Clone Calcite planner to access validator

core/src/main/java/org/apache/druid/common/guava/GuavaUtils.java

@@ -70,9 +70,9 @@ public static <T extends Enum<T>> T getEnumIfPresent(final Class<T> enumClass, f
   }
 
   /**
-   * If first argument is not null, return it, else return the other argument. Sort of like
-   * {@link com.google.common.base.Objects#firstNonNull(T, T)} except will not explode if both arguments are
-   * null.
+   * If first argument is not null, return it, else return the other argument.
+   * Sort of like {@link <T> com.google.common.base.Objects#firstNonNull(T, T)}
+   * except will not explode if both arguments are null.
    */
   @Nullable
   public static <T> T firstNonNull(@Nullable T arg1, @Nullable T arg2)
@@ -84,10 +84,11 @@ public static <T> T firstNonNull(@Nullable T arg1, @Nullable T arg2)
   }
 
   /**
-   * Cancel futures manually, because sometime we can't cancel all futures in {@link com.google.common.util.concurrent.Futures.CombinedFuture}
+   * Cancel futures manually, because sometime we can't cancel all futures in
+   * {code com.google.common.util.concurrent.Futures.CombinedFuture}
    * automatically. Especially when we call
-   * {@link  static <V> ListenableFuture<List<V>> com.google.common.util.concurrent.Futures#allAsList(Iterable<? extends ListenableFuture <? extends V>> futures)} to create a batch of
-   * future.
+   * {@link  static <V> ListenableFuture<List<V>> com.google.common.util.concurrent.Futures#allAsList(Iterable<? extends ListenableFuture <? extends V>> futures)}
+   * to create a batch of future.
    * @param mayInterruptIfRunning {@code true} if the thread executing this
    * task should be interrupted; otherwise, in-progress tasks are allowed
    * to complete

pom.xml

@@ -82,7 +82,9 @@
         <avatica.version>1.17.0</avatica.version>
         <avro.version>1.9.2</avro.version>
         <!-- sql/src/main/codegen/config.fmpp is based on a file from calcite-core, and needs to be
-          updated when upgrading Calcite. Refer to the top-level comments in that file for details. -->
+          updated when upgrading Calcite. Refer to the top-level comments in that file for details.
+          Also, CalcitePlanner is a clone of Calcite's PlannerImpl and may require updates when
+          Calcite is upgrade. -->
         <calcite.version>1.21.0</calcite.version>
         <datasketches.version>3.2.0</datasketches.version>
         <datasketches.memory.version>2.0.0</datasketches.memory.version>

sql/src/main/java/org/apache/calcite/prepare/DruidSqlValidator.java

@@ -0,0 +1,44 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF 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.
+ */
+
+//CHECKSTYLE.OFF: PackageName - Must be in Calcite
+
+package org.apache.calcite.prepare;
+
+import org.apache.calcite.adapter.java.JavaTypeFactory;
+import org.apache.calcite.sql.SqlOperatorTable;
+import org.apache.calcite.sql.validate.SqlConformance;
+
+/**
+ * Extend {@link CalciteSqlValidator} to make it visible to Druid.
+ * {code CalciteSqlValidator} itself is protected which is why
+ * this class is in a Calcite name space.
+ */
+public class DruidSqlValidator extends CalciteSqlValidator
+{
+  public DruidSqlValidator(
+      SqlOperatorTable opTab,
+      CalciteCatalogReader catalogReader,
+      JavaTypeFactory typeFactory,
+      SqlConformance conformance)
+  {
+    super(opTab, catalogReader, typeFactory, conformance);
+  }
+
+}