diff --git a/extensions/histogram/src/test/java/io/druid/query/aggregation/histogram/ApproximateHistogramGroupByQueryTest.java b/extensions/histogram/src/test/java/io/druid/query/aggregation/histogram/ApproximateHistogramGroupByQueryTest.java
index 1ab0308ffd8..3409fa5acc2 100644
--- a/extensions/histogram/src/test/java/io/druid/query/aggregation/histogram/ApproximateHistogramGroupByQueryTest.java
+++ b/extensions/histogram/src/test/java/io/druid/query/aggregation/histogram/ApproximateHistogramGroupByQueryTest.java
@@ -214,4 +214,64 @@ public class ApproximateHistogramGroupByQueryTest
     Iterable<Row> results = GroupByQueryRunnerTestHelper.runQuery(factory, runner, query);
     TestHelper.assertExpectedObjects(expectedResults, results, "approx-histo");
   }
+
+  @Test(expected = IllegalArgumentException.class)
+  public void testGroupByWithSameNameComplexPostAgg()
+  {
+    ApproximateHistogramAggregatorFactory aggFactory = new ApproximateHistogramAggregatorFactory(
+        "quantile",
+        "index",
+        10,
+        5,
+        Float.NEGATIVE_INFINITY,
+        Float.POSITIVE_INFINITY
+    );
+
+    GroupByQuery query = new GroupByQuery.Builder()
+        .setDataSource(QueryRunnerTestHelper.dataSource)
+        .setGranularity(QueryRunnerTestHelper.allGran)
+        .setDimensions(
+            Arrays.<DimensionSpec>asList(
+                new DefaultDimensionSpec(
+                    QueryRunnerTestHelper.marketDimension,
+                    "marketalias"
+                )
+            )
+        )
+        .setInterval(QueryRunnerTestHelper.fullOnInterval)
+        .setLimitSpec(
+            new DefaultLimitSpec(
+                Lists.newArrayList(
+                    new OrderByColumnSpec(
+                        "marketalias",
+                        OrderByColumnSpec.Direction.DESCENDING
+                    )
+                ), 1
+            )
+        )
+        .setAggregatorSpecs(
+            Lists.newArrayList(
+                QueryRunnerTestHelper.rowsCount,
+                aggFactory
+            )
+        )
+        .setPostAggregatorSpecs(
+            Arrays.<PostAggregator>asList(
+                new QuantilePostAggregator("quantile", "quantile", 0.5f)
+            )
+        )
+        .build();
+
+    List<Row> expectedResults = Arrays.asList(
+        GroupByQueryRunnerTestHelper.createExpectedRow(
+            "1970-01-01T00:00:00.000Z",
+            "marketalias", "upfront",
+            "rows", 186L,
+            "quantile", 880.9881f
+        )
+    );
+
+    Iterable<Row> results = GroupByQueryRunnerTestHelper.runQuery(factory, runner, query);
+    TestHelper.assertExpectedObjects(expectedResults, results, "approx-histo");
+  }
 }
diff --git a/processing/src/main/java/io/druid/query/Queries.java b/processing/src/main/java/io/druid/query/Queries.java
index b7bddc69b4e..c248dd0aeea 100644
--- a/processing/src/main/java/io/druid/query/Queries.java
+++ b/processing/src/main/java/io/druid/query/Queries.java
@@ -17,9 +17,7 @@
 
 package io.druid.query;
 
-import com.google.common.base.Function;
 import com.google.common.base.Preconditions;
-import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
 import io.druid.query.aggregation.AggregatorFactory;
 import io.druid.query.aggregation.PostAggregator;
@@ -39,30 +37,23 @@ public class Queries
     Preconditions.checkNotNull(aggFactories, "aggregations cannot be null");
     Preconditions.checkArgument(aggFactories.size() > 0, "Must have at least one AggregatorFactory");
 
+    final Set<String> aggNames = Sets.newHashSet();
+    for (AggregatorFactory aggFactory : aggFactories) {
+      Preconditions.checkArgument(aggNames.add(aggFactory.getName()), "[%s] already defined", aggFactory.getName());
+    }
+
     if (postAggs != null && !postAggs.isEmpty()) {
-      Set<String> combinedAggNames = Sets.newHashSet(
-          Lists.transform(
-              aggFactories,
-              new Function<AggregatorFactory, String>()
-              {
-                @Override
-                public String apply(AggregatorFactory input)
-                {
-                  return input.getName();
-                }
-              }
-          )
-      );
+      final Set<String> combinedAggNames = Sets.newHashSet(aggNames);
 
       for (PostAggregator postAgg : postAggs) {
-        Set<String> dependencies = postAgg.getDependentFields();
-        Set<String> missing = Sets.difference(dependencies, combinedAggNames);
+        final Set<String> dependencies = postAgg.getDependentFields();
+        final Set<String> missing = Sets.difference(dependencies, combinedAggNames);
 
         Preconditions.checkArgument(
             missing.isEmpty(),
             "Missing fields [%s] for postAggregator [%s]", missing, postAgg.getName()
         );
-        combinedAggNames.add(postAgg.getName());
+        Preconditions.checkArgument(combinedAggNames.add(postAgg.getName()), "[%s] already defined");
       }
     }
   }
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 258abbc389a..7102bee31ac 100644
--- a/processing/src/main/java/io/druid/query/groupby/GroupByQueryQueryToolChest.java
+++ b/processing/src/main/java/io/druid/query/groupby/GroupByQueryQueryToolChest.java
@@ -21,10 +21,13 @@ import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.common.base.Function;
 import com.google.common.base.Supplier;
+import com.google.common.collect.Collections2;
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import com.google.common.collect.Ordering;
+import com.google.common.collect.Sets;
 import com.google.inject.Inject;
 import com.metamx.common.ISE;
 import com.metamx.common.Pair;
@@ -59,10 +62,12 @@ import io.druid.segment.incremental.IncrementalIndex;
 import io.druid.segment.incremental.IncrementalIndexStorageAdapter;
 import org.joda.time.DateTime;
 
+import javax.annotation.Nullable;
 import java.nio.ByteBuffer;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 /**
  */
@@ -115,15 +120,21 @@ public class GroupByQueryQueryToolChest extends QueryToolChest<Row, GroupByQuery
         }
 
         if (Boolean.valueOf(input.getContextValue(GROUP_BY_MERGE_KEY, "true"))) {
-          return mergeGroupByResults(((GroupByQuery) input), runner, responseContext
-          );
+          return mergeGroupByResults(
+              (GroupByQuery) input,
+              runner,
+              responseContext);
         }
         return runner.run(input, responseContext);
       }
     };
   }
 
-  private Sequence<Row> mergeGroupByResults(final GroupByQuery query, QueryRunner<Row> runner, Map<String, Object> context)
+  private Sequence<Row> mergeGroupByResults(
+      final GroupByQuery query,
+      QueryRunner<Row> runner,
+      Map<String, Object> context
+  )
   {
     // If there's a subquery, merge subquery results and then apply the aggregator
 
@@ -168,7 +179,28 @@ public class GroupByQueryQueryToolChest extends QueryToolChest<Row, GroupByQuery
           index
       );
     } else {
-      final IncrementalIndex index = makeIncrementalIndex(query, runner.run(query, context));
+      final IncrementalIndex index = makeIncrementalIndex(
+          query, runner.run(
+              new GroupByQuery(
+                  query.getDataSource(),
+                  query.getQuerySegmentSpec(),
+                  query.getDimFilter(),
+                  query.getGranularity(),
+                  query.getDimensions(),
+                  query.getAggregatorSpecs(),
+                  // Don't do post aggs until the end of this method.
+                  ImmutableList.<PostAggregator>of(),
+                  query.getHavingSpec(),
+                  query.getLimitSpec(),
+                  query.getContext()
+              ).withOverriddenContext(
+                  ImmutableMap.<String, Object>of(
+                      "finalize", false
+                  )
+              )
+              , context
+          )
+      );
       return new ResourceClosingSequence<>(query.applyLimit(postAggregate(query, index)), index);
     }
   }
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 10b20396cde..67a3d37fb1b 100644
--- a/processing/src/test/java/io/druid/query/groupby/GroupByQueryRunnerTest.java
+++ b/processing/src/test/java/io/druid/query/groupby/GroupByQueryRunnerTest.java
@@ -43,6 +43,7 @@ import io.druid.query.aggregation.JavaScriptAggregatorFactory;
 import io.druid.query.aggregation.LongSumAggregatorFactory;
 import io.druid.query.aggregation.MaxAggregatorFactory;
 import io.druid.query.aggregation.PostAggregator;
+import io.druid.query.aggregation.hyperloglog.HyperUniqueFinalizingPostAggregator;
 import io.druid.query.aggregation.hyperloglog.HyperUniquesAggregatorFactory;
 import io.druid.query.aggregation.post.ArithmeticPostAggregator;
 import io.druid.query.aggregation.post.ConstantPostAggregator;
@@ -250,6 +251,44 @@ public class GroupByQueryRunnerTest
     TestHelper.assertExpectedObjects(expectedResults, results, "");
   }
 
+  @Test(expected = IllegalArgumentException.class)
+  public void testGroupByWithUniquesAndPostAggWithSameName()
+  {
+    GroupByQuery query = GroupByQuery
+        .builder()
+        .setDataSource(QueryRunnerTestHelper.dataSource)
+        .setQuerySegmentSpec(QueryRunnerTestHelper.firstToThird)
+        .setAggregatorSpecs(
+            Arrays.<AggregatorFactory>asList(
+                QueryRunnerTestHelper.rowsCount,
+                new HyperUniquesAggregatorFactory(
+                    "quality_uniques",
+                    "quality_uniques"
+                )
+            )
+        )
+        .setPostAggregatorSpecs(
+            Arrays.<PostAggregator>asList(
+                new HyperUniqueFinalizingPostAggregator("quality_uniques")
+            )
+        )
+        .setGranularity(QueryRunnerTestHelper.allGran)
+        .build();
+
+    List<Row> expectedResults = Arrays.asList(
+        GroupByQueryRunnerTestHelper.createExpectedRow(
+            "2011-04-01",
+            "rows",
+            26L,
+            "quality_uniques",
+            QueryRunnerTestHelper.UNIQUES_9
+        )
+    );
+
+    Iterable<Row> results = GroupByQueryRunnerTestHelper.runQuery(factory, runner, query);
+    TestHelper.assertExpectedObjects(expectedResults, results, "");
+  }
+
   @Test
   public void testGroupByWithCardinality()
   {
@@ -1151,6 +1190,115 @@ public class GroupByQueryRunnerTest
     TestHelper.assertExpectedObjects(expectedResults, results, "order-limit");
   }
 
+  @Test
+  public void testPostAggMergedHavingSpec()
+  {
+    List<Row> expectedResults = Arrays.asList(
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "mezzanine", "rows", 6L, "index", 4420L, QueryRunnerTestHelper.addRowsIndexConstantMetric,(double) (6l+4420l+1l)),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "premium", "rows", 6L, "index", 4416L, QueryRunnerTestHelper.addRowsIndexConstantMetric, (double) (6l+4416l+1l))
+    );
+
+    GroupByQuery.Builder builder = GroupByQuery
+        .builder()
+        .setDataSource(QueryRunnerTestHelper.dataSource)
+        .setInterval("2011-04-02/2011-04-04")
+        .setDimensions(Lists.<DimensionSpec>newArrayList(new DefaultDimensionSpec("quality", "alias")))
+        .setAggregatorSpecs(
+            Arrays.asList(
+                QueryRunnerTestHelper.rowsCount,
+                new LongSumAggregatorFactory("index", "index")
+            )
+        )
+        .setPostAggregatorSpecs(ImmutableList.<PostAggregator>of(QueryRunnerTestHelper.addRowsIndexConstant))
+        .setGranularity(new PeriodGranularity(new Period("P1M"), null, null))
+        .setHavingSpec(
+            new OrHavingSpec(
+                ImmutableList.<HavingSpec>of(
+                    new GreaterThanHavingSpec(QueryRunnerTestHelper.addRowsIndexConstantMetric, 1000L)
+                )
+            )
+        );
+
+    final GroupByQuery fullQuery = builder.build();
+
+    QueryRunner mergedRunner = factory.getToolchest().mergeResults(
+        new QueryRunner<Row>()
+        {
+          @Override
+          public Sequence<Row> run(
+              Query<Row> query, Map<String, Object> responseContext
+          )
+          {
+            // simulate two daily segments
+            final Query query1 = query.withQuerySegmentSpec(
+                new MultipleIntervalSegmentSpec(Lists.newArrayList(new Interval("2011-04-02/2011-04-03")))
+            );
+            final Query query2 = query.withQuerySegmentSpec(
+                new MultipleIntervalSegmentSpec(Lists.newArrayList(new Interval("2011-04-03/2011-04-04")))
+            );
+            return Sequences.concat(runner.run(query1, responseContext), runner.run(query2, responseContext));
+          }
+        }
+    );
+
+    Map<String, Object> context = Maps.newHashMap();
+    TestHelper.assertExpectedObjects(expectedResults, mergedRunner.run(fullQuery, context), "merged");
+  }
+
+  @Test
+  public void testPostAggHavingSpec()
+  {
+    List<Row> expectedResults = Arrays.asList(
+        GroupByQueryRunnerTestHelper.createExpectedRow(
+            "2011-04-01",
+            "alias",
+            "mezzanine",
+            "rows",
+            6L,
+            "index",
+            4420L,
+            QueryRunnerTestHelper.addRowsIndexConstantMetric,
+            (double) (6l + 4420l + 1l)
+        ),
+        GroupByQueryRunnerTestHelper.createExpectedRow(
+            "2011-04-01",
+            "alias",
+            "premium",
+            "rows",
+            6L,
+            "index",
+            4416L,
+            QueryRunnerTestHelper.addRowsIndexConstantMetric,
+            (double) (6l + 4416l + 1l)
+        )
+    );
+
+    GroupByQuery.Builder builder = GroupByQuery
+        .builder()
+        .setDataSource(QueryRunnerTestHelper.dataSource)
+        .setInterval("2011-04-02/2011-04-04")
+        .setDimensions(Lists.<DimensionSpec>newArrayList(new DefaultDimensionSpec("quality", "alias")))
+        .setAggregatorSpecs(
+            Arrays.asList(
+                QueryRunnerTestHelper.rowsCount,
+                new LongSumAggregatorFactory("index", "index")
+            )
+        )
+        .setPostAggregatorSpecs(ImmutableList.<PostAggregator>of(QueryRunnerTestHelper.addRowsIndexConstant))
+        .setGranularity(new PeriodGranularity(new Period("P1M"), null, null))
+        .setHavingSpec(
+            new OrHavingSpec(
+                ImmutableList.<HavingSpec>of(
+                    new GreaterThanHavingSpec(QueryRunnerTestHelper.addRowsIndexConstantMetric, 1000L)
+                )
+            )
+        );
+
+    final GroupByQuery fullQuery = builder.build();
+    TestHelper.assertExpectedObjects(expectedResults, GroupByQueryRunnerTestHelper.runQuery(factory, runner, fullQuery), "");
+  }
+
+
   @Test
   public void testHavingSpec()
   {
@@ -1160,6 +1308,40 @@ public class GroupByQueryRunnerTest
         GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "premium", "rows", 6L, "idx", 4416L)
     );
 
+    GroupByQuery.Builder builder = GroupByQuery
+        .builder()
+        .setDataSource(QueryRunnerTestHelper.dataSource)
+        .setInterval("2011-04-02/2011-04-04")
+        .setDimensions(Lists.<DimensionSpec>newArrayList(new DefaultDimensionSpec("quality", "alias")))
+        .setAggregatorSpecs(
+            Arrays.asList(
+                QueryRunnerTestHelper.rowsCount,
+                new LongSumAggregatorFactory("idx", "index")
+            )
+        )
+        .setGranularity(new PeriodGranularity(new Period("P1M"), null, null))
+        .setHavingSpec(
+            new OrHavingSpec(
+                ImmutableList.of(
+                    new GreaterThanHavingSpec("rows", 2L),
+                    new EqualToHavingSpec("idx", 217L)
+                )
+            )
+        );
+
+    final GroupByQuery fullQuery = builder.build();
+    TestHelper.assertExpectedObjects(expectedResults, GroupByQueryRunnerTestHelper.runQuery(factory, runner, fullQuery), "");
+  }
+
+  @Test
+  public void testMergedHavingSpec()
+  {
+    List<Row> expectedResults = Arrays.asList(
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "business", "rows", 2L, "idx", 217L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "mezzanine", "rows", 6L, "idx", 4420L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "premium", "rows", 6L, "idx", 4416L)
+    );
+
     GroupByQuery.Builder builder = GroupByQuery
         .builder()
         .setDataSource(QueryRunnerTestHelper.dataSource)
@@ -1577,7 +1759,7 @@ public class GroupByQueryRunnerTest
         .setPostAggregatorSpecs(
             Arrays.<PostAggregator>asList(
                 new ArithmeticPostAggregator(
-                    "idx", "+", Arrays.asList(
+                    "idx_post", "+", Arrays.asList(
                     new FieldAccessPostAggregator("the_idx_agg", "idx"),
                     new ConstantPostAggregator("ten_thousand", 10000)
                 )
@@ -1589,41 +1771,45 @@ public class GroupByQueryRunnerTest
         .build();
 
     List<Row> expectedResults = Arrays.asList(
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "automotive", "rows", 1L, "idx", 11135.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "business", "rows", 1L, "idx", 11118.0),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "automotive", "rows", 1L, "idx_post", 11135.0, "idx", 1135L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "business", "rows", 1L, "idx_post", 11118.0, "idx", 1118L),
         GroupByQueryRunnerTestHelper.createExpectedRow(
             "2011-04-01",
             "alias",
             "entertainment",
             "rows",
             1L,
+            "idx_post",
+            11158.0,
             "idx",
-            11158.0
+            1158L
         ),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "health", "rows", 1L, "idx", 11120.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "mezzanine", "rows", 3L, "idx", 13870.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "news", "rows", 1L, "idx", 11121.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "premium", "rows", 3L, "idx", 13900.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "technology", "rows", 1L, "idx", 11078.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "travel", "rows", 1L, "idx", 11119.0),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "health", "rows", 1L, "idx_post", 11120.0, "idx", 1120L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "mezzanine", "rows", 3L, "idx_post", 13870.0, "idx", 3870L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "news", "rows", 1L, "idx_post", 11121.0, "idx", 1121L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "premium", "rows", 3L, "idx_post", 13900.0, "idx", 3900L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "technology", "rows", 1L, "idx_post", 11078.0, "idx", 1078L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "travel", "rows", 1L, "idx_post", 11119.0, "idx", 1119L),
 
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "automotive", "rows", 1L, "idx", 11147.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "business", "rows", 1L, "idx", 11112.0),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "automotive", "rows", 1L, "idx_post", 11147.0, "idx", 1147L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "business", "rows", 1L, "idx_post", 11112.0, "idx", 1112L),
         GroupByQueryRunnerTestHelper.createExpectedRow(
             "2011-04-02",
             "alias",
             "entertainment",
             "rows",
             1L,
+            "idx_post",
+            11166.0,
             "idx",
-            11166.0
+            1166L
         ),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "health", "rows", 1L, "idx", 11113.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "mezzanine", "rows", 3L, "idx", 13447.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "news", "rows", 1L, "idx", 11114.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "premium", "rows", 3L, "idx", 13505.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "technology", "rows", 1L, "idx", 11097.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "travel", "rows", 1L, "idx", 11126.0)
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "health", "rows", 1L, "idx_post", 11113.0, "idx", 1113L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "mezzanine", "rows", 3L, "idx_post", 13447.0, "idx", 3447L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "news", "rows", 1L, "idx_post", 11114.0, "idx", 1114L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "premium", "rows", 3L, "idx_post", 13505.0, "idx", 3505L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "technology", "rows", 1L, "idx_post", 11097.0, "idx", 1097L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "travel", "rows", 1L, "idx_post", 11126.0, "idx", 1126L)
     );
 
     // Subqueries are handled by the ToolChest
@@ -1693,7 +1879,7 @@ public class GroupByQueryRunnerTest
         .setPostAggregatorSpecs(
             Arrays.<PostAggregator>asList(
                 new ArithmeticPostAggregator(
-                    "idx", "+", Arrays.asList(
+                    "idx_post", "+", Arrays.asList(
                     new FieldAccessPostAggregator("the_idx_agg", "idx"),
                     new ConstantPostAggregator("ten_thousand", 10000)
                 )
@@ -1705,39 +1891,43 @@ public class GroupByQueryRunnerTest
         .build();
 
     List<Row> expectedResults = Arrays.asList(
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "automotive", "rows", 1L, "idx", 11135.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "business", "rows", 1L, "idx", 11118.0),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "automotive", "rows", 1L, "idx_post", 11135.0, "idx", 1135L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "business", "rows", 1L, "idx_post", 11118.0, "idx", 1118L),
         GroupByQueryRunnerTestHelper.createExpectedRow(
             "2011-04-01",
             "alias",
             "entertainment",
             "rows",
             1L,
+            "idx_post",
+            11158.0,
             "idx",
-            11158.0
+            1158L
         ),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "health", "rows", 1L, "idx", 11120.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "news", "rows", 1L, "idx", 11121.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "technology", "rows", 1L, "idx", 11078.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "travel", "rows", 1L, "idx", 11119.0),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "health", "rows", 1L, "idx_post", 11120.0, "idx", 1120L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "news", "rows", 1L, "idx_post", 11121.0, "idx", 1121L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "technology", "rows", 1L, "idx_post", 11078.0, "idx", 1078L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-01", "alias", "travel", "rows", 1L, "idx_post", 11119.0, "idx", 1119L),
 
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "automotive", "rows", 1L, "idx", 11147.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "business", "rows", 1L, "idx", 11112.0),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "automotive", "rows", 1L, "idx_post", 11147.0, "idx", 1147L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "business", "rows", 1L, "idx_post", 11112.0, "idx", 1112L),
         GroupByQueryRunnerTestHelper.createExpectedRow(
             "2011-04-02",
             "alias",
             "entertainment",
             "rows",
             1L,
+            "idx_post",
+            11166.0,
             "idx",
-            11166.0
+            1166L
         ),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "health", "rows", 1L, "idx", 11113.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "mezzanine", "rows", 3L, "idx", 13447.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "news", "rows", 1L, "idx", 11114.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "premium", "rows", 3L, "idx", 13505.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "technology", "rows", 1L, "idx", 11097.0),
-        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "travel", "rows", 1L, "idx", 11126.0)
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "health", "rows", 1L, "idx_post", 11113.0, "idx", 1113L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "mezzanine", "rows", 3L, "idx_post", 13447.0, "idx", 3447L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "news", "rows", 1L, "idx_post", 11114.0, "idx", 1114L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "premium", "rows", 3L, "idx_post", 13505.0, "idx", 3505L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "technology", "rows", 1L, "idx_post", 11097.0, "idx", 1097L),
+        GroupByQueryRunnerTestHelper.createExpectedRow("2011-04-02", "alias", "travel", "rows", 1L, "idx_post", 11126.0, "idx", 1126L)
     );
 
     // Subqueries are handled by the ToolChest
@@ -1815,7 +2005,7 @@ public class GroupByQueryRunnerTest
         .setPostAggregatorSpecs(
             Arrays.<PostAggregator>asList(
                 new ArithmeticPostAggregator(
-                    "idx", "+", Arrays.asList(
+                    "idx_post", "+", Arrays.asList(
                     new FieldAccessPostAggregator("the_idx_agg", "idx"),
                     new ConstantPostAggregator("ten_thousand", 10000)
                 )
@@ -1844,8 +2034,10 @@ public class GroupByQueryRunnerTest
             "travel",
             "rows",
             1L,
-            "idx",
+            "idx_post",
             11119.0,
+            "idx",
+            1119L,
             "js_outer_agg",
             123.92274475097656
         ),
@@ -1855,8 +2047,10 @@ public class GroupByQueryRunnerTest
             "technology",
             "rows",
             1L,
-            "idx",
+            "idx_post",
             11078.0,
+            "idx",
+            1078L,
             "js_outer_agg",
             82.62254333496094
         ),
@@ -1866,8 +2060,10 @@ public class GroupByQueryRunnerTest
             "news",
             "rows",
             1L,
-            "idx",
+            "idx_post",
             11121.0,
+            "idx",
+            1121L,
             "js_outer_agg",
             125.58358001708984
         ),
@@ -1877,8 +2073,10 @@ public class GroupByQueryRunnerTest
             "health",
             "rows",
             1L,
-            "idx",
+            "idx_post",
             11120.0,
+            "idx",
+            1120L,
             "js_outer_agg",
             124.13470458984375
         ),
@@ -1888,8 +2086,10 @@ public class GroupByQueryRunnerTest
             "entertainment",
             "rows",
             1L,
-            "idx",
+            "idx_post",
             11158.0,
+            "idx",
+            1158L,
             "js_outer_agg",
             162.74722290039062
         )