diff --git a/processing/src/main/java/io/druid/query/extraction/CascadeExtractionFn.java b/processing/src/main/java/io/druid/query/extraction/CascadeExtractionFn.java
index b3d09805ca11..fad8e529d994 100644
--- a/processing/src/main/java/io/druid/query/extraction/CascadeExtractionFn.java
+++ b/processing/src/main/java/io/druid/query/extraction/CascadeExtractionFn.java
@@ -29,9 +29,7 @@
 
 public class CascadeExtractionFn implements ExtractionFn
 {
-  private final ExtractionFn extractionFns[];
-  private final ChainedExtractionFn chainedExtractionFn;
-  private final ChainedExtractionFn DEFAULT_CHAINED_EXTRACTION_FN = new ChainedExtractionFn(
+  private static final ExtractionFn DEFAULT_CHAINED_EXTRACTION_FN = new ChainedExtractionFn(
       new ExtractionFn()
       {
         public byte[] getCacheKey()
@@ -39,11 +37,6 @@ public byte[] getCacheKey()
           return new byte[0];
         }
 
-        public String apply(Object value)
-        {
-          return null;
-        }
-
         public String apply(String value)
         {
           return null;
@@ -73,6 +66,9 @@ public String toString()
       null
   );
 
+  private final ExtractionFn extractionFns[];
+  private final ExtractionFn chainedExtractionFn;
+
   @JsonCreator
   public CascadeExtractionFn(
       @JsonProperty("extractionFns") ExtractionFn[] extractionFn
@@ -106,12 +102,6 @@ public byte[] getCacheKey()
     return Bytes.concat(cacheKey, chainedExtractionFn.getCacheKey());
   }
 
-  @Override
-  public String apply(Object value)
-  {
-    return chainedExtractionFn.apply(value);
-  }
-
   @Override
   public String apply(String value)
   {
@@ -171,7 +161,7 @@ public String toString()
            "extractionFns=[" + chainedExtractionFn.toString() + "]}";
   }
 
-  private class ChainedExtractionFn
+  private static class ChainedExtractionFn implements ExtractionFn
   {
     private final ExtractionFn fn;
     private final ChainedExtractionFn child;
@@ -189,11 +179,6 @@ public byte[] getCacheKey()
       return (child != null) ? Bytes.concat(fnCacheKey, child.getCacheKey()) : fnCacheKey;
     }
 
-    public String apply(Object value)
-    {
-      return fn.apply((child != null) ? child.apply(value) : value);
-    }
-
     public String apply(String value)
     {
       return fn.apply((child != null) ? child.apply(value) : value);
@@ -201,7 +186,7 @@ public String apply(String value)
 
     public String apply(long value)
     {
-      return fn.apply((child != null) ? child.apply(value) : value);
+      return child != null ? fn.apply(child.apply(value)) : fn.apply(value);
     }
 
     public boolean preservesOrdering()
@@ -219,6 +204,7 @@ public ExtractionType getExtractionType()
       }
     }
 
+    @Override
     public boolean equals(Object o)
     {
       if (this == o) {
@@ -240,6 +226,7 @@ public boolean equals(Object o)
       return true;
     }
 
+    @Override
     public int hashCode()
     {
       int result = fn.hashCode();
@@ -249,6 +236,7 @@ public int hashCode()
       return result;
     }
 
+    @Override
     public String toString()
     {
       return (child != null)
diff --git a/processing/src/main/java/io/druid/query/extraction/DimExtractionFn.java b/processing/src/main/java/io/druid/query/extraction/DimExtractionFn.java
index afb22cd567b7..140fdb8eb2f3 100644
--- a/processing/src/main/java/io/druid/query/extraction/DimExtractionFn.java
+++ b/processing/src/main/java/io/druid/query/extraction/DimExtractionFn.java
@@ -21,12 +21,6 @@
 
 public abstract class DimExtractionFn implements ExtractionFn
 {
-  @Override
-  public String apply(Object value)
-  {
-    return apply(value == null ? null : value.toString());
-  }
-
   @Override
   public String apply(long value)
   {
diff --git a/processing/src/main/java/io/druid/query/extraction/ExtractionFn.java b/processing/src/main/java/io/druid/query/extraction/ExtractionFn.java
index f62adf78ebd5..ef0899d4699e 100644
--- a/processing/src/main/java/io/druid/query/extraction/ExtractionFn.java
+++ b/processing/src/main/java/io/druid/query/extraction/ExtractionFn.java
@@ -69,8 +69,6 @@ public interface ExtractionFn
    *
    * @return a value that should be used instead of the original
    */
-  public String apply(Object value);
-
   public String apply(String value);
 
   public String apply(long value);
diff --git a/processing/src/main/java/io/druid/query/extraction/IdentityExtractionFn.java b/processing/src/main/java/io/druid/query/extraction/IdentityExtractionFn.java
index 9d9153efabd1..86f335da7d66 100644
--- a/processing/src/main/java/io/druid/query/extraction/IdentityExtractionFn.java
+++ b/processing/src/main/java/io/druid/query/extraction/IdentityExtractionFn.java
@@ -36,12 +36,6 @@ public byte[] getCacheKey()
     return new byte[]{ExtractionCacheHelper.CACHE_TYPE_ID_IDENTITY};
   }
 
-  @Override
-  public String apply(Object value)
-  {
-    return value == null ? null : Strings.emptyToNull(value.toString());
-  }
-
   @Override
   public String apply(String value)
   {
diff --git a/processing/src/main/java/io/druid/query/extraction/JavaScriptExtractionFn.java b/processing/src/main/java/io/druid/query/extraction/JavaScriptExtractionFn.java
index 0263ddc10aa9..16252b42ece7 100644
--- a/processing/src/main/java/io/druid/query/extraction/JavaScriptExtractionFn.java
+++ b/processing/src/main/java/io/druid/query/extraction/JavaScriptExtractionFn.java
@@ -100,22 +100,16 @@ public byte[] getCacheKey()
                      .array();
   }
 
-  @Override
-  public String apply(Object value)
-  {
-    return Strings.emptyToNull(fn.apply(value));
-  }
-
   @Override
   public String apply(String value)
   {
-    return this.apply((Object) value);
+    return Strings.emptyToNull(fn.apply(value));
   }
 
   @Override
   public String apply(long value)
   {
-    return this.apply((Long) value);
+    return Strings.emptyToNull(fn.apply(value));
   }
 
   @Override
diff --git a/processing/src/main/java/io/druid/query/extraction/LowerExtractionFn.java b/processing/src/main/java/io/druid/query/extraction/LowerExtractionFn.java
index 4f3b87b8dbf7..df5d6dda6b99 100644
--- a/processing/src/main/java/io/druid/query/extraction/LowerExtractionFn.java
+++ b/processing/src/main/java/io/druid/query/extraction/LowerExtractionFn.java
@@ -88,10 +88,4 @@ public byte[] getCacheKey()
                      .put(localeBytes)
                      .array();
   }
-
-  @Override
-  public String apply(Object value)
-  {
-    return apply(String.valueOf(value));
-  }
 }
diff --git a/processing/src/main/java/io/druid/query/extraction/TimeFormatExtractionFn.java b/processing/src/main/java/io/druid/query/extraction/TimeFormatExtractionFn.java
index 2ee2011e7010..d8595f21c6ad 100644
--- a/processing/src/main/java/io/druid/query/extraction/TimeFormatExtractionFn.java
+++ b/processing/src/main/java/io/druid/query/extraction/TimeFormatExtractionFn.java
@@ -91,16 +91,10 @@ public String apply(long value)
     return formatter.print(value);
   }
 
-  @Override
-  public String apply(Object value)
-  {
-    return formatter.print(new DateTime(value));
-  }
-
   @Override
   public String apply(String value)
   {
-    return apply((Object) value);
+    return formatter.print(new DateTime(value));
   }
 
   @Override
diff --git a/processing/src/main/java/io/druid/query/extraction/UpperExtractionFn.java b/processing/src/main/java/io/druid/query/extraction/UpperExtractionFn.java
index 7d6ded1e8a4a..08f9157bc10d 100644
--- a/processing/src/main/java/io/druid/query/extraction/UpperExtractionFn.java
+++ b/processing/src/main/java/io/druid/query/extraction/UpperExtractionFn.java
@@ -87,10 +87,4 @@ public byte[] getCacheKey()
                      .put(localeBytes)
                      .array();
   }
-
-  @Override
-  public String apply(Object value)
-  {
-    return apply(String.valueOf(value));
-  }
 }
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 2f0a6bf92d16..980529c42784 100644
--- a/processing/src/main/java/io/druid/query/groupby/GroupByQueryQueryToolChest.java
+++ b/processing/src/main/java/io/druid/query/groupby/GroupByQueryQueryToolChest.java
@@ -370,7 +370,7 @@ public Row apply(Row input)
           Map<String, Object> event = Maps.newHashMap(preMapRow.getEvent());
           for (String dim : optimizedDims) {
             final Object eventVal = event.get(dim);
-            event.put(dim, extractionFnMap.get(dim).apply(eventVal));
+            event.put(dim, extractionFnMap.get(dim).apply((String)eventVal));
           }
           return new MapBasedRow(preMapRow.getTimestamp(), event);
         } else {
diff --git a/processing/src/test/java/io/druid/query/extraction/JavaScriptExtractionFnTest.java b/processing/src/test/java/io/druid/query/extraction/JavaScriptExtractionFnTest.java
index f861f97ce19c..f5ce482c2f16 100644
--- a/processing/src/test/java/io/druid/query/extraction/JavaScriptExtractionFnTest.java
+++ b/processing/src/test/java/io/druid/query/extraction/JavaScriptExtractionFnTest.java
@@ -25,6 +25,7 @@
 import io.druid.jackson.DefaultObjectMapper;
 import org.joda.time.DateTime;
 import org.junit.Assert;
+import org.junit.Ignore;
 import org.junit.Test;
 
 import java.util.Iterator;
@@ -69,11 +70,12 @@ public void testLongs() throws Exception
     Assert.assertEquals("number", new JavaScriptExtractionFn(typeOf, false).apply(1234L));
   }
 
-  @Test
+  // we don't have float type dimension. no need to test what is not possible
+  @Ignore
   public void testFloats() throws Exception
   {
-    String typeOf = "function(x) {\nreturn typeof x\n}";
-    Assert.assertEquals("number", new JavaScriptExtractionFn(typeOf, false).apply(1234.0));
+//    String typeOf = "function(x) {\nreturn typeof x\n}";
+//    Assert.assertEquals("number", new JavaScriptExtractionFn(typeOf, false).apply(1234.0F));
   }
 
   @Test