.Interval; @@ -192,20 +191,7 @@ public byte[] computeCacheKey(SelectQuery query) ++index; } - List virtualColumns = query.getVirtualColumns(); - if (virtualColumns == null) { - virtualColumns = Collections.emptyList(); - } - - final byte[][] virtualColumnsBytes = new byte[virtualColumns.size()][]; - int virtualColumnsBytesSize = 0; - index = 0; - for (VirtualColumn vc : virtualColumns) { - virtualColumnsBytes[index] = vc.getCacheKey(); - virtualColumnsBytesSize += virtualColumnsBytes[index].length; - ++index; - } - + final byte[] virtualColumnsCacheKey = query.getVirtualColumns().getCacheKey(); final ByteBuffer queryCacheKey = ByteBuffer .allocate( 1 @@ -214,7 +200,7 @@ public byte[] computeCacheKey(SelectQuery query) + query.getPagingSpec().getCacheKey().length + dimensionsBytesSize + metricBytesSize - + virtualColumnsBytesSize + + virtualColumnsCacheKey.length ) .put(SELECT_QUERY) .put(granularityBytes) @@ -229,9 +215,7 @@ public byte[] computeCacheKey(SelectQuery query) queryCacheKey.put(metricByte); } - for (byte[] vcByte : virtualColumnsBytes) { - queryCacheKey.put(vcByte); - } + queryCacheKey.put(virtualColumnsCacheKey); return queryCacheKey.array(); } diff --git a/processing/src/main/java/io/druid/query/timeboundary/TimeBoundaryQueryRunnerFactory.java b/processing/src/main/java/io/druid/query/timeboundary/TimeBoundaryQueryRunnerFactory.java index 921e1c3a909b..9773a08852f8 100644 --- a/processing/src/main/java/io/druid/query/timeboundary/TimeBoundaryQueryRunnerFactory.java +++ b/processing/src/main/java/io/druid/query/timeboundary/TimeBoundaryQueryRunnerFactory.java @@ -39,9 +39,9 @@ import io.druid.segment.LongColumnSelector; import io.druid.segment.Segment; import io.druid.segment.StorageAdapter; -import io.druid.segment.VirtualColumns; import io.druid.segment.column.Column; import io.druid.segment.filter.Filters; +import io.druid.segment.VirtualColumns; import org.joda.time.DateTime; import java.util.Iterator; diff --git a/processing/src/main/java/io/druid/query/timeseries/TimeseriesQuery.java b/processing/src/main/java/io/druid/query/timeseries/TimeseriesQuery.java index 964bf38fb9d1..01f04638b687 100644 --- a/processing/src/main/java/io/druid/query/timeseries/TimeseriesQuery.java +++ b/processing/src/main/java/io/druid/query/timeseries/TimeseriesQuery.java @@ -33,6 +33,7 @@ import io.druid.query.aggregation.PostAggregator; import io.druid.query.filter.DimFilter; import io.druid.query.spec.QuerySegmentSpec; +import io.druid.segment.VirtualColumns; import java.util.List; import java.util.Map; @@ -42,6 +43,7 @@ @JsonTypeName("timeseries") public class TimeseriesQuery extends BaseQuery> { + private final VirtualColumns virtualColumns; private final DimFilter dimFilter; private final QueryGranularity granularity; private final List aggregatorSpecs; @@ -52,6 +54,7 @@ public TimeseriesQuery( @JsonProperty("dataSource") DataSource dataSource, @JsonProperty("intervals") QuerySegmentSpec querySegmentSpec, @JsonProperty("descending") boolean descending, + @JsonProperty("virtualColumns") VirtualColumns virtualColumns, @JsonProperty("filter") DimFilter dimFilter, @JsonProperty("granularity") QueryGranularity granularity, @JsonProperty("aggregations") List aggregatorSpecs, @@ -60,6 +63,7 @@ public TimeseriesQuery( ) { super(dataSource, querySegmentSpec, descending, context); + this.virtualColumns = virtualColumns == null ? VirtualColumns.EMPTY : virtualColumns; this.dimFilter = dimFilter; this.granularity = granularity; this.aggregatorSpecs = aggregatorSpecs == null ? ImmutableList.of() : aggregatorSpecs; @@ -86,6 +90,12 @@ public String getType() return Query.TIMESERIES; } + @JsonProperty + public VirtualColumns getVirtualColumns() + { + return virtualColumns; + } + @JsonProperty("filter") public DimFilter getDimensionsFilter() { @@ -121,6 +131,7 @@ public TimeseriesQuery withQuerySegmentSpec(QuerySegmentSpec querySegmentSpec) getDataSource(), querySegmentSpec, isDescending(), + virtualColumns, dimFilter, granularity, aggregatorSpecs, @@ -136,6 +147,7 @@ public Query> withDataSource(DataSource dataSource dataSource, getQuerySegmentSpec(), isDescending(), + virtualColumns, dimFilter, granularity, aggregatorSpecs, @@ -150,6 +162,7 @@ public TimeseriesQuery withOverriddenContext(Map contextOverride getDataSource(), getQuerySegmentSpec(), isDescending(), + virtualColumns, dimFilter, granularity, aggregatorSpecs, @@ -164,6 +177,7 @@ public TimeseriesQuery withDimFilter(DimFilter dimFilter) getDataSource(), getQuerySegmentSpec(), isDescending(), + virtualColumns, dimFilter, granularity, aggregatorSpecs, @@ -172,21 +186,6 @@ public TimeseriesQuery withDimFilter(DimFilter dimFilter) ); } - @Override - public String toString() - { - return "TimeseriesQuery{" + - "dataSource='" + getDataSource() + '\'' + - ", querySegmentSpec=" + getQuerySegmentSpec() + - ", descending=" + isDescending() + - ", dimFilter=" + dimFilter + - ", granularity='" + granularity + '\'' + - ", aggregatorSpecs=" + aggregatorSpecs + - ", postAggregatorSpecs=" + postAggregatorSpecs + - ", context=" + getContext() + - '}'; - } - @Override public boolean equals(Object o) { @@ -202,7 +201,7 @@ public boolean equals(Object o) TimeseriesQuery that = (TimeseriesQuery) o; - if (aggregatorSpecs != null ? !aggregatorSpecs.equals(that.aggregatorSpecs) : that.aggregatorSpecs != null) { + if (!virtualColumns.equals(that.virtualColumns)) { return false; } if (dimFilter != null ? !dimFilter.equals(that.dimFilter) : that.dimFilter != null) { @@ -211,21 +210,35 @@ public boolean equals(Object o) if (granularity != null ? !granularity.equals(that.granularity) : that.granularity != null) { return false; } - if (postAggregatorSpecs != null ? !postAggregatorSpecs.equals(that.postAggregatorSpecs) : that.postAggregatorSpecs != null) { + if (aggregatorSpecs != null ? !aggregatorSpecs.equals(that.aggregatorSpecs) : that.aggregatorSpecs != null) { return false; } - - return true; + return postAggregatorSpecs != null + ? postAggregatorSpecs.equals(that.postAggregatorSpecs) + : that.postAggregatorSpecs == null; } @Override public int hashCode() { int result = super.hashCode(); + result = 31 * result + virtualColumns.hashCode(); result = 31 * result + (dimFilter != null ? dimFilter.hashCode() : 0); result = 31 * result + (granularity != null ? granularity.hashCode() : 0); result = 31 * result + (aggregatorSpecs != null ? aggregatorSpecs.hashCode() : 0); result = 31 * result + (postAggregatorSpecs != null ? postAggregatorSpecs.hashCode() : 0); return result; } + + @Override + public String toString() + { + return "TimeseriesQuery{" + + "virtualColumns=" + virtualColumns + + ", dimFilter=" + dimFilter + + ", granularity=" + granularity + + ", aggregatorSpecs=" + aggregatorSpecs + + ", postAggregatorSpecs=" + postAggregatorSpecs + + '}'; + } } diff --git a/processing/src/main/java/io/druid/query/timeseries/TimeseriesQueryEngine.java b/processing/src/main/java/io/druid/query/timeseries/TimeseriesQueryEngine.java index 5ee286519cc5..bbe57f5df3d9 100644 --- a/processing/src/main/java/io/druid/query/timeseries/TimeseriesQueryEngine.java +++ b/processing/src/main/java/io/druid/query/timeseries/TimeseriesQueryEngine.java @@ -29,7 +29,6 @@ import io.druid.segment.Cursor; import io.druid.segment.SegmentMissingException; import io.druid.segment.StorageAdapter; -import io.druid.segment.VirtualColumns; import io.druid.segment.filter.Filters; import java.util.List; @@ -52,7 +51,7 @@ public Sequence> process(final TimeseriesQuery que adapter, query.getQuerySegmentSpec().getIntervals(), filter, - VirtualColumns.EMPTY, + query.getVirtualColumns(), query.isDescending(), query.getGranularity(), new Function>() diff --git a/processing/src/main/java/io/druid/query/timeseries/TimeseriesQueryQueryToolChest.java b/processing/src/main/java/io/druid/query/timeseries/TimeseriesQueryQueryToolChest.java index 090220e11e9e..3aa737821890 100644 --- a/processing/src/main/java/io/druid/query/timeseries/TimeseriesQueryQueryToolChest.java +++ b/processing/src/main/java/io/druid/query/timeseries/TimeseriesQueryQueryToolChest.java @@ -138,15 +138,23 @@ public byte[] computeCacheKey(TimeseriesQuery query) final byte[] granularityBytes = query.getGranularity().cacheKey(); final byte descending = query.isDescending() ? (byte) 1 : 0; final byte skipEmptyBuckets = query.isSkipEmptyBuckets() ? (byte) 1 : 0; + final byte[] virtualColumnsBytes = query.getVirtualColumns().getCacheKey(); return ByteBuffer - .allocate(3 + granularityBytes.length + filterBytes.length + aggregatorBytes.length) + .allocate( + 3 + + granularityBytes.length + + filterBytes.length + + aggregatorBytes.length + + virtualColumnsBytes.length + ) .put(TIMESERIES_QUERY) .put(descending) .put(skipEmptyBuckets) .put(granularityBytes) .put(filterBytes) .put(aggregatorBytes) + .put(virtualColumnsBytes) .array(); } diff --git a/processing/src/main/java/io/druid/query/topn/AggregateTopNMetricFirstAlgorithm.java b/processing/src/main/java/io/druid/query/topn/AggregateTopNMetricFirstAlgorithm.java index 3a7d16e51a63..644ddaf683a5 100644 --- a/processing/src/main/java/io/druid/query/topn/AggregateTopNMetricFirstAlgorithm.java +++ b/processing/src/main/java/io/druid/query/topn/AggregateTopNMetricFirstAlgorithm.java @@ -81,10 +81,10 @@ public void run( throw new ISE("WTF! Can't find the metric to do topN over?"); } // Run topN for only a single metric - TopNQuery singleMetricQuery = new TopNQueryBuilder().copy(query) - .aggregators(condensedAggPostAggPair.lhs) - .postAggregators(condensedAggPostAggPair.rhs) - .build(); + TopNQuery singleMetricQuery = new TopNQueryBuilder(query) + .aggregators(condensedAggPostAggPair.lhs) + .postAggregators(condensedAggPostAggPair.rhs) + .build(); final TopNResultBuilder singleMetricResultBuilder = BaseTopNAlgorithm.makeResultBuilder(params, singleMetricQuery); PooledTopNAlgorithm singleMetricAlgo = new PooledTopNAlgorithm(capabilities, singleMetricQuery, bufferPool); diff --git a/processing/src/main/java/io/druid/query/topn/TopNQuery.java b/processing/src/main/java/io/druid/query/topn/TopNQuery.java index 2221e65d4863..e0991425b46d 100644 --- a/processing/src/main/java/io/druid/query/topn/TopNQuery.java +++ b/processing/src/main/java/io/druid/query/topn/TopNQuery.java @@ -34,6 +34,7 @@ import io.druid.query.dimension.DimensionSpec; import io.druid.query.filter.DimFilter; import io.druid.query.spec.QuerySegmentSpec; +import io.druid.segment.VirtualColumns; import java.util.List; import java.util.Map; @@ -44,6 +45,7 @@ public class TopNQuery extends BaseQuery> { public static final String TOPN = "topN"; + private final VirtualColumns virtualColumns; private final DimensionSpec dimensionSpec; private final TopNMetricSpec topNMetricSpec; private final int threshold; @@ -55,6 +57,7 @@ public class TopNQuery extends BaseQuery> @JsonCreator public TopNQuery( @JsonProperty("dataSource") DataSource dataSource, + @JsonProperty("virtualColumns") VirtualColumns virtualColumns, @JsonProperty("dimension") DimensionSpec dimensionSpec, @JsonProperty("metric") TopNMetricSpec topNMetricSpec, @JsonProperty("threshold") int threshold, @@ -67,6 +70,7 @@ public TopNQuery( ) { super(dataSource, querySegmentSpec, false, context); + this.virtualColumns = virtualColumns == null ? VirtualColumns.EMPTY : virtualColumns; this.dimensionSpec = dimensionSpec; this.topNMetricSpec = topNMetricSpec; this.threshold = threshold; @@ -103,6 +107,12 @@ public String getType() return TOPN; } + @JsonProperty + public VirtualColumns getVirtualColumns() + { + return virtualColumns; + } + @JsonProperty("dimension") public DimensionSpec getDimensionSpec() { @@ -157,6 +167,7 @@ public TopNQuery withQuerySegmentSpec(QuerySegmentSpec querySegmentSpec) { return new TopNQuery( getDataSource(), + virtualColumns, dimensionSpec, topNMetricSpec, threshold, @@ -173,6 +184,7 @@ public TopNQuery withDimensionSpec(DimensionSpec spec) { return new TopNQuery( getDataSource(), + virtualColumns, spec, topNMetricSpec, threshold, @@ -189,6 +201,7 @@ public TopNQuery withAggregatorSpecs(List aggregatorSpecs) { return new TopNQuery( getDataSource(), + virtualColumns, getDimensionSpec(), topNMetricSpec, threshold, @@ -205,6 +218,7 @@ public TopNQuery withPostAggregatorSpecs(List postAggregatorSpec { return new TopNQuery( getDataSource(), + virtualColumns, getDimensionSpec(), topNMetricSpec, threshold, @@ -222,6 +236,7 @@ public Query> withDataSource(DataSource dataSource) { return new TopNQuery( dataSource, + virtualColumns, dimensionSpec, topNMetricSpec, threshold, @@ -238,6 +253,7 @@ public TopNQuery withThreshold(int threshold) { return new TopNQuery( getDataSource(), + virtualColumns, dimensionSpec, topNMetricSpec, threshold, @@ -254,6 +270,7 @@ public TopNQuery withOverriddenContext(Map contextOverrides) { return new TopNQuery( getDataSource(), + virtualColumns, dimensionSpec, topNMetricSpec, threshold, @@ -270,6 +287,7 @@ public TopNQuery withDimFilter(DimFilter dimFilter) { return new TopNQuery( getDataSource(), + virtualColumns, getDimensionSpec(), topNMetricSpec, threshold, @@ -282,22 +300,6 @@ public TopNQuery withDimFilter(DimFilter dimFilter) ); } - @Override - public String toString() - { - return "TopNQuery{" + - "dataSource='" + getDataSource() + '\'' + - ", dimensionSpec=" + dimensionSpec + - ", topNMetricSpec=" + topNMetricSpec + - ", threshold=" + threshold + - ", querySegmentSpec=" + getQuerySegmentSpec() + - ", dimFilter=" + dimFilter + - ", granularity='" + granularity + '\'' + - ", aggregatorSpecs=" + aggregatorSpecs + - ", postAggregatorSpecs=" + postAggregatorSpecs + - '}'; - } - @Override public boolean equals(Object o) { @@ -311,37 +313,39 @@ public boolean equals(Object o) return false; } - TopNQuery topNQuery = (TopNQuery) o; + TopNQuery query = (TopNQuery) o; - if (threshold != topNQuery.threshold) { + if (threshold != query.threshold) { return false; } - if (aggregatorSpecs != null ? !aggregatorSpecs.equals(topNQuery.aggregatorSpecs) : topNQuery.aggregatorSpecs != null) { + if (!virtualColumns.equals(query.virtualColumns)) { return false; } - if (dimFilter != null ? !dimFilter.equals(topNQuery.dimFilter) : topNQuery.dimFilter != null) { + if (dimensionSpec != null ? !dimensionSpec.equals(query.dimensionSpec) : query.dimensionSpec != null) { return false; } - if (dimensionSpec != null ? !dimensionSpec.equals(topNQuery.dimensionSpec) : topNQuery.dimensionSpec != null) { + if (topNMetricSpec != null ? !topNMetricSpec.equals(query.topNMetricSpec) : query.topNMetricSpec != null) { return false; } - if (granularity != null ? !granularity.equals(topNQuery.granularity) : topNQuery.granularity != null) { + if (dimFilter != null ? !dimFilter.equals(query.dimFilter) : query.dimFilter != null) { return false; } - if (postAggregatorSpecs != null ? !postAggregatorSpecs.equals(topNQuery.postAggregatorSpecs) : topNQuery.postAggregatorSpecs != null) { + if (granularity != null ? !granularity.equals(query.granularity) : query.granularity != null) { return false; } - if (topNMetricSpec != null ? !topNMetricSpec.equals(topNQuery.topNMetricSpec) : topNQuery.topNMetricSpec != null) { + if (aggregatorSpecs != null ? !aggregatorSpecs.equals(query.aggregatorSpecs) : query.aggregatorSpecs != null) { return false; } - - return true; + return postAggregatorSpecs != null + ? postAggregatorSpecs.equals(query.postAggregatorSpecs) + : query.postAggregatorSpecs == null; } @Override public int hashCode() { int result = super.hashCode(); + result = 31 * result + virtualColumns.hashCode(); result = 31 * result + (dimensionSpec != null ? dimensionSpec.hashCode() : 0); result = 31 * result + (topNMetricSpec != null ? topNMetricSpec.hashCode() : 0); result = 31 * result + threshold; @@ -351,4 +355,19 @@ public int hashCode() result = 31 * result + (postAggregatorSpecs != null ? postAggregatorSpecs.hashCode() : 0); return result; } + + @Override + public String toString() + { + return "TopNQuery{" + + "virtualColumns=" + virtualColumns + + ", dimensionSpec=" + dimensionSpec + + ", topNMetricSpec=" + topNMetricSpec + + ", threshold=" + threshold + + ", dimFilter=" + dimFilter + + ", granularity=" + granularity + + ", aggregatorSpecs=" + aggregatorSpecs + + ", postAggregatorSpecs=" + postAggregatorSpecs + + '}'; + } } diff --git a/processing/src/main/java/io/druid/query/topn/TopNQueryBuilder.java b/processing/src/main/java/io/druid/query/topn/TopNQueryBuilder.java index bdd09b95353d..dfe68b262361 100644 --- a/processing/src/main/java/io/druid/query/topn/TopNQueryBuilder.java +++ b/processing/src/main/java/io/druid/query/topn/TopNQueryBuilder.java @@ -33,19 +33,22 @@ import io.druid.query.filter.SelectorDimFilter; import io.druid.query.spec.LegacySegmentSpec; import io.druid.query.spec.QuerySegmentSpec; +import io.druid.segment.VirtualColumn; +import io.druid.segment.VirtualColumns; import org.joda.time.Interval; +import java.util.Arrays; import java.util.List; import java.util.Map; /** * A Builder for TopNQuery. - * + * * Required: dataSource(), intervals(), metric() and threshold() must be called before build() * Additional requirement for numeric metric sorts: aggregators() must be called before build() - * + * * Optional: filters(), granularity(), postAggregators() and context() can be called before build() - * + * * Usage example: * 

  *   TopNQuery query = new TopNQueryBuilder()
@@ -62,6 +65,7 @@
 public class TopNQueryBuilder
 {
   private DataSource dataSource;
+  private VirtualColumns virtualColumns;
   private DimensionSpec dimensionSpec;
   private TopNMetricSpec topNMetricSpec;
   private int threshold;
@@ -75,6 +79,7 @@ public class TopNQueryBuilder
   public TopNQueryBuilder()
   {
     dataSource = null;
+    virtualColumns = null;
     dimensionSpec = null;
     topNMetricSpec = null;
     threshold = 0;
@@ -86,11 +91,31 @@ public TopNQueryBuilder()
     context = null;
   }
 
+  public TopNQueryBuilder(final TopNQuery query)
+  {
+      this.dataSource = query.getDataSource();
+      this.virtualColumns = query.getVirtualColumns();
+      this.dimensionSpec = query.getDimensionSpec();
+      this.topNMetricSpec = query.getTopNMetricSpec();
+      this.threshold = query.getThreshold();
+      this.querySegmentSpec = query.getQuerySegmentSpec();
+      this.dimFilter = query.getDimensionsFilter();
+      this.granularity = query.getGranularity();
+      this.aggregatorSpecs = query.getAggregatorSpecs();
+      this.postAggregatorSpecs = query.getPostAggregatorSpecs();
+      this.context = query.getContext();
+  }
+
   public DataSource getDataSource()
   {
     return dataSource;
   }
 
+  public VirtualColumns getVirtualColumns()
+  {
+    return virtualColumns;
+  }
+
   public DimensionSpec getDimensionSpec()
   {
     return dimensionSpec;
@@ -140,6 +165,7 @@ public TopNQuery build()
   {
     return new TopNQuery(
         dataSource,
+        virtualColumns,
         dimensionSpec,
         topNMetricSpec,
         threshold,
@@ -152,25 +178,18 @@ public TopNQuery build()
     );
   }
 
+  @Deprecated
   public TopNQueryBuilder copy(TopNQuery query)
   {
-    return new TopNQueryBuilder()
-        .dataSource(query.getDataSource().toString())
-        .dimension(query.getDimensionSpec())
-        .metric(query.getTopNMetricSpec())
-        .threshold(query.getThreshold())
-        .intervals(query.getIntervals())
-        .filters(query.getDimensionsFilter())
-        .granularity(query.getGranularity())
-        .aggregators(query.getAggregatorSpecs())
-        .postAggregators(query.getPostAggregatorSpecs())
-        .context(query.getContext());
+    return new TopNQueryBuilder(query);
   }
 
+  @Deprecated
   public TopNQueryBuilder copy(TopNQueryBuilder builder)
   {
     return new TopNQueryBuilder()
         .dataSource(builder.dataSource)
+        .virtualColumns(builder.virtualColumns)
         .dimension(builder.dimensionSpec)
         .metric(builder.topNMetricSpec)
         .threshold(builder.threshold)
@@ -188,6 +207,22 @@ public TopNQueryBuilder dataSource(String d)
     return this;
   }
 
+  public TopNQueryBuilder virtualColumns(VirtualColumns virtualColumns)
+  {
+    this.virtualColumns = virtualColumns;
+    return this;
+  }
+
+  public TopNQueryBuilder virtualColumns(List virtualColumns)
+  {
+    return virtualColumns(VirtualColumns.create(virtualColumns));
+  }
+
+  public TopNQueryBuilder virtualColumns(VirtualColumn... virtualColumns)
+  {
+    return virtualColumns(VirtualColumns.create(Arrays.asList(virtualColumns)));
+  }
+
   public TopNQueryBuilder dataSource(DataSource d)
   {
     dataSource = d;
diff --git a/processing/src/main/java/io/druid/query/topn/TopNQueryEngine.java b/processing/src/main/java/io/druid/query/topn/TopNQueryEngine.java
index bb4e121f6e61..e1467da10494 100644
--- a/processing/src/main/java/io/druid/query/topn/TopNQueryEngine.java
+++ b/processing/src/main/java/io/druid/query/topn/TopNQueryEngine.java
@@ -35,7 +35,6 @@
 import io.druid.segment.Cursor;
 import io.druid.segment.SegmentMissingException;
 import io.druid.segment.StorageAdapter;
-import io.druid.segment.VirtualColumns;
 import io.druid.segment.column.Column;
 import io.druid.segment.filter.Filters;
 import org.joda.time.Interval;
@@ -75,7 +74,13 @@ public Sequence> query(final TopNQuery query, final Stor
 
     return Sequences.filter(
         Sequences.map(
-            adapter.makeCursors(filter, queryIntervals.get(0), VirtualColumns.EMPTY, granularity, query.isDescending()),
+            adapter.makeCursors(
+                filter,
+                queryIntervals.get(0),
+                query.getVirtualColumns(),
+                granularity,
+                query.isDescending()
+            ),
             new Function>()
             {
               @Override
diff --git a/processing/src/main/java/io/druid/query/topn/TopNQueryQueryToolChest.java b/processing/src/main/java/io/druid/query/topn/TopNQueryQueryToolChest.java
index 052f14710d5c..8a1104470398 100644
--- a/processing/src/main/java/io/druid/query/topn/TopNQueryQueryToolChest.java
+++ b/processing/src/main/java/io/druid/query/topn/TopNQueryQueryToolChest.java
@@ -313,11 +313,13 @@ public byte[] computeCacheKey(TopNQuery query)
         final byte[] filterBytes = dimFilter == null ? new byte[]{} : dimFilter.getCacheKey();
         final byte[] aggregatorBytes = QueryCacheHelper.computeAggregatorBytes(query.getAggregatorSpecs());
         final byte[] granularityBytes = query.getGranularity().cacheKey();
+        final byte[] virtualColumnBytes = query.getVirtualColumns().getCacheKey();
 
         return ByteBuffer
             .allocate(
-                1 + dimensionSpecBytes.length + metricSpecBytes.length + 4 +
-                granularityBytes.length + filterBytes.length + aggregatorBytes.length
+                1 + dimensionSpecBytes.length + metricSpecBytes.length + 4
+                + granularityBytes.length + filterBytes.length + aggregatorBytes.length
+                + virtualColumnBytes.length
             )
             .put(TOPN_QUERY)
             .put(dimensionSpecBytes)
@@ -326,6 +328,7 @@ public byte[] computeCacheKey(TopNQuery query)
             .put(granularityBytes)
             .put(filterBytes)
             .put(aggregatorBytes)
+            .put(virtualColumnBytes)
             .array();
       }
 
diff --git a/processing/src/main/java/io/druid/segment/ColumnSelectorFactory.java b/processing/src/main/java/io/druid/segment/ColumnSelectorFactory.java
index afb38476c048..5dcc6a97c868 100644
--- a/processing/src/main/java/io/druid/segment/ColumnSelectorFactory.java
+++ b/processing/src/main/java/io/druid/segment/ColumnSelectorFactory.java
@@ -20,17 +20,25 @@
 package io.druid.segment;
 
 import io.druid.query.dimension.DimensionSpec;
-import io.druid.segment.column.ColumnCapabilities;
+import io.druid.segment.column.ValueType;
 
 /**
  * Factory class for MetricSelectors
  */
 public interface ColumnSelectorFactory
 {
-  public DimensionSelector makeDimensionSelector(DimensionSpec dimensionSpec);
-  public FloatColumnSelector makeFloatColumnSelector(String columnName);
-  public LongColumnSelector makeLongColumnSelector(String columnName);
-  public ObjectColumnSelector makeObjectColumnSelector(String columnName);
-  public NumericColumnSelector makeMathExpressionSelector(String expression);
-  public ColumnCapabilities getColumnCapabilities(String columnName);
+  DimensionSelector makeDimensionSelector(DimensionSpec dimensionSpec);
+  FloatColumnSelector makeFloatColumnSelector(String columnName);
+  LongColumnSelector makeLongColumnSelector(String columnName);
+  ObjectColumnSelector makeObjectColumnSelector(String columnName);
+
+  /**
+   * Returns the native type of the named column, which should match the type returned, which
+   * should correspond to the best performing selector. May be null if unknown.
+   *
+   * @param columnName name of the column
+   *
+   * @return native type, or null if unknown
+   */
+  ValueType getNativeType(String columnName);
 }
diff --git a/processing/src/main/java/io/druid/segment/NullDimensionSelector.java b/processing/src/main/java/io/druid/segment/NullDimensionSelector.java
index f771afe408e1..620166f32eb1 100644
--- a/processing/src/main/java/io/druid/segment/NullDimensionSelector.java
+++ b/processing/src/main/java/io/druid/segment/NullDimensionSelector.java
@@ -28,20 +28,34 @@
 
 public class NullDimensionSelector implements DimensionSelector
 {
+  private static final NullDimensionSelector INSTANCE = new NullDimensionSelector();
 
-  private static final IndexedInts SINGLETON = new IndexedInts() {
+  private NullDimensionSelector()
+  {
+  }
+
+  public static final NullDimensionSelector instance()
+  {
+    return INSTANCE;
+  }
+
+  private static final IndexedInts SINGLETON = new IndexedInts()
+  {
     @Override
-    public int size() {
+    public int size()
+    {
       return 1;
     }
 
     @Override
-    public int get(int index) {
+    public int get(int index)
+    {
       return 0;
     }
 
     @Override
-    public IntIterator iterator() {
+    public IntIterator iterator()
+    {
       return IntIterators.singleton(0);
     }
 
diff --git a/processing/src/main/java/io/druid/segment/QueryableIndexStorageAdapter.java b/processing/src/main/java/io/druid/segment/QueryableIndexStorageAdapter.java
index 9e3a04a017cf..ca54f8add4e3 100644
--- a/processing/src/main/java/io/druid/segment/QueryableIndexStorageAdapter.java
+++ b/processing/src/main/java/io/druid/segment/QueryableIndexStorageAdapter.java
@@ -23,19 +23,15 @@
 import com.google.common.base.Predicate;
 import com.google.common.base.Predicates;
 import com.google.common.base.Strings;
-import com.google.common.base.Supplier;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import com.google.common.collect.Sets;
 import com.google.common.io.Closer;
-
 import io.druid.collections.bitmap.ImmutableBitmap;
 import io.druid.granularity.QueryGranularity;
 import io.druid.java.util.common.guava.Sequence;
 import io.druid.java.util.common.guava.Sequences;
-import io.druid.math.expr.Expr;
-import io.druid.math.expr.Parser;
 import io.druid.query.QueryInterruptedException;
 import io.druid.query.dimension.DefaultDimensionSpec;
 import io.druid.query.dimension.DimensionSpec;
@@ -50,7 +46,6 @@
 import io.druid.segment.column.BitmapIndex;
 import io.druid.segment.column.Column;
 import io.druid.segment.column.ColumnCapabilities;
-import io.druid.segment.column.ColumnCapabilitiesImpl;
 import io.druid.segment.column.ComplexColumn;
 import io.druid.segment.column.DictionaryEncodedColumn;
 import io.druid.segment.column.GenericColumn;
@@ -76,8 +71,6 @@
  */
 public class QueryableIndexStorageAdapter implements StorageAdapter
 {
-  private static final NullDimensionSelector NULL_DIMENSION_SELECTOR = new NullDimensionSelector();
-
   private final QueryableIndex index;
 
   public QueryableIndexStorageAdapter(
@@ -436,6 +429,10 @@ public DimensionSelector makeDimensionSelector(
                         DimensionSpec dimensionSpec
                     )
                     {
+                      if (virtualColumns.exists(dimensionSpec.getDimension())) {
+                        return virtualColumns.makeDimensionSelector(dimensionSpec, this);
+                      }
+
                       return dimensionSpec.decorate(makeDimensionSelectorUndecorated(dimensionSpec));
                     }
 
@@ -448,7 +445,7 @@ private DimensionSelector makeDimensionSelectorUndecorated(
 
                       final Column columnDesc = index.getColumn(dimension);
                       if (columnDesc == null) {
-                        return NULL_DIMENSION_SELECTOR;
+                        return NullDimensionSelector.instance();
                       }
 
                       if (dimension.equals(Column.TIME_COLUMN_NAME)) {
@@ -469,7 +466,7 @@ private DimensionSelector makeDimensionSelectorUndecorated(
                       final DictionaryEncodedColumn column = cachedColumn;
 
                       if (column == null) {
-                        return NULL_DIMENSION_SELECTOR;
+                        return NullDimensionSelector.instance();
                       } else if (columnDesc.getCapabilities().hasMultipleValues()) {
                         return new DimensionSelector()
                         {
@@ -577,6 +574,10 @@ public int lookupId(String name)
                     @Override
                     public FloatColumnSelector makeFloatColumnSelector(String columnName)
                     {
+                      if (virtualColumns.exists(columnName)) {
+                        return virtualColumns.makeFloatColumnSelector(columnName, this);
+                      }
+
                       GenericColumn cachedMetricVals = genericColumnCache.get(columnName);
 
                       if (cachedMetricVals == null) {
@@ -590,14 +591,7 @@ public FloatColumnSelector makeFloatColumnSelector(String columnName)
                       }
 
                       if (cachedMetricVals == null) {
-                        return new FloatColumnSelector()
-                        {
-                          @Override
-                          public float get()
-                          {
-                            return 0.0f;
-                          }
-                        };
+                        return ZeroFloatColumnSelector.instance();
                       }
 
                       final GenericColumn metricVals = cachedMetricVals;
@@ -614,6 +608,10 @@ public float get()
                     @Override
                     public LongColumnSelector makeLongColumnSelector(String columnName)
                     {
+                      if (virtualColumns.exists(columnName)) {
+                        return virtualColumns.makeLongColumnSelector(columnName, this);
+                      }
+
                       GenericColumn cachedMetricVals = genericColumnCache.get(columnName);
 
                       if (cachedMetricVals == null) {
@@ -627,14 +625,7 @@ public LongColumnSelector makeLongColumnSelector(String columnName)
                       }
 
                       if (cachedMetricVals == null) {
-                        return new LongColumnSelector()
-                        {
-                          @Override
-                          public long get()
-                          {
-                            return 0L;
-                          }
-                        };
+                        return ZeroLongColumnSelector.instance();
                       }
 
                       final GenericColumn metricVals = cachedMetricVals;
@@ -652,6 +643,10 @@ public long get()
                     @Override
                     public ObjectColumnSelector makeObjectColumnSelector(String column)
                     {
+                      if (virtualColumns.exists(column)) {
+                        return virtualColumns.makeObjectColumnSelector(column, this);
+                      }
+
                       Object cachedColumnVals = objectColumnCache.get(column);
 
                       if (cachedColumnVals == null) {
@@ -676,10 +671,6 @@ public ObjectColumnSelector makeObjectColumnSelector(String column)
                       }
 
                       if (cachedColumnVals == null) {
-                        VirtualColumn vc = virtualColumns.getVirtualColumn(column);
-                        if (vc != null) {
-                          return vc.init(column, this);
-                        }
                         return null;
                       }
 
@@ -807,72 +798,10 @@ public Object get()
                     }
 
                     @Override
-                    public NumericColumnSelector makeMathExpressionSelector(String expression)
-                    {
-                      final Expr parsed = Parser.parse(expression);
-                      final List required = Parser.findRequiredBindings(parsed);
-
-                      final Map> values = Maps.newHashMapWithExpectedSize(required.size());
-                      for (String columnName : index.getColumnNames()) {
-                        if (!required.contains(columnName)) {
-                          continue;
-                        }
-                        final GenericColumn column = index.getColumn(columnName).getGenericColumn();
-                        if (column == null) {
-                          continue;
-                        }
-                        closer.register(column);
-                        if (column.getType() == ValueType.FLOAT) {
-                          values.put(
-                              columnName, new Supplier()
-                              {
-                                @Override
-                                public Number get()
-                                {
-                                  return column.getFloatSingleValueRow(cursorOffset.getOffset());
-                                }
-                              }
-                          );
-                        } else if (column.getType() == ValueType.LONG) {
-                          values.put(
-                              columnName, new Supplier()
-                              {
-                                @Override
-                                public Number get()
-                                {
-                                  return column.getLongSingleValueRow(cursorOffset.getOffset());
-                                }
-                              }
-                          );
-                        } else {
-                          throw new UnsupportedOperationException(
-                              "Not supported type " + column.getType() + " for column " + columnName
-                          );
-                        }
-                      }
-                      final Expr.ObjectBinding binding = Parser.withSuppliers(values);
-                      return new NumericColumnSelector()
-                      {
-                        @Override
-                        public Number get()
-                        {
-                          return parsed.eval(binding).numericValue();
-                        }
-                      };
-                    }
-
-                    @Override
-                    public ColumnCapabilities getColumnCapabilities(String columnName)
+                    public ValueType getNativeType(String columnName)
                     {
-                      ColumnCapabilities capabilities = getColumnCapabilites(index, columnName);
-                      if (capabilities == null && !virtualColumns.isEmpty()) {
-                        VirtualColumn virtualColumn = virtualColumns.getVirtualColumn(columnName);
-                        if (virtualColumn != null) {
-                          Class clazz = virtualColumn.init(columnName, this).classOfObject();
-                          capabilities = new ColumnCapabilitiesImpl().setType(ValueType.typeFor(clazz));
-                        }
-                      }
-                      return capabilities;
+                      final ColumnCapabilities capabilities = getColumnCapabilites(index, columnName);
+                      return capabilities != null ? capabilities.getType() : virtualColumns.getNativeType(columnName);
                     }
                   }
 
@@ -1054,7 +983,7 @@ public CursorOffsetHolderValueMatcherFactory(
     @Override
     public ValueMatcher makeValueMatcher(String dimension, final String value)
     {
-      if (getTypeForDimension(dimension) == ValueType.LONG) {
+      if (cursor.getNativeType(dimension) == ValueType.LONG) {
         return Filters.getLongValueMatcher(
             cursor.makeLongColumnSelector(dimension),
             value
@@ -1095,14 +1024,13 @@ public boolean matches()
     @Override
     public ValueMatcher makeValueMatcher(String dimension, final DruidPredicateFactory predicateFactory)
     {
-      ValueType type = getTypeForDimension(dimension);
-      switch (type) {
-        case LONG:
-          return makeLongValueMatcher(dimension, predicateFactory.makeLongPredicate());
-        case STRING:
-          return makeStringValueMatcher(dimension, predicateFactory.makeStringPredicate());
-        default:
-          return new BooleanValueMatcher(predicateFactory.makeStringPredicate().apply(null));
+      final ValueType type = cursor.getNativeType(dimension);
+      if (type == ValueType.LONG) {
+        return makeLongValueMatcher(dimension, predicateFactory.makeLongPredicate());
+      } else if (type == ValueType.STRING) {
+        return makeStringValueMatcher(dimension, predicateFactory.makeStringPredicate());
+      } else {
+        return new BooleanValueMatcher(predicateFactory.makeStringPredicate().apply(null));
       }
     }
 
@@ -1140,12 +1068,6 @@ private ValueMatcher makeLongValueMatcher(String dimension, final DruidLongPredi
           predicate
       );
     }
-
-    private ValueType getTypeForDimension(String dimension)
-    {
-      ColumnCapabilities capabilities = getColumnCapabilites(index, dimension);
-      return capabilities == null ? ValueType.STRING : capabilities.getType();
-    }
   }
 
   private static class CursorOffsetHolderRowOffsetMatcherFactory implements RowOffsetMatcherFactory
diff --git a/processing/src/main/java/io/druid/segment/VirtualColumn.java b/processing/src/main/java/io/druid/segment/VirtualColumn.java
index 855affe8bf4f..97160d99e9e1 100644
--- a/processing/src/main/java/io/druid/segment/VirtualColumn.java
+++ b/processing/src/main/java/io/druid/segment/VirtualColumn.java
@@ -19,15 +19,25 @@
 
 package io.druid.segment;
 
+import com.fasterxml.jackson.annotation.JsonSubTypes;
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
+import io.druid.query.dimension.DimensionSpec;
+import io.druid.segment.column.ValueType;
+import io.druid.segment.virtual.ExpressionVirtualColumn;
+
+import java.util.List;
 
-/**
- */
-@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property = "type")
 /**
  * Virtual columns are "views" created over a ColumnSelectorFactory. They can potentially draw from multiple
  * underlying columns, although they always present themselves as if they were a single column.
+ *
+ * A virtual column object will be shared amongst threads and must be thread safe. The selectors returned
+ * from the various makeXXXSelector methods need not be thread safe.
  */
+@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property = "type")
+@JsonSubTypes(value = {
+    @JsonSubTypes.Type(name = "expression", value = ExpressionVirtualColumn.class)
+})
 public interface VirtualColumn
 {
   /**
@@ -42,10 +52,70 @@ public interface VirtualColumn
    * virtual column was referenced with, which is useful if this column uses dot notation.
    *
    * @param columnName the name this virtual column was referenced with
-   * @param factory column selector factory
-   * @return the selector
+   * @param factory    column selector factory
+   *
+   * @return the selector, must not be null
+   */
+  ObjectColumnSelector makeObjectColumnSelector(String columnName, ColumnSelectorFactory factory);
+
+  /**
+   * Build a selector corresponding to this virtual column. Also provides the name that the
+   * virtual column was referenced with (through {@link DimensionSpec#getDimension()}, which
+   * is useful if this column uses dot notation. The virtual column is expected to apply any
+   * necessary decoration from the dimensionSpec.
+   *
+   * @param dimensionSpec the dimensionSpec this column was referenced with
+   * @param factory       column selector factory
+   *
+   * @return the selector, or null if we can't make a selector
+   */
+  DimensionSelector makeDimensionSelector(DimensionSpec dimensionSpec, ColumnSelectorFactory factory);
+
+  /**
+   * Build a selector corresponding to this virtual column. Also provides the name that the
+   * virtual column was referenced with, which is useful if this column uses dot notation.
+   *
+   * @param columnName the name this virtual column was referenced with
+   * @param factory    column selector factory
+   *
+   * @return the selector, or null if we can't make a selector
+   */
+  FloatColumnSelector makeFloatColumnSelector(String columnName, ColumnSelectorFactory factory);
+
+  /**
+   * Build a selector corresponding to this virtual column. Also provides the name that the
+   * virtual column was referenced with, which is useful if this column uses dot notation.
+   *
+   * @param columnName the name this virtual column was referenced with
+   * @param factory    column selector factory
+   *
+   * @return the selector, or null if we can't make a selector
+   */
+  LongColumnSelector makeLongColumnSelector(String columnName, ColumnSelectorFactory factory);
+
+  /**
+   * Returns the native type of this virtual column, which should match the type returned
+   * by "makeObjectColumnSelector" and should correspond to the best performing selector.
+   * May vary based on columnName if this column uses dot notation.
+   *
+   * @param columnName the name this virtual column was referenced with
+   *
+   * @return native type, must not be null
+   */
+  ValueType nativeType(String columnName);
+
+  /**
+   * Returns a list of columns that this virtual column will access. This may include the
+   * names of other virtual columns. May be empty if a virtual column doesn't access any
+   * underlying columns.
+   *
+   * Does not pass columnName because there is an assumption that the list of columns
+   * needed by a dot-notation supporting virtual column will not vary based on the
+   * columnName.
+   *
+   * @return column names
    */
-  ObjectColumnSelector init(String columnName, ColumnSelectorFactory factory);
+  List requiredColumns();
 
   /**
    * Indicates that this virtual column can be referenced with dot notation. For example,
diff --git a/processing/src/main/java/io/druid/segment/VirtualColumns.java b/processing/src/main/java/io/druid/segment/VirtualColumns.java
index 799a0ca366e7..0f3a9e6934c5 100644
--- a/processing/src/main/java/io/druid/segment/VirtualColumns.java
+++ b/processing/src/main/java/io/druid/segment/VirtualColumns.java
@@ -19,62 +19,250 @@
 
 package io.druid.segment;
 
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonValue;
+import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
+import com.google.common.primitives.Ints;
+import io.druid.java.util.common.IAE;
+import io.druid.java.util.common.Pair;
+import io.druid.query.dimension.DimensionSpec;
+import io.druid.segment.column.Column;
+import io.druid.segment.column.ValueType;
+import io.druid.segment.virtual.VirtualizedColumnSelectorFactory;
 
+import java.nio.ByteBuffer;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 /**
+ * Class allowing lookup and usage of virtual columns.
  */
 public class VirtualColumns
 {
   public static final VirtualColumns EMPTY = new VirtualColumns(
-      ImmutableMap.of(), ImmutableMap.of()
+      ImmutableList.of(),
+      ImmutableMap.of(),
+      ImmutableMap.of()
   );
 
-  public static VirtualColumns valueOf(List virtualColumns) {
+  /**
+   * Split a dot-style columnName into the "main" columnName and the subColumn name after the dot. Useful for
+   * columns that support dot notation.
+   *
+   * @param columnName columnName like "foo" or "foo.bar"
+   *
+   * @return pair of main column name (will not be null) and subColumn name (may be null)
+   */
+  public static Pair splitColumnName(String columnName)
+  {
+    final int i = columnName.indexOf('.');
+    if (i < 0) {
+      return Pair.of(columnName, null);
+    } else {
+      return Pair.of(columnName.substring(0, i), columnName.substring(i + 1));
+    }
+  }
+
+  @JsonCreator
+  public static VirtualColumns create(List virtualColumns)
+  {
     if (virtualColumns == null || virtualColumns.isEmpty()) {
       return EMPTY;
     }
     Map withDotSupport = Maps.newHashMap();
     Map withoutDotSupport = Maps.newHashMap();
     for (VirtualColumn vc : virtualColumns) {
+      if (vc.getOutputName().equals(Column.TIME_COLUMN_NAME)) {
+        throw new IAE("virtualColumn name[%s] not allowed", vc.getOutputName());
+      }
+
+      if (withDotSupport.containsKey(vc.getOutputName()) || withoutDotSupport.containsKey(vc.getOutputName())) {
+        throw new IAE("Duplicate virtualColumn name[%s]", vc.getOutputName());
+      }
+
       if (vc.usesDotNotation()) {
         withDotSupport.put(vc.getOutputName(), vc);
       } else {
         withoutDotSupport.put(vc.getOutputName(), vc);
       }
     }
-    return new VirtualColumns(withDotSupport, withoutDotSupport);
+    return new VirtualColumns(ImmutableList.copyOf(virtualColumns), withDotSupport, withoutDotSupport);
   }
 
-  public VirtualColumns(Map withDotSupport, Map withoutDotSupport)
+  private VirtualColumns(
+      List virtualColumns,
+      Map withDotSupport,
+      Map withoutDotSupport
+  )
   {
+    this.virtualColumns = virtualColumns;
     this.withDotSupport = withDotSupport;
     this.withoutDotSupport = withoutDotSupport;
+
+    for (VirtualColumn virtualColumn : virtualColumns) {
+      detectCycles(virtualColumn, null);
+    }
   }
 
+  // For equals, hashCode, toString, and serialization:
+  private final List virtualColumns;
+
+  // For getVirtualColumn:
   private final Map withDotSupport;
   private final Map withoutDotSupport;
 
-  public VirtualColumn getVirtualColumn(String dimension)
+  public boolean exists(String columnName)
+  {
+    return getVirtualColumn(columnName) != null;
+  }
+
+  public VirtualColumn getVirtualColumn(String columnName)
   {
-    VirtualColumn vc = withoutDotSupport.get(dimension);
+    final VirtualColumn vc = withoutDotSupport.get(columnName);
     if (vc != null) {
       return vc;
     }
-    for (int index = dimension.indexOf('.'); index >= 0; index = dimension.indexOf('.', index + 1)) {
-      vc = withDotSupport.get(dimension.substring(0, index));
-      if (vc != null) {
-        return vc;
-      }
+    final String baseColumnName = splitColumnName(columnName).lhs;
+    return withDotSupport.get(baseColumnName);
+  }
+
+  public ObjectColumnSelector makeObjectColumnSelector(String columnName, ColumnSelectorFactory factory)
+  {
+    final VirtualColumn virtualColumn = getVirtualColumn(columnName);
+    if (virtualColumn == null) {
+      return null;
+    } else {
+      return Preconditions.checkNotNull(
+          virtualColumn.makeObjectColumnSelector(columnName, factory),
+          "VirtualColumn[%s] returned a null ObjectColumnSelector for columnName[%s]",
+          virtualColumn.getOutputName(),
+          columnName
+      );
+    }
+  }
+
+  public DimensionSelector makeDimensionSelector(DimensionSpec dimensionSpec, ColumnSelectorFactory factory)
+  {
+    final VirtualColumn virtualColumn = getVirtualColumn(dimensionSpec.getDimension());
+    if (virtualColumn == null) {
+      return dimensionSpec.decorate(NullDimensionSelector.instance());
+    } else {
+      final DimensionSelector selector = virtualColumn.makeDimensionSelector(dimensionSpec, factory);
+      return selector == null ? dimensionSpec.decorate(NullDimensionSelector.instance()) : selector;
+    }
+  }
+
+  public FloatColumnSelector makeFloatColumnSelector(String columnName, ColumnSelectorFactory factory)
+  {
+    final VirtualColumn virtualColumn = getVirtualColumn(columnName);
+    if (virtualColumn == null) {
+      return ZeroFloatColumnSelector.instance();
+    } else {
+      final FloatColumnSelector selector = virtualColumn.makeFloatColumnSelector(columnName, factory);
+      return selector == null ? ZeroFloatColumnSelector.instance() : selector;
+    }
+  }
+
+  public LongColumnSelector makeLongColumnSelector(String columnName, ColumnSelectorFactory factory)
+  {
+    final VirtualColumn virtualColumn = getVirtualColumn(columnName);
+    if (virtualColumn == null) {
+      return ZeroLongColumnSelector.instance();
+    } else {
+      final LongColumnSelector selector = virtualColumn.makeLongColumnSelector(columnName, factory);
+      return selector == null ? ZeroLongColumnSelector.instance() : selector;
     }
-    return withDotSupport.get(dimension);
+  }
+
+  public ValueType getNativeType(String columnName)
+  {
+    final VirtualColumn virtualColumn = getVirtualColumn(columnName);
+    return virtualColumn != null
+           ? Preconditions.checkNotNull(virtualColumn.nativeType(columnName), "nativeType for column[%s]", columnName)
+           : null;
   }
 
   public boolean isEmpty()
   {
     return withDotSupport.isEmpty() && withoutDotSupport.isEmpty();
   }
+
+  @JsonValue
+  public VirtualColumn[] getVirtualColumns()
+  {
+    // VirtualColumn[] instead of List to aid Jackson serialization.
+    return virtualColumns.toArray(new VirtualColumn[]{});
+  }
+
+  public ColumnSelectorFactory wrap(final ColumnSelectorFactory baseFactory)
+  {
+    return new VirtualizedColumnSelectorFactory(baseFactory, this);
+  }
+
+  public byte[] getCacheKey()
+  {
+    final byte[][] cacheKeys = new byte[virtualColumns.size()][];
+    int len = Ints.BYTES;
+    for (int i = 0; i < virtualColumns.size(); i++) {
+      cacheKeys[i] = virtualColumns.get(i).getCacheKey();
+      len += Ints.BYTES + cacheKeys[i].length;
+    }
+    final ByteBuffer buf = ByteBuffer.allocate(len).putInt(virtualColumns.size());
+    for (byte[] cacheKey : cacheKeys) {
+      buf.putInt(cacheKey.length);
+      buf.put(cacheKey);
+    }
+    return buf.array();
+  }
+
+  private void detectCycles(VirtualColumn virtualColumn, ImmutableSet columnNames)
+  {
+    Set nextSet = columnNames == null
+                          ? Sets.newHashSet(virtualColumn.getOutputName())
+                          : Sets.newHashSet(columnNames);
+
+    for (String columnName : virtualColumn.requiredColumns()) {
+      if (!nextSet.add(columnName)) {
+        throw new IAE("Self-referential column[%s]", columnName);
+      }
+
+      final VirtualColumn dependency = getVirtualColumn(columnName);
+      if (dependency != null) {
+        detectCycles(dependency, ImmutableSet.copyOf(nextSet));
+      }
+    }
+  }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+
+    VirtualColumns that = (VirtualColumns) o;
+
+    return virtualColumns.equals(that.virtualColumns);
+  }
+
+  @Override
+  public int hashCode()
+  {
+    return virtualColumns.hashCode();
+  }
+
+  @Override
+  public String toString()
+  {
+    return virtualColumns.toString();
+  }
 }
diff --git a/processing/src/main/java/io/druid/segment/ZeroFloatColumnSelector.java b/processing/src/main/java/io/druid/segment/ZeroFloatColumnSelector.java
new file mode 100644
index 000000000000..8e8eb99a4f8b
--- /dev/null
+++ b/processing/src/main/java/io/druid/segment/ZeroFloatColumnSelector.java
@@ -0,0 +1,41 @@
+/*
+ * Licensed to Metamarkets Group Inc. (Metamarkets) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. Metamarkets licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package io.druid.segment;
+
+public class ZeroFloatColumnSelector implements FloatColumnSelector
+{
+  private static final ZeroFloatColumnSelector INSTANCE = new ZeroFloatColumnSelector();
+
+  private ZeroFloatColumnSelector()
+  {
+    // No instantiation.
+  }
+
+  public static ZeroFloatColumnSelector instance()
+  {
+    return INSTANCE;
+  }
+
+  @Override
+  public float get()
+  {
+    return 0.0f;
+  }
+}
diff --git a/processing/src/main/java/io/druid/segment/ZeroLongColumnSelector.java b/processing/src/main/java/io/druid/segment/ZeroLongColumnSelector.java
new file mode 100644
index 000000000000..a24f16111c9f
--- /dev/null
+++ b/processing/src/main/java/io/druid/segment/ZeroLongColumnSelector.java
@@ -0,0 +1,41 @@
+/*
+ * Licensed to Metamarkets Group Inc. (Metamarkets) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. Metamarkets licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package io.druid.segment;
+
+public class ZeroLongColumnSelector implements LongColumnSelector
+{
+  private static final ZeroLongColumnSelector INSTANCE = new ZeroLongColumnSelector();
+
+  private ZeroLongColumnSelector()
+  {
+    // No instantiation.
+  }
+
+  public static ZeroLongColumnSelector instance()
+  {
+    return INSTANCE;
+  }
+
+  @Override
+  public long get()
+  {
+    return 0;
+  }
+}
diff --git a/processing/src/main/java/io/druid/segment/column/ValueType.java b/processing/src/main/java/io/druid/segment/column/ValueType.java
index 1760fea8c725..aa9919a129b9 100644
--- a/processing/src/main/java/io/druid/segment/column/ValueType.java
+++ b/processing/src/main/java/io/druid/segment/column/ValueType.java
@@ -26,17 +26,5 @@ public enum ValueType
   FLOAT,
   LONG,
   STRING,
-  COMPLEX;
-
-  public static ValueType typeFor(Class clazz)
-  {
-    if (clazz == String.class) {
-      return STRING;
-    } else if (clazz == float.class || clazz == Float.TYPE) {
-      return FLOAT;
-    } else if (clazz == long.class || clazz == Long.TYPE) {
-      return LONG;
-    }
-    return COMPLEX;
-  }
+  COMPLEX
 }
diff --git a/processing/src/main/java/io/druid/segment/incremental/IncrementalIndex.java b/processing/src/main/java/io/druid/segment/incremental/IncrementalIndex.java
index 6ec6db6d5f9e..0aef437c874e 100644
--- a/processing/src/main/java/io/druid/segment/incremental/IncrementalIndex.java
+++ b/processing/src/main/java/io/druid/segment/incremental/IncrementalIndex.java
@@ -38,9 +38,6 @@
 import io.druid.data.input.impl.DimensionsSpec;
 import io.druid.data.input.impl.SpatialDimensionSchema;
 import io.druid.granularity.QueryGranularity;
-import io.druid.math.expr.Evals;
-import io.druid.math.expr.Expr;
-import io.druid.math.expr.Parser;
 import io.druid.java.util.common.IAE;
 import io.druid.java.util.common.ISE;
 import io.druid.query.aggregation.AggregatorFactory;
@@ -55,7 +52,6 @@
 import io.druid.segment.FloatColumnSelector;
 import io.druid.segment.LongColumnSelector;
 import io.druid.segment.Metadata;
-import io.druid.segment.NumericColumnSelector;
 import io.druid.segment.ObjectColumnSelector;
 import io.druid.segment.column.Column;
 import io.druid.segment.column.ColumnCapabilities;
@@ -65,6 +61,7 @@
 import io.druid.segment.serde.ComplexMetricExtractor;
 import io.druid.segment.serde.ComplexMetricSerde;
 import io.druid.segment.serde.ComplexMetrics;
+import io.druid.segment.VirtualColumns;
 import it.unimi.dsi.fastutil.ints.IntIterator;
 import it.unimi.dsi.fastutil.ints.IntIterators;
 import org.joda.time.DateTime;
@@ -108,14 +105,23 @@ public abstract class IncrementalIndex implements Iterable,
       .put(DimensionSchema.ValueType.STRING, ValueType.STRING)
       .build();
 
+  /**
+   * Column selector used at ingestion time for inputs to aggregators.
+   *
+   * @param agg                       the aggregator
+   * @param in                        ingestion-time input row supplier
+   * @param deserializeComplexMetrics whether complex objects should be deserialized by a {@link ComplexMetricExtractor}
+   *
+   * @return column selector factory
+   */
   public static ColumnSelectorFactory makeColumnSelectorFactory(
+      final VirtualColumns virtualColumns,
       final AggregatorFactory agg,
       final Supplier in,
-      final boolean deserializeComplexMetrics,
-      final Map columnCapabilities
+      final boolean deserializeComplexMetrics
   )
   {
-    return new ColumnSelectorFactory()
+    final ColumnSelectorFactory baseFactory = new ColumnSelectorFactory()
     {
       @Override
       public LongColumnSelector makeLongColumnSelector(final String columnName)
@@ -201,13 +207,17 @@ public Object get()
       }
 
       @Override
-      public ColumnCapabilities getColumnCapabilities(String columnName)
+      public ValueType getNativeType(String columnName)
       {
-        // This ColumnSelectorFactory implementation has no knowledge of column capabilities.
-        // However, this method may still be called by FilteredAggregatorFactory's ValueMatcherFactory
-        // to check column types.
-        // Just return null, the caller will assume default types in that case.
-        return null;
+        // This ColumnSelectorFactory implementation has no innate knowledge of column types. All it knows
+        // is that TIME_COLUMN_NAME is a long.
+
+        if (Column.TIME_COLUMN_NAME.equals(columnName)) {
+          return ValueType.LONG;
+        } else {
+          // Return null, caller will assume default types in this case.
+          return null;
+        }
       }
 
       @Override
@@ -293,45 +303,16 @@ public int lookupId(String name)
           }
         };
       }
-
-      @Override
-      public NumericColumnSelector makeMathExpressionSelector(String expression)
-      {
-        final Expr parsed = Parser.parse(expression);
-
-        final List required = Parser.findRequiredBindings(parsed);
-        final Map> values = Maps.newHashMapWithExpectedSize(required.size());
-
-        for (final String columnName : required) {
-          values.put(
-              columnName, new Supplier()
-              {
-                @Override
-                public Number get()
-                {
-                  return Evals.toNumber(in.get().getRaw(columnName));
-                }
-              }
-          );
-        }
-        final Expr.ObjectBinding binding = Parser.withSuppliers(values);
-
-        return new NumericColumnSelector()
-        {
-          @Override
-          public Number get()
-          {
-            return parsed.eval(binding).numericValue();
-          }
-        };
-      }
     };
+
+    return virtualColumns.wrap(baseFactory);
   }
 
   private final long minTimestamp;
   private final QueryGranularity gran;
   private final boolean rollup;
   private final List> rowTransformers;
+  private final VirtualColumns virtualColumns;
   private final AggregatorFactory[] metrics;
   private final AggregatorType[] aggs;
   private final boolean deserializeComplexMetrics;
@@ -375,6 +356,7 @@ public IncrementalIndex(
     this.minTimestamp = incrementalIndexSchema.getMinTimestamp();
     this.gran = incrementalIndexSchema.getGran();
     this.rollup = incrementalIndexSchema.isRollup();
+    this.virtualColumns = incrementalIndexSchema.getVirtualColumns();
     this.metrics = incrementalIndexSchema.getMetrics();
     this.rowTransformers = new CopyOnWriteArrayList<>();
     this.deserializeComplexMetrics = deserializeComplexMetrics;
@@ -1052,6 +1034,15 @@ public int hashCode()
     }
   }
 
+  protected ColumnSelectorFactory makeColumnSelectorFactory(
+      final AggregatorFactory agg,
+      final Supplier in,
+      final boolean deserializeComplexMetrics
+  )
+  {
+    return makeColumnSelectorFactory(virtualColumns, agg, in, deserializeComplexMetrics);
+  }
+
   protected final Comparator dimsComparator()
   {
     return new TimeAndDimsComp(dimensionDescsList);
diff --git a/processing/src/main/java/io/druid/segment/incremental/IncrementalIndexSchema.java b/processing/src/main/java/io/druid/segment/incremental/IncrementalIndexSchema.java
index b3bbfb187896..ca26a95b9d2b 100644
--- a/processing/src/main/java/io/druid/segment/incremental/IncrementalIndexSchema.java
+++ b/processing/src/main/java/io/druid/segment/incremental/IncrementalIndexSchema.java
@@ -25,6 +25,7 @@
 import io.druid.granularity.QueryGranularities;
 import io.druid.granularity.QueryGranularity;
 import io.druid.query.aggregation.AggregatorFactory;
+import io.druid.segment.VirtualColumns;
 
 /**
  */
@@ -34,6 +35,7 @@ public class IncrementalIndexSchema
   private final long minTimestamp;
   private final TimestampSpec timestampSpec;
   private final QueryGranularity gran;
+  private final VirtualColumns virtualColumns;
   private final DimensionsSpec dimensionsSpec;
   private final AggregatorFactory[] metrics;
   private final boolean rollup;
@@ -42,6 +44,7 @@ public IncrementalIndexSchema(
       long minTimestamp,
       TimestampSpec timestampSpec,
       QueryGranularity gran,
+      VirtualColumns virtualColumns,
       DimensionsSpec dimensionsSpec,
       AggregatorFactory[] metrics,
       boolean rollup
@@ -50,6 +53,7 @@ public IncrementalIndexSchema(
     this.minTimestamp = minTimestamp;
     this.timestampSpec = timestampSpec;
     this.gran = gran;
+    this.virtualColumns = virtualColumns == null ? VirtualColumns.EMPTY : virtualColumns;
     this.dimensionsSpec = dimensionsSpec;
     this.metrics = metrics;
     this.rollup = rollup;
@@ -70,6 +74,11 @@ public QueryGranularity getGran()
     return gran;
   }
 
+  public VirtualColumns getVirtualColumns()
+  {
+    return virtualColumns;
+  }
+
   public DimensionsSpec getDimensionsSpec()
   {
     return dimensionsSpec;
@@ -90,6 +99,7 @@ public static class Builder
     private long minTimestamp;
     private TimestampSpec timestampSpec;
     private QueryGranularity gran;
+    private VirtualColumns virtualColumns;
     private DimensionsSpec dimensionsSpec;
     private AggregatorFactory[] metrics;
     private boolean rollup;
@@ -98,6 +108,7 @@ public Builder()
     {
       this.minTimestamp = 0L;
       this.gran = QueryGranularities.NONE;
+      this.virtualColumns = VirtualColumns.EMPTY;
       this.dimensionsSpec = new DimensionsSpec(null, null, null);
       this.metrics = new AggregatorFactory[]{};
       this.rollup = true;
@@ -133,6 +144,12 @@ public Builder withQueryGranularity(QueryGranularity gran)
       return this;
     }
 
+    public Builder withVirtualColumns(VirtualColumns virtualColumns)
+    {
+      this.virtualColumns = virtualColumns;
+      return this;
+    }
+
     public Builder withDimensionsSpec(DimensionsSpec dimensionsSpec)
     {
       this.dimensionsSpec = dimensionsSpec == null ? DimensionsSpec.ofEmpty() : dimensionsSpec;
@@ -167,7 +184,7 @@ public Builder withRollup(boolean rollup)
     public IncrementalIndexSchema build()
     {
       return new IncrementalIndexSchema(
-          minTimestamp, timestampSpec, gran, dimensionsSpec, metrics, rollup
+          minTimestamp, timestampSpec, gran, virtualColumns, dimensionsSpec, metrics, rollup
       );
     }
   }
diff --git a/processing/src/main/java/io/druid/segment/incremental/IncrementalIndexStorageAdapter.java b/processing/src/main/java/io/druid/segment/incremental/IncrementalIndexStorageAdapter.java
index 443abed638ae..bc984f5b4ebe 100644
--- a/processing/src/main/java/io/druid/segment/incremental/IncrementalIndexStorageAdapter.java
+++ b/processing/src/main/java/io/druid/segment/incremental/IncrementalIndexStorageAdapter.java
@@ -21,15 +21,10 @@
 
 import com.google.common.base.Function;
 import com.google.common.base.Strings;
-import com.google.common.base.Supplier;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterators;
 import com.google.common.collect.Lists;
-import com.google.common.collect.Maps;
-
 import io.druid.granularity.QueryGranularity;
-import io.druid.math.expr.Expr;
-import io.druid.math.expr.Parser;
 import io.druid.java.util.common.guava.Sequence;
 import io.druid.java.util.common.guava.Sequences;
 import io.druid.query.QueryInterruptedException;
@@ -50,34 +45,30 @@
 import io.druid.segment.LongColumnSelector;
 import io.druid.segment.Metadata;
 import io.druid.segment.NullDimensionSelector;
-import io.druid.segment.NumericColumnSelector;
 import io.druid.segment.ObjectColumnSelector;
 import io.druid.segment.SingleScanTimeDimSelector;
 import io.druid.segment.StorageAdapter;
-import io.druid.segment.VirtualColumn;
-import io.druid.segment.VirtualColumns;
+import io.druid.segment.ZeroFloatColumnSelector;
+import io.druid.segment.ZeroLongColumnSelector;
 import io.druid.segment.column.Column;
 import io.druid.segment.column.ColumnCapabilities;
-import io.druid.segment.column.ColumnCapabilitiesImpl;
 import io.druid.segment.column.ValueType;
 import io.druid.segment.data.Indexed;
 import io.druid.segment.data.ListIndexed;
 import io.druid.segment.filter.BooleanValueMatcher;
 import io.druid.segment.filter.Filters;
+import io.druid.segment.VirtualColumns;
 import org.joda.time.DateTime;
 import org.joda.time.Interval;
 
 import javax.annotation.Nullable;
 import java.util.Iterator;
-import java.util.List;
 import java.util.Map;
 
 /**
  */
 public class IncrementalIndexStorageAdapter implements StorageAdapter
 {
-  private static final NullDimensionSelector NULL_DIMENSION_SELECTOR = new NullDimensionSelector();
-
   private final IncrementalIndex index;
 
   public IncrementalIndexStorageAdapter(
@@ -352,6 +343,10 @@ public DimensionSelector makeDimensionSelector(
                   DimensionSpec dimensionSpec
               )
               {
+                if (virtualColumns.exists(dimensionSpec.getDimension())) {
+                  return virtualColumns.makeDimensionSelector(dimensionSpec, this);
+                }
+
                 final String dimension = dimensionSpec.getDimension();
                 final ExtractionFn extractionFn = dimensionSpec.getExtractionFn();
 
@@ -366,7 +361,7 @@ public DimensionSelector makeDimensionSelector(
 
                 final IncrementalIndex.DimensionDesc dimensionDesc = index.getDimension(dimensionSpec.getDimension());
                 if (dimensionDesc == null) {
-                  return dimensionSpec.decorate(NULL_DIMENSION_SELECTOR);
+                  return dimensionSpec.decorate(NullDimensionSelector.instance());
                 }
 
                 final DimensionIndexer indexer = dimensionDesc.getIndexer();
@@ -376,6 +371,10 @@ public DimensionSelector makeDimensionSelector(
               @Override
               public FloatColumnSelector makeFloatColumnSelector(String columnName)
               {
+                if (virtualColumns.exists(columnName)) {
+                  return virtualColumns.makeFloatColumnSelector(columnName, this);
+                }
+
                 final Integer dimIndex = index.getDimensionIndex(columnName);
                 if (dimIndex != null) {
                   final IncrementalIndex.DimensionDesc dimensionDesc = index.getDimension(columnName);
@@ -389,14 +388,7 @@ public FloatColumnSelector makeFloatColumnSelector(String columnName)
 
                 final Integer metricIndexInt = index.getMetricIndex(columnName);
                 if (metricIndexInt == null) {
-                  return new FloatColumnSelector()
-                  {
-                    @Override
-                    public float get()
-                    {
-                      return 0.0f;
-                    }
-                  };
+                  return ZeroFloatColumnSelector.instance();
                 }
 
                 final int metricIndex = metricIndexInt;
@@ -413,6 +405,10 @@ public float get()
               @Override
               public LongColumnSelector makeLongColumnSelector(String columnName)
               {
+                if (virtualColumns.exists(columnName)) {
+                  return virtualColumns.makeLongColumnSelector(columnName, this);
+                }
+
                 if (columnName.equals(Column.TIME_COLUMN_NAME)) {
                   return new LongColumnSelector()
                   {
@@ -437,14 +433,7 @@ public long get()
 
                 final Integer metricIndexInt = index.getMetricIndex(columnName);
                 if (metricIndexInt == null) {
-                  return new LongColumnSelector()
-                  {
-                    @Override
-                    public long get()
-                    {
-                      return 0L;
-                    }
-                  };
+                  return ZeroLongColumnSelector.instance();
                 }
 
                 final int metricIndex = metricIndexInt;
@@ -465,6 +454,10 @@ public long get()
               @Override
               public ObjectColumnSelector makeObjectColumnSelector(String column)
               {
+                if (virtualColumns.exists(column)) {
+                  return virtualColumns.makeObjectColumnSelector(column, this);
+                }
+
                 if (column.equals(Column.TIME_COLUMN_NAME)) {
                   return new ObjectColumnSelector()
                   {
@@ -508,10 +501,6 @@ public Object get()
                 IncrementalIndex.DimensionDesc dimensionDesc = index.getDimension(column);
 
                 if (dimensionDesc == null) {
-                  VirtualColumn virtualColumn = virtualColumns.getVirtualColumn(column);
-                  if (virtualColumn != null) {
-                    return virtualColumn.init(column, this);
-                  }
                   return null;
                 } else {
 
@@ -548,66 +537,10 @@ public Object get()
               }
 
               @Override
-              public ColumnCapabilities getColumnCapabilities(String columnName)
+              public ValueType getNativeType(String columnName)
               {
-                ColumnCapabilities capabilities = index.getCapabilities(columnName);
-                if (capabilities == null && !virtualColumns.isEmpty()) {
-                  VirtualColumn virtualColumn = virtualColumns.getVirtualColumn(columnName);
-                  if (virtualColumn != null) {
-                    Class clazz = virtualColumn.init(columnName, this).classOfObject();
-                    capabilities = new ColumnCapabilitiesImpl().setType(ValueType.typeFor(clazz));
-                  }
-                }
-                return capabilities;
-              }
-
-              @Override
-              public NumericColumnSelector makeMathExpressionSelector(String expression)
-              {
-                final Expr parsed = Parser.parse(expression);
-
-                final List required = Parser.findRequiredBindings(parsed);
-                final Map> values = Maps.newHashMapWithExpectedSize(required.size());
-
-                for (String columnName : index.getMetricNames()) {
-                  if (!required.contains(columnName)) {
-                    continue;
-                  }
-                  ValueType type = index.getCapabilities(columnName).getType();
-                  if (type == ValueType.FLOAT) {
-                    final int metricIndex = index.getMetricIndex(columnName);
-                    values.put(
-                        columnName, new Supplier()
-                        {
-                          @Override
-                          public Number get()
-                          {
-                            return index.getMetricFloatValue(currEntry.getValue(), metricIndex);
-                          }
-                        }
-                    );
-                  } else if (type == ValueType.LONG) {
-                    final int metricIndex = index.getMetricIndex(columnName);
-                    values.put(
-                        columnName, new Supplier()
-                        {
-                          @Override
-                          public Number get()
-                          {
-                            return index.getMetricLongValue(currEntry.getValue(), metricIndex);
-                          }
-                        }
-                    );
-                  }
-                }
-                final Expr.ObjectBinding binding = Parser.withSuppliers(values);
-                return new NumericColumnSelector() {
-                  @Override
-                  public Number get()
-                  {
-                    return parsed.eval(binding).numericValue();
-                  }
-                };
+                final ColumnCapabilities capabilities = index.getCapabilities(columnName);
+                return capabilities != null ? capabilities.getType() : virtualColumns.getNativeType(columnName);
               }
             };
           }
diff --git a/processing/src/main/java/io/druid/segment/incremental/OffheapIncrementalIndex.java b/processing/src/main/java/io/druid/segment/incremental/OffheapIncrementalIndex.java
index a0f654b40519..4655d7c27623 100644
--- a/processing/src/main/java/io/druid/segment/incremental/OffheapIncrementalIndex.java
+++ b/processing/src/main/java/io/druid/segment/incremental/OffheapIncrementalIndex.java
@@ -91,31 +91,6 @@ public OffheapIncrementalIndex(
     aggBuffers.add(bb);
   }
 
-  public OffheapIncrementalIndex(
-      long minTimestamp,
-      QueryGranularity gran,
-      final AggregatorFactory[] metrics,
-      boolean deserializeComplexMetrics,
-      boolean reportParseExceptions,
-      boolean sortFacts,
-      int maxRowCount,
-      StupidPool bufferPool
-  )
-  {
-    this(
-        new IncrementalIndexSchema.Builder().withMinTimestamp(minTimestamp)
-                                            .withQueryGranularity(gran)
-                                            .withMetrics(metrics)
-                                            .withRollup(IncrementalIndexSchema.DEFAULT_ROLLUP)
-                                            .build(),
-        deserializeComplexMetrics,
-        reportParseExceptions,
-        sortFacts,
-        maxRowCount,
-        bufferPool
-    );
-  }
-
   public OffheapIncrementalIndex(
       long minTimestamp,
       QueryGranularity gran,
@@ -177,8 +152,7 @@ protected BufferAggregator[] initAggs(
       ColumnSelectorFactory columnSelectorFactory = makeColumnSelectorFactory(
           agg,
           rowSupplier,
-          deserializeComplexMetrics,
-          getColumnCapabilities()
+          deserializeComplexMetrics
       );
 
       selectors.put(
@@ -229,7 +203,7 @@ protected Integer addToFacts(
           for (int i = 0; i < metrics.length; i++) {
             final AggregatorFactory agg = metrics[i];
             getAggs()[i] = agg.factorizeBuffered(
-                makeColumnSelectorFactory(agg, rowSupplier, deserializeComplexMetrics, getColumnCapabilities())
+                makeColumnSelectorFactory(agg, rowSupplier, deserializeComplexMetrics)
             );
           }
           rowContainer.set(null);
diff --git a/processing/src/main/java/io/druid/segment/incremental/OnheapIncrementalIndex.java b/processing/src/main/java/io/druid/segment/incremental/OnheapIncrementalIndex.java
index 4604b9ce8e04..f7c29a80b1ad 100644
--- a/processing/src/main/java/io/druid/segment/incremental/OnheapIncrementalIndex.java
+++ b/processing/src/main/java/io/druid/segment/incremental/OnheapIncrementalIndex.java
@@ -33,9 +33,8 @@
 import io.druid.segment.DimensionSelector;
 import io.druid.segment.FloatColumnSelector;
 import io.druid.segment.LongColumnSelector;
-import io.druid.segment.NumericColumnSelector;
 import io.druid.segment.ObjectColumnSelector;
-import io.druid.segment.column.ColumnCapabilities;
+import io.druid.segment.column.ValueType;
 
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
@@ -158,7 +157,7 @@ protected Aggregator[] initAggs(
     for (AggregatorFactory agg : metrics) {
       selectors.put(
           agg.getName(),
-          new ObjectCachingColumnSelectorFactory(makeColumnSelectorFactory(agg, rowSupplier, deserializeComplexMetrics, getColumnCapabilities()))
+          new ObjectCachingColumnSelectorFactory(makeColumnSelectorFactory(agg, rowSupplier, deserializeComplexMetrics))
       );
     }
 
@@ -404,16 +403,9 @@ public ObjectColumnSelector makeObjectColumnSelector(String columnName)
     }
 
     @Override
-    public ColumnCapabilities getColumnCapabilities(String columnName)
+    public ValueType getNativeType(String columnName)
     {
-      return delegate.getColumnCapabilities(columnName);
-    }
-
-    @Override
-    public NumericColumnSelector makeMathExpressionSelector(String expression)
-    {
-      return delegate.makeMathExpressionSelector(expression);
+      return delegate.getNativeType(columnName);
     }
   }
-
 }
diff --git a/processing/src/main/java/io/druid/segment/virtual/AbstractSingleValueVirtualDimensionSelector.java b/processing/src/main/java/io/druid/segment/virtual/AbstractSingleValueVirtualDimensionSelector.java
new file mode 100644
index 000000000000..2671c5fa152c
--- /dev/null
+++ b/processing/src/main/java/io/druid/segment/virtual/AbstractSingleValueVirtualDimensionSelector.java
@@ -0,0 +1,89 @@
+/*
+ * Licensed to Metamarkets Group Inc. (Metamarkets) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. Metamarkets licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package io.druid.segment.virtual;
+
+import io.druid.segment.DimensionSelector;
+import io.druid.segment.data.IndexedInts;
+import it.unimi.dsi.fastutil.ints.IntIterator;
+import it.unimi.dsi.fastutil.ints.IntIterators;
+
+import java.io.IOException;
+
+public abstract class AbstractSingleValueVirtualDimensionSelector implements DimensionSelector
+{
+  private static final IndexedInts ALWAYS_ZERO = new IndexedInts()
+  {
+    @Override
+    public int size()
+    {
+      return 1;
+    }
+
+    @Override
+    public int get(int index)
+    {
+      return 0;
+    }
+
+    @Override
+    public IntIterator iterator()
+    {
+      return IntIterators.singleton(0);
+    }
+
+    @Override
+    public void fill(int index, int[] toFill)
+    {
+      throw new UnsupportedOperationException("Cannot fill");
+    }
+
+    @Override
+    public void close() throws IOException
+    {
+
+    }
+  };
+
+  protected abstract String getValue();
+
+  @Override
+  public IndexedInts getRow()
+  {
+    return ALWAYS_ZERO;
+  }
+
+  @Override
+  public int getValueCardinality()
+  {
+    return DimensionSelector.CARDINALITY_UNKNOWN;
+  }
+
+  @Override
+  public String lookupName(int id)
+  {
+    return getValue();
+  }
+
+  @Override
+  public int lookupId(String name)
+  {
+    throw new UnsupportedOperationException("Cannot lookupId on virtual dimensions");
+  }
+}
diff --git a/processing/src/main/java/io/druid/segment/virtual/ExpressionObjectColumnSelector.java b/processing/src/main/java/io/druid/segment/virtual/ExpressionObjectColumnSelector.java
new file mode 100644
index 000000000000..1c4f2d7d288b
--- /dev/null
+++ b/processing/src/main/java/io/druid/segment/virtual/ExpressionObjectColumnSelector.java
@@ -0,0 +1,141 @@
+/*
+ * Licensed to Metamarkets Group Inc. (Metamarkets) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. Metamarkets licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package io.druid.segment.virtual;
+
+import com.google.common.base.Preconditions;
+import com.google.common.base.Supplier;
+import com.google.common.collect.Maps;
+import com.google.common.primitives.Doubles;
+import io.druid.common.guava.GuavaUtils;
+import io.druid.math.expr.Expr;
+import io.druid.math.expr.Parser;
+import io.druid.segment.ColumnSelectorFactory;
+import io.druid.segment.FloatColumnSelector;
+import io.druid.segment.LongColumnSelector;
+import io.druid.segment.ObjectColumnSelector;
+import io.druid.segment.column.ValueType;
+
+import java.util.Map;
+
+class ExpressionObjectColumnSelector implements ObjectColumnSelector
+{
+  private final Expr expression;
+  private final Expr.ObjectBinding bindings;
+
+  ExpressionObjectColumnSelector(Expr expression, ColumnSelectorFactory columnSelectorFactory)
+  {
+    this.expression = Preconditions.checkNotNull(expression, "expression");
+    this.bindings = createBindings(expression, columnSelectorFactory);
+  }
+
+  private static Expr.ObjectBinding createBindings(Expr expression, ColumnSelectorFactory columnSelectorFactory)
+  {
+    final Map> suppliers = Maps.newHashMap();
+    for (String columnName : Parser.findRequiredBindings(expression)) {
+      final ValueType nativeType = columnSelectorFactory.getNativeType(columnName);
+      final Supplier supplier;
+
+      if (nativeType == ValueType.FLOAT) {
+        final FloatColumnSelector selector = columnSelectorFactory.makeFloatColumnSelector(columnName);
+        supplier = new Supplier()
+        {
+          @Override
+          public Number get()
+          {
+            return selector.get();
+          }
+        };
+      } else if (nativeType == ValueType.LONG) {
+        final LongColumnSelector selector = columnSelectorFactory.makeLongColumnSelector(columnName);
+        supplier = new Supplier()
+        {
+          @Override
+          public Number get()
+          {
+            return selector.get();
+          }
+        };
+      } else if (nativeType == null) {
+        // Unknown ValueType. Try making an Object selector and see if that gives us anything useful.
+        final ObjectColumnSelector selector = columnSelectorFactory.makeObjectColumnSelector(columnName);
+        final Class clazz = selector == null ? null : selector.classOfObject();
+        if (selector == null || (clazz != Object.class && Number.class.isAssignableFrom(clazz))) {
+          // We know there are no numbers here. Use a null supplier.
+          supplier = null;
+        } else {
+          // There may be numbers here.
+          supplier = new Supplier()
+          {
+            @Override
+            public Number get()
+            {
+              return tryParse(selector.get());
+            }
+          };
+        }
+      } else {
+        // Unhandleable ValueType (possibly STRING or COMPLEX).
+        supplier = null;
+      }
+
+      if (supplier != null) {
+        suppliers.put(columnName, supplier);
+      }
+    }
+
+    return Parser.withSuppliers(suppliers);
+  }
+
+  private static Number tryParse(final Object value)
+  {
+    if (value == null) {
+      return 0L;
+    }
+
+    if (value instanceof Number) {
+      return (Number) value;
+    }
+
+    final String stringValue = String.valueOf(value);
+    final Long longValue = GuavaUtils.tryParseLong(stringValue);
+    if (longValue != null) {
+      return longValue;
+    }
+
+    final Double doubleValue = Doubles.tryParse(stringValue);
+    if (doubleValue != null) {
+      return doubleValue;
+    }
+
+    return 0L;
+  }
+
+  @Override
+  public Class classOfObject()
+  {
+    return Number.class;
+  }
+
+  @Override
+  public Number get()
+  {
+    return expression.eval(bindings).numericValue();
+  }
+}
diff --git a/processing/src/main/java/io/druid/segment/virtual/ExpressionVirtualColumn.java b/processing/src/main/java/io/druid/segment/virtual/ExpressionVirtualColumn.java
new file mode 100644
index 000000000000..5ae7a8014511
--- /dev/null
+++ b/processing/src/main/java/io/druid/segment/virtual/ExpressionVirtualColumn.java
@@ -0,0 +1,212 @@
+/*
+ * Licensed to Metamarkets Group Inc. (Metamarkets) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. Metamarkets licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package io.druid.segment.virtual;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.google.common.base.Preconditions;
+import com.google.common.primitives.Ints;
+import io.druid.math.expr.Expr;
+import io.druid.math.expr.Parser;
+import io.druid.query.dimension.DimensionSpec;
+import io.druid.segment.ColumnSelectorFactory;
+import io.druid.segment.DimensionSelector;
+import io.druid.segment.FloatColumnSelector;
+import io.druid.segment.LongColumnSelector;
+import io.druid.segment.ObjectColumnSelector;
+import io.druid.segment.VirtualColumn;
+import io.druid.segment.column.ValueType;
+import org.apache.commons.codec.Charsets;
+
+import java.nio.ByteBuffer;
+import java.util.List;
+
+public class ExpressionVirtualColumn implements VirtualColumn
+{
+  private final String name;
+  private final String expression;
+  private final Expr parsedExpression;
+
+  @JsonCreator
+  public ExpressionVirtualColumn(
+      @JsonProperty("name") String name,
+      @JsonProperty("expression") String expression
+  )
+  {
+    this.name = Preconditions.checkNotNull(name, "name");
+    this.expression = Preconditions.checkNotNull(expression, "expression");
+    this.parsedExpression = Parser.parse(expression);
+  }
+
+  @JsonProperty("name")
+  @Override
+  public String getOutputName()
+  {
+    return name;
+  }
+
+  @JsonProperty
+  public String getExpression()
+  {
+    return expression;
+  }
+
+  @Override
+  public ObjectColumnSelector makeObjectColumnSelector(
+      final String columnName,
+      final ColumnSelectorFactory columnSelectorFactory
+  )
+  {
+    return new ExpressionObjectColumnSelector(parsedExpression, columnSelectorFactory);
+  }
+
+  @Override
+  public DimensionSelector makeDimensionSelector(
+      final DimensionSpec dimensionSpec,
+      final ColumnSelectorFactory columnSelectorFactory
+  )
+  {
+    final ExpressionObjectColumnSelector numericSelector = new ExpressionObjectColumnSelector(
+        parsedExpression,
+        columnSelectorFactory
+    );
+    class ExpressionDimensionSelector extends AbstractSingleValueVirtualDimensionSelector
+    {
+      @Override
+      protected String getValue()
+      {
+        final Number number = numericSelector.get();
+        return number == null ? null : String.valueOf(number);
+      }
+    }
+    return new ExpressionDimensionSelector();
+  }
+
+  @Override
+  public FloatColumnSelector makeFloatColumnSelector(
+      final String columnName,
+      final ColumnSelectorFactory columnSelectorFactory
+  )
+  {
+    final ExpressionObjectColumnSelector numericSelector = new ExpressionObjectColumnSelector(
+        parsedExpression,
+        columnSelectorFactory
+    );
+    return new FloatColumnSelector()
+    {
+      @Override
+      public float get()
+      {
+        final Number number = numericSelector.get();
+        return number == null ? 0.0f : number.floatValue();
+      }
+    };
+  }
+
+  @Override
+  public LongColumnSelector makeLongColumnSelector(
+      final String columnName,
+      final ColumnSelectorFactory columnSelectorFactory
+  )
+  {
+    final ExpressionObjectColumnSelector numericSelector = new ExpressionObjectColumnSelector(
+        parsedExpression,
+        columnSelectorFactory
+    );
+    return new LongColumnSelector()
+    {
+      @Override
+      public long get()
+      {
+        final Number number = numericSelector.get();
+        return number == null ? 0L : number.longValue();
+      }
+    };
+  }
+
+  @Override
+  public ValueType nativeType(String columnName)
+  {
+    return ValueType.FLOAT;
+  }
+
+  @Override
+  public List requiredColumns()
+  {
+    return Parser.findRequiredBindings(expression);
+  }
+
+  @Override
+  public boolean usesDotNotation()
+  {
+    return false;
+  }
+
+  @Override
+  public byte[] getCacheKey()
+  {
+    final byte[] nameBytes = name.getBytes(Charsets.UTF_8);
+    final byte[] expressionBytes = expression.getBytes(Charsets.UTF_8);
+
+    return ByteBuffer
+        .allocate(1 + Ints.BYTES * 2 + nameBytes.length + expressionBytes.length)
+        .put(VirtualColumnCacheHelper.CACHE_TYPE_ID_EXPRESSION)
+        .putInt(nameBytes.length)
+        .put(nameBytes)
+        .putInt(expressionBytes.length)
+        .put(expressionBytes)
+        .array();
+  }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+
+    ExpressionVirtualColumn that = (ExpressionVirtualColumn) o;
+
+    if (!name.equals(that.name)) {
+      return false;
+    }
+    return expression.equals(that.expression);
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = name.hashCode();
+    result = 31 * result + expression.hashCode();
+    return result;
+  }
+
+  @Override
+  public String toString()
+  {
+    return "ExpressionVirtualColumn{" +
+           "name='" + name + '\'' +
+           ", expression='" + expression + '\'' +
+           '}';
+  }
+}
diff --git a/processing/src/main/java/io/druid/segment/virtual/VirtualColumnCacheHelper.java b/processing/src/main/java/io/druid/segment/virtual/VirtualColumnCacheHelper.java
new file mode 100644
index 000000000000..7c7bba2edd9d
--- /dev/null
+++ b/processing/src/main/java/io/druid/segment/virtual/VirtualColumnCacheHelper.java
@@ -0,0 +1,34 @@
+/*
+ * Licensed to Metamarkets Group Inc. (Metamarkets) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. Metamarkets licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package io.druid.segment.virtual;
+
+public class VirtualColumnCacheHelper
+{
+  public static final byte CACHE_TYPE_ID_MAP = 0x00;
+  public static final byte CACHE_TYPE_ID_EXPRESSION = 0x01;
+
+  // Starting byte 0xFF is reserved for site-specific virtual columns.
+  public static final byte CACHE_TYPE_ID_USER_DEFINED = (byte) 0xFF;
+
+  private VirtualColumnCacheHelper()
+  {
+    // No instantiation.
+  }
+}
diff --git a/processing/src/main/java/io/druid/segment/virtual/VirtualizedColumnSelectorFactory.java b/processing/src/main/java/io/druid/segment/virtual/VirtualizedColumnSelectorFactory.java
new file mode 100644
index 000000000000..967cd176cf78
--- /dev/null
+++ b/processing/src/main/java/io/druid/segment/virtual/VirtualizedColumnSelectorFactory.java
@@ -0,0 +1,92 @@
+/*
+ * Licensed to Metamarkets Group Inc. (Metamarkets) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. Metamarkets licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package io.druid.segment.virtual;
+
+import com.google.common.base.Preconditions;
+import io.druid.query.dimension.DimensionSpec;
+import io.druid.segment.ColumnSelectorFactory;
+import io.druid.segment.DimensionSelector;
+import io.druid.segment.FloatColumnSelector;
+import io.druid.segment.LongColumnSelector;
+import io.druid.segment.ObjectColumnSelector;
+import io.druid.segment.VirtualColumns;
+import io.druid.segment.column.ValueType;
+
+public class VirtualizedColumnSelectorFactory implements ColumnSelectorFactory
+{
+  private final ColumnSelectorFactory baseFactory;
+  private final VirtualColumns virtualColumns;
+
+  public VirtualizedColumnSelectorFactory(
+      ColumnSelectorFactory baseFactory,
+      VirtualColumns virtualColumns
+  )
+  {
+    this.baseFactory = Preconditions.checkNotNull(baseFactory, "baseFactory");
+    this.virtualColumns = Preconditions.checkNotNull(virtualColumns, "virtualColumns");
+  }
+
+  @Override
+  public DimensionSelector makeDimensionSelector(DimensionSpec dimensionSpec)
+  {
+    if (virtualColumns.exists(dimensionSpec.getDimension())) {
+      return virtualColumns.makeDimensionSelector(dimensionSpec, baseFactory);
+    } else {
+      return baseFactory.makeDimensionSelector(dimensionSpec);
+    }
+  }
+
+  @Override
+  public FloatColumnSelector makeFloatColumnSelector(String columnName)
+  {
+    if (virtualColumns.exists(columnName)) {
+      return virtualColumns.makeFloatColumnSelector(columnName, baseFactory);
+    } else {
+      return baseFactory.makeFloatColumnSelector(columnName);
+    }
+  }
+
+  @Override
+  public LongColumnSelector makeLongColumnSelector(String columnName)
+  {
+    if (virtualColumns.exists(columnName)) {
+      return virtualColumns.makeLongColumnSelector(columnName, baseFactory);
+    } else {
+      return baseFactory.makeLongColumnSelector(columnName);
+    }
+  }
+
+  @Override
+  public ObjectColumnSelector makeObjectColumnSelector(String columnName)
+  {
+    if (virtualColumns.exists(columnName)) {
+      return virtualColumns.makeObjectColumnSelector(columnName, baseFactory);
+    } else {
+      return baseFactory.makeObjectColumnSelector(columnName);
+    }
+  }
+
+  @Override
+  public ValueType getNativeType(String columnName)
+  {
+    final ValueType virtualType = virtualColumns.getNativeType(columnName);
+    return virtualType != null ? virtualType : baseFactory.getNativeType(columnName);
+  }
+}
diff --git a/processing/src/test/java/io/druid/query/SchemaEvolutionTest.java b/processing/src/test/java/io/druid/query/SchemaEvolutionTest.java
index 8aa5997c109a..687023840531 100644
--- a/processing/src/test/java/io/druid/query/SchemaEvolutionTest.java
+++ b/processing/src/test/java/io/druid/query/SchemaEvolutionTest.java
@@ -49,6 +49,7 @@
 import io.druid.segment.QueryableIndex;
 import io.druid.segment.QueryableIndexSegment;
 import io.druid.segment.incremental.IncrementalIndexSchema;
+import io.druid.segment.virtual.ExpressionVirtualColumn;
 import org.joda.time.DateTime;
 import org.junit.After;
 import org.junit.Assert;
@@ -257,12 +258,15 @@ public void testNumericEvolutionTimeseriesAggregation()
         .newTimeseriesQueryBuilder()
         .dataSource(DATA_SOURCE)
         .intervals("1000/3000")
+        .virtualColumns(
+            new ExpressionVirtualColumn("expr", "c1 * 1")
+        )
         .aggregators(
             ImmutableList.of(
                 new LongSumAggregatorFactory("a", "c1"),
                 new DoubleSumAggregatorFactory("b", "c1"),
-                new LongSumAggregatorFactory("c", null, "c1 * 1"),
-                new DoubleSumAggregatorFactory("d", null, "c1 * 1")
+                new LongSumAggregatorFactory("c", "expr"),
+                new DoubleSumAggregatorFactory("d", "expr")
             )
         )
         .build();
diff --git a/processing/src/test/java/io/druid/query/aggregation/FilteredAggregatorTest.java b/processing/src/test/java/io/druid/query/aggregation/FilteredAggregatorTest.java
index 042c5ed34a68..4073a0570b64 100644
--- a/processing/src/test/java/io/druid/query/aggregation/FilteredAggregatorTest.java
+++ b/processing/src/test/java/io/druid/query/aggregation/FilteredAggregatorTest.java
@@ -40,10 +40,7 @@
 import io.druid.segment.DimensionSelector;
 import io.druid.segment.FloatColumnSelector;
 import io.druid.segment.LongColumnSelector;
-import io.druid.segment.NumericColumnSelector;
 import io.druid.segment.ObjectColumnSelector;
-import io.druid.segment.column.ColumnCapabilities;
-import io.druid.segment.column.ColumnCapabilitiesImpl;
 import io.druid.segment.column.ValueType;
 import io.druid.segment.data.ArrayBasedIndexedInts;
 import io.druid.segment.data.IndexedInts;
@@ -167,27 +164,13 @@ public ObjectColumnSelector makeObjectColumnSelector(String columnName)
       }
 
       @Override
-      public ColumnCapabilities getColumnCapabilities(String columnName)
+      public ValueType getNativeType(String columnName)
       {
-        ColumnCapabilitiesImpl caps;
         if (columnName.equals("value")) {
-          caps = new ColumnCapabilitiesImpl();
-          caps.setType(ValueType.FLOAT);
-          caps.setDictionaryEncoded(false);
-          caps.setHasBitmapIndexes(false);
+          return ValueType.FLOAT;
         } else {
-          caps = new ColumnCapabilitiesImpl();
-          caps.setType(ValueType.STRING);
-          caps.setDictionaryEncoded(true);
-          caps.setHasBitmapIndexes(true);
+          return ValueType.STRING;
         }
-        return caps;
-      }
-
-      @Override
-      public NumericColumnSelector makeMathExpressionSelector(String expression)
-      {
-        throw new UnsupportedOperationException();
       }
     };
   }
diff --git a/processing/src/test/java/io/druid/query/aggregation/JavaScriptAggregatorTest.java b/processing/src/test/java/io/druid/query/aggregation/JavaScriptAggregatorTest.java
index 3bb6d26fe65a..55e8fbcae753 100644
--- a/processing/src/test/java/io/druid/query/aggregation/JavaScriptAggregatorTest.java
+++ b/processing/src/test/java/io/druid/query/aggregation/JavaScriptAggregatorTest.java
@@ -28,9 +28,8 @@
 import io.druid.segment.DimensionSelector;
 import io.druid.segment.FloatColumnSelector;
 import io.druid.segment.LongColumnSelector;
-import io.druid.segment.NumericColumnSelector;
 import io.druid.segment.ObjectColumnSelector;
-import io.druid.segment.column.ColumnCapabilities;
+import io.druid.segment.column.ValueType;
 import org.junit.Assert;
 import org.junit.Rule;
 import org.junit.Test;
@@ -73,13 +72,7 @@ public ObjectColumnSelector makeObjectColumnSelector(String columnName)
     }
 
     @Override
-    public ColumnCapabilities getColumnCapabilities(String columnName)
-    {
-      return null;
-    }
-
-    @Override
-    public NumericColumnSelector makeMathExpressionSelector(String expression)
+    public ValueType getNativeType(String columnName)
     {
       return null;
     }
diff --git a/processing/src/test/java/io/druid/query/groupby/GroupByQueryRunnerTest.java b/processing/src/test/java/io/druid/query/groupby/GroupByQueryRunnerTest.java
index 0c36dea67a3d..051d24841740 100644
--- a/processing/src/test/java/io/druid/query/groupby/GroupByQueryRunnerTest.java
+++ b/processing/src/test/java/io/druid/query/groupby/GroupByQueryRunnerTest.java
@@ -107,6 +107,7 @@
 import io.druid.query.spec.MultipleIntervalSegmentSpec;
 import io.druid.segment.TestHelper;
 import io.druid.segment.column.Column;
+import io.druid.segment.virtual.ExpressionVirtualColumn;
 import org.joda.time.DateTime;
 import org.joda.time.DateTimeZone;
 import org.joda.time.Interval;
@@ -2203,16 +2204,33 @@ public void testMergeResultsAcrossMultipleDaysWithLimitAndOrderBy()
     TestHelper.assertExpectedObjects(
         Iterables.limit(expectedResults, limit), mergeRunner.run(fullQuery, context), String.format("limit: %d", limit)
     );
+  }
 
-    builder.setAggregatorSpecs(
-        Arrays.asList(
-            QueryRunnerTestHelper.rowsCount,
-            new LongSumAggregatorFactory("idx", null, "index * 2 + indexMin / 10")
+  @Test
+  public void testMergeResultsAcrossMultipleDaysWithLimitAndOrderByUsingMathExpressions()
+  {
+    final int limit = 14;
+    GroupByQuery.Builder builder = GroupByQuery
+        .builder()
+        .setDataSource(QueryRunnerTestHelper.dataSource)
+        .setInterval(QueryRunnerTestHelper.firstToThird)
+        .setVirtualColumns(
+            new ExpressionVirtualColumn("expr", "index * 2 + indexMin / 10")
         )
-    );
-    fullQuery = builder.build();
+        .setDimensions(Lists.newArrayList(new DefaultDimensionSpec("quality", "alias")))
+        .setAggregatorSpecs(
+            Arrays.asList(
+                QueryRunnerTestHelper.rowsCount,
+                new LongSumAggregatorFactory("idx", "expr")
+            )
+        )
+        .setGranularity(QueryGranularities.DAY)
+        .setLimit(limit)
+        .addOrderByColumn("idx", OrderByColumnSpec.Direction.DESCENDING);
+
+    GroupByQuery fullQuery = builder.build();
 
-    expectedResults = Arrays.asList(
+    List expectedResults = Arrays.asList(
         GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "premium", "rows", 3L, "idx", 6090L),
         GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "mezzanine", "rows", 3L, "idx", 6030L),
         GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "entertainment", "rows", 1L, "idx", 333L),
@@ -2230,8 +2248,9 @@ public void testMergeResultsAcrossMultipleDaysWithLimitAndOrderBy()
         GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "travel", "rows", 1L, "idx", 265L)
     );
 
-    mergeRunner = factory.getToolchest().mergeResults(runner);
+    QueryRunner mergeRunner = factory.getToolchest().mergeResults(runner);
 
+    Map context = Maps.newHashMap();
     TestHelper.assertExpectedObjects(
         Iterables.limit(expectedResults, limit), mergeRunner.run(fullQuery, context), String.format("limit: %d", limit)
     );
@@ -2405,10 +2424,13 @@ public void testGroupByOrderLimit() throws Exception
     );
 
     builder.limit(Integer.MAX_VALUE)
+           .setVirtualColumns(
+               new ExpressionVirtualColumn("expr", "index / 2 + indexMin")
+           )
            .setAggregatorSpecs(
                Arrays.asList(
                    QueryRunnerTestHelper.rowsCount,
-                   new DoubleSumAggregatorFactory("idx", null, "index / 2 + indexMin")
+                   new DoubleSumAggregatorFactory("idx", "expr")
                )
            );
 
@@ -3991,13 +4013,17 @@ public void testDifferentGroupingSubquery()
         GroupByQueryRunnerTestHelper.runQuery(factory, runner, query), ""
     );
 
-    subquery = subquery.withAggregatorSpecs(
-        Arrays.asList(
-            QueryRunnerTestHelper.rowsCount,
-            new LongSumAggregatorFactory("idx", null, "-index + 100"),
-            new LongSumAggregatorFactory("indexMaxPlusTen", "indexMaxPlusTen")
+    subquery = new GroupByQuery.Builder(subquery)
+        .setVirtualColumns(
+            new ExpressionVirtualColumn("expr", "-index + 100")
         )
-    );
+        .setAggregatorSpecs(
+            Arrays.asList(
+                QueryRunnerTestHelper.rowsCount,
+                new LongSumAggregatorFactory("idx", "expr"),
+                new LongSumAggregatorFactory("indexMaxPlusTen", "indexMaxPlusTen")
+            )
+        ).build();
     query = (GroupByQuery) query.withDataSource(new QueryDataSource(subquery));
 
     expectedResults = GroupByQueryRunnerTestHelper.createExpectedRows(
@@ -5106,6 +5132,34 @@ public void testSubqueryWithContextTimeout()
     TestHelper.assertExpectedObjects(expectedResults, results, "");
   }
 
+  @Test
+  public void testSubqueryWithOuterVirtualColumns()
+  {
+    final GroupByQuery subquery = GroupByQuery
+        .builder()
+        .setDataSource(QueryRunnerTestHelper.dataSource)
+        .setQuerySegmentSpec(QueryRunnerTestHelper.fullOnInterval)
+        .setDimensions(Lists.newArrayList(new DefaultDimensionSpec("quality", "alias")))
+        .setGranularity(QueryRunnerTestHelper.dayGran)
+        .build();
+
+    final GroupByQuery query = GroupByQuery
+        .builder()
+        .setDataSource(subquery)
+        .setQuerySegmentSpec(QueryRunnerTestHelper.firstToThird)
+        .setVirtualColumns(new ExpressionVirtualColumn("expr", "1"))
+        .setDimensions(Lists.newArrayList())
+        .setAggregatorSpecs(ImmutableList.of(new LongSumAggregatorFactory("count", "expr")))
+        .setGranularity(QueryRunnerTestHelper.allGran)
+        .build();
+
+    List expectedResults = Arrays.asList(
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "count", 18L)
+    );
+    Iterable results = GroupByQueryRunnerTestHelper.runQuery(factory, runner, query);
+    TestHelper.assertExpectedObjects(expectedResults, results, "");
+  }
+
   @Test
   public void testSubqueryWithOuterCardinalityAggregator()
   {
@@ -5113,8 +5167,10 @@ public void testSubqueryWithOuterCardinalityAggregator()
         .builder()
         .setDataSource(QueryRunnerTestHelper.dataSource)
         .setQuerySegmentSpec(QueryRunnerTestHelper.fullOnInterval)
-        .setDimensions(Lists.newArrayList(new DefaultDimensionSpec("market", "market"),
-                                                         new DefaultDimensionSpec("quality", "quality")))
+        .setDimensions(Lists.newArrayList(
+            new DefaultDimensionSpec("market", "market"),
+            new DefaultDimensionSpec("quality", "quality")
+        ))
         .setAggregatorSpecs(
             Arrays.asList(
                 QueryRunnerTestHelper.rowsCount,
diff --git a/processing/src/test/java/io/druid/query/groupby/epinephelinae/TestColumnSelectorFactory.java b/processing/src/test/java/io/druid/query/groupby/epinephelinae/TestColumnSelectorFactory.java
index 8373698976c0..7b2fa7f5626b 100644
--- a/processing/src/test/java/io/druid/query/groupby/epinephelinae/TestColumnSelectorFactory.java
+++ b/processing/src/test/java/io/druid/query/groupby/epinephelinae/TestColumnSelectorFactory.java
@@ -25,9 +25,8 @@
 import io.druid.segment.DimensionSelector;
 import io.druid.segment.FloatColumnSelector;
 import io.druid.segment.LongColumnSelector;
-import io.druid.segment.NumericColumnSelector;
 import io.druid.segment.ObjectColumnSelector;
-import io.druid.segment.column.ColumnCapabilities;
+import io.druid.segment.column.ValueType;
 
 public class TestColumnSelectorFactory implements ColumnSelectorFactory
 {
@@ -90,13 +89,7 @@ public Object get()
   }
 
   @Override
-  public NumericColumnSelector makeMathExpressionSelector(String expression)
-  {
-    throw new UnsupportedOperationException("expression is not supported in current context");
-  }
-
-  @Override
-  public ColumnCapabilities getColumnCapabilities(String columnName)
+  public ValueType getNativeType(String columnName)
   {
     return null;
   }
diff --git a/processing/src/test/java/io/druid/query/select/SelectQuerySpecTest.java b/processing/src/test/java/io/druid/query/select/SelectQuerySpecTest.java
index b6f918fa6baa..9c4ee4c58ec6 100644
--- a/processing/src/test/java/io/druid/query/select/SelectQuerySpecTest.java
+++ b/processing/src/test/java/io/druid/query/select/SelectQuerySpecTest.java
@@ -60,7 +60,7 @@ public void testSerializationLegacyString() throws Exception
         + "\"granularity\":{\"type\":\"all\"},"
         + "\"dimensions\":[{\"type\":\"default\",\"dimension\":\"market\",\"outputName\":\"market\"},{\"type\":\"default\",\"dimension\":\"quality\",\"outputName\":\"quality\"}],"
         + "\"metrics\":[\"index\"],"
-        + "\"virtualColumns\":null,"
+        + "\"virtualColumns\":[],"
         + "\"pagingSpec\":{\"pagingIdentifiers\":{},\"threshold\":3,\"fromNext\":false},"
         + "\"context\":null}";
 
diff --git a/processing/src/test/java/io/druid/query/timeseries/TimeseriesQueryQueryToolChestTest.java b/processing/src/test/java/io/druid/query/timeseries/TimeseriesQueryQueryToolChestTest.java
index c005abdf1180..724b6e7fb4a7 100644
--- a/processing/src/test/java/io/druid/query/timeseries/TimeseriesQueryQueryToolChestTest.java
+++ b/processing/src/test/java/io/druid/query/timeseries/TimeseriesQueryQueryToolChestTest.java
@@ -31,6 +31,7 @@
 import io.druid.query.aggregation.AggregatorFactory;
 import io.druid.query.aggregation.CountAggregatorFactory;
 import io.druid.query.spec.MultipleIntervalSegmentSpec;
+import io.druid.segment.VirtualColumns;
 import org.joda.time.DateTime;
 import org.joda.time.Interval;
 import org.junit.Assert;
@@ -73,6 +74,7 @@ public void testCacheStrategy() throws Exception
                     )
                 ),
                 descending,
+                VirtualColumns.EMPTY,
                 null,
                 QueryGranularities.ALL,
                 ImmutableList.of(new CountAggregatorFactory("metric1")),
diff --git a/processing/src/test/java/io/druid/query/topn/TopNQueryQueryToolChestTest.java b/processing/src/test/java/io/druid/query/topn/TopNQueryQueryToolChestTest.java
index e651bbedee64..393942767f4e 100644
--- a/processing/src/test/java/io/druid/query/topn/TopNQueryQueryToolChestTest.java
+++ b/processing/src/test/java/io/druid/query/topn/TopNQueryQueryToolChestTest.java
@@ -40,6 +40,7 @@
 import io.druid.query.spec.MultipleIntervalSegmentSpec;
 import io.druid.segment.IncrementalIndexSegment;
 import io.druid.segment.TestIndex;
+import io.druid.segment.VirtualColumns;
 import org.joda.time.DateTime;
 import org.joda.time.Interval;
 import org.junit.Assert;
@@ -60,6 +61,7 @@ public void testCacheStrategy() throws Exception
         new TopNQueryQueryToolChest(null, null).getCacheStrategy(
             new TopNQuery(
                 new TableDataSource("dummy"),
+                VirtualColumns.EMPTY,
                 new DefaultDimensionSpec("test", "test"),
                 new NumericTopNMetricSpec("metric1"),
                 3,
diff --git a/processing/src/test/java/io/druid/query/topn/TopNQueryRunnerTest.java b/processing/src/test/java/io/druid/query/topn/TopNQueryRunnerTest.java
index cd12aff33f5d..2cab5e85d5ff 100644
--- a/processing/src/test/java/io/druid/query/topn/TopNQueryRunnerTest.java
+++ b/processing/src/test/java/io/druid/query/topn/TopNQueryRunnerTest.java
@@ -70,6 +70,7 @@
 import io.druid.query.timeseries.TimeseriesQuery;
 import io.druid.segment.TestHelper;
 import io.druid.segment.column.Column;
+import io.druid.segment.virtual.ExpressionVirtualColumn;
 import org.joda.time.DateTime;
 import org.joda.time.Interval;
 import org.junit.Assert;
@@ -1645,12 +1646,17 @@ public void testTopNCollapsingDimExtraction()
 
     assertExpectedResults(expectedResults, query);
 
-    query = query.withAggregatorSpecs(
-        Arrays.asList(
-            QueryRunnerTestHelper.rowsCount,
-            new DoubleSumAggregatorFactory("index", null, "-index + 100")
+    query = new TopNQueryBuilder(query)
+        .virtualColumns(
+            new ExpressionVirtualColumn("expr", "-index + 100")
         )
-    );
+        .aggregators(
+            Arrays.asList(
+                QueryRunnerTestHelper.rowsCount,
+                new DoubleSumAggregatorFactory("index", "expr")
+            )
+        )
+        .build();
 
     expectedResults = Arrays.asList(
         TopNQueryRunnerTestHelper.createExpectedRows(
diff --git a/processing/src/test/java/io/druid/segment/NullDimensionSelectorTest.java b/processing/src/test/java/io/druid/segment/NullDimensionSelectorTest.java
index aab2dff99c64..ac26061786c4 100644
--- a/processing/src/test/java/io/druid/segment/NullDimensionSelectorTest.java
+++ b/processing/src/test/java/io/druid/segment/NullDimensionSelectorTest.java
@@ -27,7 +27,7 @@
 
 public class NullDimensionSelectorTest {
 
-  private final NullDimensionSelector selector = new NullDimensionSelector();
+  private final NullDimensionSelector selector = NullDimensionSelector.instance();
 
   @Test
   public void testGetRow() throws Exception {
diff --git a/processing/src/test/java/io/druid/segment/TestIndex.java b/processing/src/test/java/io/druid/segment/TestIndex.java
index 084785933807..efc7a6405aeb 100644
--- a/processing/src/test/java/io/druid/segment/TestIndex.java
+++ b/processing/src/test/java/io/druid/segment/TestIndex.java
@@ -41,6 +41,7 @@
 import io.druid.segment.incremental.IncrementalIndexSchema;
 import io.druid.segment.incremental.OnheapIncrementalIndex;
 import io.druid.segment.serde.ComplexMetrics;
+import io.druid.segment.virtual.ExpressionVirtualColumn;
 import org.joda.time.DateTime;
 import org.joda.time.Interval;
 
@@ -78,10 +79,15 @@ public class TestIndex
   public static final String[] METRICS = new String[]{"index", "indexMin", "indexMaxPlusTen"};
   private static final Logger log = new Logger(TestIndex.class);
   private static final Interval DATA_INTERVAL = new Interval("2011-01-12T00:00:00.000Z/2011-05-01T00:00:00.000Z");
+  private static final VirtualColumns VIRTUAL_COLUMNS = VirtualColumns.create(
+      Arrays.asList(
+          new ExpressionVirtualColumn("expr", "index + 10")
+      )
+  );
   public static final AggregatorFactory[] METRIC_AGGS = new AggregatorFactory[]{
       new DoubleSumAggregatorFactory(METRICS[0], METRICS[0]),
       new DoubleMinAggregatorFactory(METRICS[1], METRICS[0]),
-      new DoubleMaxAggregatorFactory(METRICS[2], null, "index + 10"),
+      new DoubleMaxAggregatorFactory(METRICS[2], VIRTUAL_COLUMNS.getVirtualColumns()[0].getOutputName()),
       new HyperUniquesAggregatorFactory("quality_uniques", "quality")
   };
   private static final IndexSpec indexSpec = new IndexSpec();
@@ -224,6 +230,7 @@ public static IncrementalIndex makeRealtimeIndex(final CharSource source, boolea
         .withMinTimestamp(new DateTime("2011-01-12T00:00:00.000Z").getMillis())
         .withTimestampSpec(new TimestampSpec("ds", "auto", null))
         .withQueryGranularity(QueryGranularities.NONE)
+        .withVirtualColumns(VIRTUAL_COLUMNS)
         .withMetrics(METRIC_AGGS)
         .withRollup(rollup)
         .build();
diff --git a/processing/src/test/java/io/druid/segment/filter/BaseFilterTest.java b/processing/src/test/java/io/druid/segment/filter/BaseFilterTest.java
index 76e192848dd2..0223b97b261e 100644
--- a/processing/src/test/java/io/druid/segment/filter/BaseFilterTest.java
+++ b/processing/src/test/java/io/druid/segment/filter/BaseFilterTest.java
@@ -50,13 +50,13 @@
 import io.druid.segment.QueryableIndexStorageAdapter;
 import io.druid.segment.StorageAdapter;
 import io.druid.segment.TestHelper;
-import io.druid.segment.VirtualColumns;
 import io.druid.segment.data.BitmapSerdeFactory;
 import io.druid.segment.data.ConciseBitmapSerdeFactory;
 import io.druid.segment.data.IndexedInts;
 import io.druid.segment.data.RoaringBitmapSerdeFactory;
 import io.druid.segment.incremental.IncrementalIndex;
 import io.druid.segment.incremental.IncrementalIndexStorageAdapter;
+import io.druid.segment.VirtualColumns;
 import org.joda.time.Interval;
 import org.junit.Assert;
 import org.junit.Before;
diff --git a/processing/src/test/java/io/druid/segment/incremental/IncrementalIndexMultiValueSpecTest.java b/processing/src/test/java/io/druid/segment/incremental/IncrementalIndexMultiValueSpecTest.java
index 48c98f2ce892..00d0e66a0995 100644
--- a/processing/src/test/java/io/druid/segment/incremental/IncrementalIndexMultiValueSpecTest.java
+++ b/processing/src/test/java/io/druid/segment/incremental/IncrementalIndexMultiValueSpecTest.java
@@ -28,6 +28,7 @@
 import io.druid.data.input.impl.TimestampSpec;
 import io.druid.granularity.QueryGranularities;
 import io.druid.query.aggregation.AggregatorFactory;
+import io.druid.segment.VirtualColumns;
 import org.junit.Assert;
 import org.junit.Test;
 
@@ -54,6 +55,7 @@ public void test() throws IndexSizeExceededException
         0,
         new TimestampSpec("ds", "auto", null),
         QueryGranularities.ALL,
+        VirtualColumns.EMPTY,
         dimensionsSpec,
         new AggregatorFactory[0],
         false
diff --git a/processing/src/test/java/io/druid/segment/incremental/IncrementalIndexStorageAdapterTest.java b/processing/src/test/java/io/druid/segment/incremental/IncrementalIndexStorageAdapterTest.java
index 34b79506d49d..de26954395de 100644
--- a/processing/src/test/java/io/druid/segment/incremental/IncrementalIndexStorageAdapterTest.java
+++ b/processing/src/test/java/io/druid/segment/incremental/IncrementalIndexStorageAdapterTest.java
@@ -49,9 +49,9 @@
 import io.druid.segment.Cursor;
 import io.druid.segment.DimensionSelector;
 import io.druid.segment.StorageAdapter;
-import io.druid.segment.VirtualColumns;
 import io.druid.segment.data.IndexedInts;
 import io.druid.segment.filter.SelectorFilter;
+import io.druid.segment.VirtualColumns;
 import org.joda.time.DateTime;
 import org.joda.time.Interval;
 import org.junit.Assert;
@@ -264,7 +264,7 @@ public void testResetSanity() throws IOException
       Sequence cursorSequence = adapter.makeCursors(
           new SelectorFilter("sally", "bo"),
           interval,
-          null,
+          VirtualColumns.EMPTY,
           QueryGranularities.NONE,
           descending
       );
diff --git a/processing/src/test/java/io/druid/segment/incremental/OnheapIncrementalIndexBenchmark.java b/processing/src/test/java/io/druid/segment/incremental/OnheapIncrementalIndexBenchmark.java
index d7e89b337260..0bb927662cfc 100644
--- a/processing/src/test/java/io/druid/segment/incremental/OnheapIncrementalIndexBenchmark.java
+++ b/processing/src/test/java/io/druid/segment/incremental/OnheapIncrementalIndexBenchmark.java
@@ -157,9 +157,7 @@ protected Integer addToFacts(
 
         for (int i = 0; i < metrics.length; i++) {
           final AggregatorFactory agg = metrics[i];
-          aggs[i] = agg.factorize(
-              makeColumnSelectorFactory(agg, rowSupplier, deserializeComplexMetrics, null)
-          );
+          aggs[i] = agg.factorize(makeColumnSelectorFactory(agg, rowSupplier, deserializeComplexMetrics));
         }
         Integer rowIndex;
 
diff --git a/processing/src/test/java/io/druid/segment/virtual/ExpressionVirtualColumnTest.java b/processing/src/test/java/io/druid/segment/virtual/ExpressionVirtualColumnTest.java
new file mode 100644
index 000000000000..b7a227f33308
--- /dev/null
+++ b/processing/src/test/java/io/druid/segment/virtual/ExpressionVirtualColumnTest.java
@@ -0,0 +1,96 @@
+/*
+ * Licensed to Metamarkets Group Inc. (Metamarkets) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. Metamarkets licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package io.druid.segment.virtual;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import io.druid.data.input.MapBasedInputRow;
+import io.druid.query.dimension.DefaultDimensionSpec;
+import io.druid.query.groupby.epinephelinae.TestColumnSelectorFactory;
+import io.druid.segment.DimensionSelector;
+import io.druid.segment.FloatColumnSelector;
+import io.druid.segment.LongColumnSelector;
+import io.druid.segment.ObjectColumnSelector;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class ExpressionVirtualColumnTest
+{
+  @Test
+  public void testMakeSelectors()
+  {
+    final TestColumnSelectorFactory columnSelectorFactory = new TestColumnSelectorFactory();
+    final ExpressionVirtualColumn virtualColumn = new ExpressionVirtualColumn("expr", "x + y");
+
+    final ObjectColumnSelector objectSelector = virtualColumn.makeObjectColumnSelector("expr", columnSelectorFactory);
+    final DimensionSelector dimensionSelector = virtualColumn.makeDimensionSelector(
+        new DefaultDimensionSpec("expr", "x"),
+        columnSelectorFactory
+    );
+    final FloatColumnSelector floatSelector = virtualColumn.makeFloatColumnSelector("expr", columnSelectorFactory);
+    final LongColumnSelector longSelector = virtualColumn.makeLongColumnSelector("expr", columnSelectorFactory);
+
+    columnSelectorFactory.setRow(
+        new MapBasedInputRow(
+            0,
+            ImmutableList.of(),
+            ImmutableMap.of()
+        )
+    );
+
+    Assert.assertEquals(0L, objectSelector.get());
+    Assert.assertEquals("0", dimensionSelector.lookupName(dimensionSelector.getRow().get(0)));
+    Assert.assertEquals(0.0f, floatSelector.get(), 0.0f);
+    Assert.assertEquals(0L, longSelector.get());
+
+    columnSelectorFactory.setRow(
+        new MapBasedInputRow(
+            0,
+            ImmutableList.of(),
+            ImmutableMap.of("x", 4)
+        )
+    );
+
+    Assert.assertEquals(4L, objectSelector.get());
+    Assert.assertEquals("4", dimensionSelector.lookupName(dimensionSelector.getRow().get(0)));
+    Assert.assertEquals(4f, floatSelector.get(), 0.0f);
+    Assert.assertEquals(4L, longSelector.get());
+
+    columnSelectorFactory.setRow(
+        new MapBasedInputRow(
+            0,
+            ImmutableList.of(),
+            ImmutableMap.of("x", 2.1, "y", 3L)
+        )
+    );
+
+    Assert.assertEquals(5.1d, objectSelector.get());
+    Assert.assertEquals("5.1", dimensionSelector.lookupName(dimensionSelector.getRow().get(0)));
+    Assert.assertEquals(5.1f, floatSelector.get(), 0.0f);
+    Assert.assertEquals(5L, longSelector.get());
+  }
+
+  @Test
+  public void testRequiredColumns()
+  {
+    final ExpressionVirtualColumn virtualColumn = new ExpressionVirtualColumn("expr", "x + y");
+    Assert.assertEquals(ImmutableList.of("x", "y"), virtualColumn.requiredColumns());
+  }
+}
diff --git a/processing/src/test/java/io/druid/segment/virtual/VirtualColumnsTest.java b/processing/src/test/java/io/druid/segment/virtual/VirtualColumnsTest.java
new file mode 100644
index 000000000000..70a8d54620af
--- /dev/null
+++ b/processing/src/test/java/io/druid/segment/virtual/VirtualColumnsTest.java
@@ -0,0 +1,377 @@
+/*
+ * Licensed to Metamarkets Group Inc. (Metamarkets) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. Metamarkets licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package io.druid.segment.virtual;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.google.common.collect.ImmutableList;
+import com.google.common.primitives.Longs;
+import io.druid.jackson.DefaultObjectMapper;
+import io.druid.query.dimension.DefaultDimensionSpec;
+import io.druid.query.dimension.DimensionSpec;
+import io.druid.query.extraction.ExtractionFn;
+import io.druid.segment.ColumnSelectorFactory;
+import io.druid.segment.DimensionSelector;
+import io.druid.segment.FloatColumnSelector;
+import io.druid.segment.LongColumnSelector;
+import io.druid.segment.ObjectColumnSelector;
+import io.druid.segment.VirtualColumn;
+import io.druid.segment.VirtualColumns;
+import io.druid.segment.column.ValueType;
+import io.druid.segment.data.IndexedInts;
+import it.unimi.dsi.fastutil.ints.IntIterator;
+import it.unimi.dsi.fastutil.ints.IntIterators;
+import org.junit.Assert;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.List;
+
+public class VirtualColumnsTest
+{
+  @Rule
+  public ExpectedException expectedException = ExpectedException.none();
+
+  @Test
+  public void testMakeSelectors()
+  {
+    final VirtualColumns virtualColumns = makeVirtualColumns();
+    final ObjectColumnSelector objectSelector = virtualColumns.makeObjectColumnSelector("expr", null);
+    final DimensionSelector dimensionSelector = virtualColumns.makeDimensionSelector(
+        new DefaultDimensionSpec("expr", "x"),
+        null
+    );
+    final FloatColumnSelector floatSelector = virtualColumns.makeFloatColumnSelector("expr", null);
+    final LongColumnSelector longSelector = virtualColumns.makeLongColumnSelector("expr", null);
+
+    Assert.assertEquals(1L, objectSelector.get());
+    Assert.assertEquals("1", dimensionSelector.lookupName(dimensionSelector.getRow().get(0)));
+    Assert.assertEquals(1.0f, floatSelector.get(), 0.0f);
+    Assert.assertEquals(1L, longSelector.get());
+  }
+
+  @Test
+  public void testMakeSelectorsWithDotSupport()
+  {
+    final VirtualColumns virtualColumns = makeVirtualColumns();
+    final ObjectColumnSelector objectSelector = virtualColumns.makeObjectColumnSelector("foo.5", null);
+    final DimensionSelector dimensionSelector = virtualColumns.makeDimensionSelector(
+        new DefaultDimensionSpec("foo.5", "x"),
+        null
+    );
+    final FloatColumnSelector floatSelector = virtualColumns.makeFloatColumnSelector("foo.5", null);
+    final LongColumnSelector longSelector = virtualColumns.makeLongColumnSelector("foo.5", null);
+
+    Assert.assertEquals(5L, objectSelector.get());
+    Assert.assertEquals("5", dimensionSelector.lookupName(dimensionSelector.getRow().get(0)));
+    Assert.assertEquals(5.0f, floatSelector.get(), 0.0f);
+    Assert.assertEquals(5L, longSelector.get());
+  }
+
+  @Test
+  public void testMakeSelectorsWithDotSupportBaseNameOnly()
+  {
+    final VirtualColumns virtualColumns = makeVirtualColumns();
+    final ObjectColumnSelector objectSelector = virtualColumns.makeObjectColumnSelector("foo", null);
+    final DimensionSelector dimensionSelector = virtualColumns.makeDimensionSelector(
+        new DefaultDimensionSpec("foo", "x"),
+        null
+    );
+    final FloatColumnSelector floatSelector = virtualColumns.makeFloatColumnSelector("foo", null);
+    final LongColumnSelector longSelector = virtualColumns.makeLongColumnSelector("foo", null);
+
+    Assert.assertEquals(-1L, objectSelector.get());
+    Assert.assertEquals("-1", dimensionSelector.lookupName(dimensionSelector.getRow().get(0)));
+    Assert.assertEquals(-1.0f, floatSelector.get(), 0.0f);
+    Assert.assertEquals(-1L, longSelector.get());
+  }
+
+  @Test
+  public void testTimeNotAllowed()
+  {
+    final ExpressionVirtualColumn expr = new ExpressionVirtualColumn("__time", "x + y");
+
+    expectedException.expect(IllegalArgumentException.class);
+    expectedException.expectMessage("virtualColumn name[__time] not allowed");
+
+    VirtualColumns.create(ImmutableList.of(expr));
+  }
+
+  @Test
+  public void testDuplicateNameDetection()
+  {
+    final ExpressionVirtualColumn expr = new ExpressionVirtualColumn("expr", "x + y");
+    final ExpressionVirtualColumn expr2 = new ExpressionVirtualColumn("expr", "x * 2");
+
+    expectedException.expect(IllegalArgumentException.class);
+    expectedException.expectMessage("Duplicate virtualColumn name[expr]");
+
+    VirtualColumns.create(ImmutableList.of(expr, expr2));
+  }
+
+  @Test
+  public void testCycleDetection()
+  {
+    final ExpressionVirtualColumn expr = new ExpressionVirtualColumn("expr", "x + expr2");
+    final ExpressionVirtualColumn expr2 = new ExpressionVirtualColumn("expr2", "expr * 2");
+
+    expectedException.expect(IllegalArgumentException.class);
+    expectedException.expectMessage("Self-referential column[expr]");
+
+    VirtualColumns.create(ImmutableList.of(expr, expr2));
+  }
+
+  @Test
+  public void testGetCacheKey() throws Exception
+  {
+    final VirtualColumns virtualColumns = VirtualColumns.create(
+        ImmutableList.of(
+            new ExpressionVirtualColumn("expr", "x + y")
+        )
+    );
+
+    final VirtualColumns virtualColumns2 = VirtualColumns.create(
+        ImmutableList.of(
+            new ExpressionVirtualColumn("expr", "x + y")
+        )
+    );
+
+    Assert.assertArrayEquals(virtualColumns.getCacheKey(), virtualColumns2.getCacheKey());
+    Assert.assertFalse(Arrays.equals(virtualColumns.getCacheKey(), VirtualColumns.EMPTY.getCacheKey()));
+  }
+
+  @Test
+  public void testEqualsAndHashCode() throws Exception
+  {
+    final VirtualColumns virtualColumns = VirtualColumns.create(
+        ImmutableList.of(
+            new ExpressionVirtualColumn("expr", "x + y")
+        )
+    );
+
+    final VirtualColumns virtualColumns2 = VirtualColumns.create(
+        ImmutableList.of(
+            new ExpressionVirtualColumn("expr", "x + y")
+        )
+    );
+
+    Assert.assertEquals(virtualColumns, virtualColumns);
+    Assert.assertEquals(virtualColumns, virtualColumns2);
+    Assert.assertNotEquals(VirtualColumns.EMPTY, virtualColumns);
+    Assert.assertNotEquals(VirtualColumns.EMPTY, null);
+
+    Assert.assertEquals(virtualColumns.hashCode(), virtualColumns.hashCode());
+    Assert.assertEquals(virtualColumns.hashCode(), virtualColumns2.hashCode());
+    Assert.assertNotEquals(VirtualColumns.EMPTY.hashCode(), virtualColumns.hashCode());
+  }
+
+  @Test
+  public void testSerde() throws Exception
+  {
+    final ObjectMapper mapper = new DefaultObjectMapper();
+    final ImmutableList theColumns = ImmutableList.of(
+        new ExpressionVirtualColumn("expr", "x + y"),
+        new ExpressionVirtualColumn("expr2", "x + z")
+    );
+    final VirtualColumns virtualColumns = VirtualColumns.create(theColumns);
+
+    Assert.assertEquals(
+        virtualColumns,
+        mapper.readValue(
+            mapper.writeValueAsString(virtualColumns),
+            VirtualColumns.class
+        )
+    );
+
+    Assert.assertEquals(
+        theColumns,
+        mapper.readValue(
+            mapper.writeValueAsString(virtualColumns),
+            mapper.getTypeFactory().constructParametricType(List.class, VirtualColumn.class)
+        )
+    );
+  }
+
+  private VirtualColumns makeVirtualColumns()
+  {
+    final ExpressionVirtualColumn expr = new ExpressionVirtualColumn("expr", "1");
+    final DottyVirtualColumn dotty = new DottyVirtualColumn("foo");
+    return VirtualColumns.create(ImmutableList.of(expr, dotty));
+  }
+
+  static class DottyVirtualColumn implements VirtualColumn
+  {
+    private final String name;
+
+    public DottyVirtualColumn(String name)
+    {
+      this.name = name;
+    }
+
+    @Override
+    public String getOutputName()
+    {
+      return name;
+    }
+
+    @Override
+    public ObjectColumnSelector makeObjectColumnSelector(String columnName, ColumnSelectorFactory factory)
+    {
+      final LongColumnSelector selector = makeLongColumnSelector(columnName, factory);
+      return new ObjectColumnSelector()
+      {
+        @Override
+        public Class classOfObject()
+        {
+          return Long.class;
+        }
+
+        @Override
+        public Object get()
+        {
+          return selector.get();
+        }
+      };
+    }
+
+    @Override
+    public DimensionSelector makeDimensionSelector(DimensionSpec dimensionSpec, ColumnSelectorFactory factory)
+    {
+      final LongColumnSelector selector = makeLongColumnSelector(dimensionSpec.getDimension(), factory);
+      final ExtractionFn extractionFn = dimensionSpec.getExtractionFn();
+      final DimensionSelector dimensionSelector = new DimensionSelector()
+      {
+        @Override
+        public IndexedInts getRow()
+        {
+          return new IndexedInts()
+          {
+            @Override
+            public int size()
+            {
+              return 1;
+            }
+
+            @Override
+            public int get(int index)
+            {
+              return 0;
+            }
+
+            @Override
+            public IntIterator iterator()
+            {
+              return IntIterators.singleton(0);
+            }
+
+            @Override
+            public void fill(int index, int[] toFill)
+            {
+              throw new UnsupportedOperationException("fill not supported");
+            }
+
+            @Override
+            public void close() throws IOException
+            {
+
+            }
+          };
+        }
+
+        @Override
+        public int getValueCardinality()
+        {
+          return DimensionSelector.CARDINALITY_UNKNOWN;
+        }
+
+        @Override
+        public String lookupName(int id)
+        {
+          final String stringValue = String.valueOf(selector.get());
+          return extractionFn == null ? stringValue : extractionFn.apply(stringValue);
+        }
+
+        @Override
+        public int lookupId(String name)
+        {
+          return 0;
+        }
+      };
+
+      return dimensionSpec.decorate(dimensionSelector);
+    }
+
+    @Override
+    public FloatColumnSelector makeFloatColumnSelector(String columnName, ColumnSelectorFactory factory)
+    {
+      final LongColumnSelector selector = makeLongColumnSelector(columnName, factory);
+      return new FloatColumnSelector()
+      {
+        @Override
+        public float get()
+        {
+          return selector.get();
+        }
+      };
+    }
+
+    @Override
+    public LongColumnSelector makeLongColumnSelector(String columnName, ColumnSelectorFactory factory)
+    {
+      final String subColumn = VirtualColumns.splitColumnName(columnName).rhs;
+      final Long boxed = subColumn == null ? null : Longs.tryParse(subColumn);
+      final long theLong = boxed == null ? -1 : boxed;
+      return new LongColumnSelector()
+      {
+        @Override
+        public long get()
+        {
+          return theLong;
+        }
+      };
+    }
+
+    @Override
+    public ValueType nativeType(String columnName)
+    {
+      return ValueType.LONG;
+    }
+
+    @Override
+    public List requiredColumns()
+    {
+      return ImmutableList.of();
+    }
+
+    @Override
+    public boolean usesDotNotation()
+    {
+      return true;
+    }
+
+    @Override
+    public byte[] getCacheKey()
+    {
+      throw new UnsupportedOperationException();
+    }
+  }
+}