adding QueryGranularity to segment metadata and optionally expose same from segmentMetadata query (#2873)

docs/content/querying/segmentmetadataquery.md

@@ -49,6 +49,9 @@ The format of the result is:
   "aggregators" : {
     "metric1" : { "type" : "longSum", "name" : "metric1", "fieldName" : "metric1" }
   },
+  "queryGranularity" : {
+    "type": "none"
+  },
   "size" : 300000,
   "numRows" : 5000000
 } ]
@@ -104,7 +107,7 @@ This is a list of properties that determines the amount of information returned
 
 By default, the "cardinality", "size", "interval", and "minmax" types will be used. If a property is not needed, omitting it from this list will result in a more efficient query.
 
-There are five types of column analyses:
+Types of column analyses are described below:
 
 #### cardinality
 
@@ -123,6 +126,10 @@ dimension columns.
 
 * `intervals` in the result will contain the list of intervals associated with the queried segments.
 
+#### queryGranularity
+
+* `queryGranularity` in the result will contain query granularity of data stored in segments. this can be null if query granularity of segments was unknown or unmergeable (if merging is enabled).
+
 #### aggregators
 
 * `aggregators` in the result will contain the list of aggregators usable for querying metric columns. This may be

integration-tests/src/test/resources/hadoop/batch_hadoop_queries.json

@@ -62,7 +62,8 @@
         },
         "size": 34881,
         "numRows": 1014,
-        "aggregators": null
+        "aggregators": null,
+        "queryGranularity": null
       }
     ]
   },

integration-tests/src/test/resources/queries/twitterstream_queries.json

@@ -607,7 +607,8 @@
                 },
                 "size": 747056474,
                 "numRows": 3702583,
-                "aggregators": null
+                "aggregators": null,
+                "queryGranularity": null
             },
             {
                 "id": "twitterstream_2013-01-02T00:00:00.000Z_2013-01-03T00:00:00.000Z_2013-01-03T03:44:58.791Z_v9",
@@ -625,7 +626,8 @@
                 },
                 "size": 755796690,
                 "numRows": 3743002,
-                "aggregators": null
+                "aggregators": null,
+                "queryGranularity": null
             },
             {
                 "id": "twitterstream_2013-01-03T00:00:00.000Z_2013-01-04T00:00:00.000Z_2013-01-04T04:09:13.590Z_v9",
@@ -643,7 +645,8 @@
                 },
                 "size": 706893542,
                 "numRows":3502959,
-                "aggregators": null
+                "aggregators": null,
+                "queryGranularity": null
             }
         ]
     },

integration-tests/src/test/resources/queries/wikipedia_editstream_queries.json

@@ -1066,7 +1066,8 @@
                 },
                 "size": 902457341,
                 "numRows": 4462111,
-                "aggregators": null
+                "aggregators": null,
+                "queryGranularity": null
             }
         ]
     }

processing/src/main/java/io/druid/granularity/QueryGranularity.java

@@ -26,7 +26,9 @@ import org.joda.time.DateTime;
 import org.joda.time.Period;
 import org.joda.time.ReadableDuration;
 
+import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 
 public abstract class QueryGranularity
 {
@@ -108,4 +110,22 @@ public abstract class QueryGranularity
     }
     throw new IAE("Cannot convert [%s] to QueryGranularity", o.getClass());
   }
+
+  //simple merge strategy on query granularity that checks if all are equal or else
+  //returns null. this can be improved in future but is good enough for most use-cases.
+  public static QueryGranularity mergeQueryGranularities(List<QueryGranularity> toMerge)
+  {
+    if (toMerge == null || toMerge.size() == 0) {
+      return null;
+    }
+
+    QueryGranularity result = toMerge.get(0);
+    for (int i = 1; i < toMerge.size(); i++) {
+      if (!Objects.equals(result, toMerge.get(i))) {
+        return null;
+      }
+    }
+
+    return result;
+  }
 }

processing/src/main/java/io/druid/query/metadata/SegmentMetadataQueryQueryToolChest.java

@@ -37,6 +37,7 @@ import com.metamx.common.guava.nary.BinaryFn;
 import com.metamx.emitter.service.ServiceMetricEvent;
 import io.druid.common.guava.CombiningSequence;
 import io.druid.common.utils.JodaUtils;
+import io.druid.granularity.QueryGranularity;
 import io.druid.query.CacheStrategy;
 import io.druid.query.DruidMetrics;
 import io.druid.query.Query;
@@ -329,6 +330,13 @@ public class SegmentMetadataQueryQueryToolChest extends QueryToolChest<SegmentAn
       }
     }
 
+    final QueryGranularity queryGranularity = QueryGranularity.mergeQueryGranularities(
+        Lists.newArrayList(
+            arg1.getQueryGranularity(),
+            arg2.getQueryGranularity()
+        )
+    );
+
     final String mergedId;
 
     if (arg1.getId() != null && arg2.getId() != null && arg1.getId().equals(arg2.getId())) {
@@ -343,7 +351,8 @@ public class SegmentMetadataQueryQueryToolChest extends QueryToolChest<SegmentAn
         columns,
         arg1.getSize() + arg2.getSize(),
         arg1.getNumRows() + arg2.getNumRows(),
-        aggregators.isEmpty() ? null : aggregators
+        aggregators.isEmpty() ? null : aggregators,
+        queryGranularity
     );
   }
 
@@ -356,7 +365,8 @@ public class SegmentMetadataQueryQueryToolChest extends QueryToolChest<SegmentAn
         analysis.getColumns(),
         analysis.getSize(),
         analysis.getNumRows(),
-        analysis.getAggregators()
+        analysis.getAggregators(),
+        analysis.getQueryGranularity()
     );
   }
 }

processing/src/main/java/io/druid/query/metadata/SegmentMetadataQueryRunnerFactory.java

@@ -29,6 +29,7 @@ import com.google.inject.Inject;
 import com.metamx.common.guava.Sequence;
 import com.metamx.common.guava.Sequences;
 import com.metamx.common.logger.Logger;
+import io.druid.granularity.QueryGranularity;
 import io.druid.query.AbstractPrioritizedCallable;
 import io.druid.query.BaseQuery;
 import io.druid.query.ConcatQueryRunner;
@@ -111,8 +112,9 @@ public class SegmentMetadataQueryRunnerFactory implements QueryRunnerFactory<Seg
         List<Interval> retIntervals = query.analyzingInterval() ? Arrays.asList(segment.getDataInterval()) : null;
 
         final Map<String, AggregatorFactory> aggregators;
+        Metadata metadata = null;
         if (query.hasAggregators()) {
-          final Metadata metadata = segment.asStorageAdapter().getMetadata();
+          metadata = segment.asStorageAdapter().getMetadata();
           if (metadata != null && metadata.getAggregators() != null) {
             aggregators = Maps.newHashMap();
             for (AggregatorFactory aggregator : metadata.getAggregators()) {
@@ -125,6 +127,16 @@ public class SegmentMetadataQueryRunnerFactory implements QueryRunnerFactory<Seg
           aggregators = null;
         }
 
+        final QueryGranularity queryGranularity;
+        if (query.hasQueryGranularity()) {
+          if (metadata == null) {
+            metadata = segment.asStorageAdapter().getMetadata();
+          }
+          queryGranularity = metadata.getQueryGranularity();
+        } else {
+          queryGranularity = null;
+        }
+
         return Sequences.simple(
             Arrays.asList(
                 new SegmentAnalysis(
@@ -133,7 +145,8 @@ public class SegmentMetadataQueryRunnerFactory implements QueryRunnerFactory<Seg
                     columns,
                     totalSize,
                     numRows,
-                    aggregators
+                    aggregators,
+                    queryGranularity
                 )
             )
         );

processing/src/main/java/io/druid/query/metadata/metadata/SegmentAnalysis.java

@@ -21,6 +21,7 @@ package io.druid.query.metadata.metadata;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
+import io.druid.granularity.QueryGranularity;
 import io.druid.query.aggregation.AggregatorFactory;
 import org.joda.time.Interval;
 
@@ -36,6 +37,7 @@ public class SegmentAnalysis implements Comparable<SegmentAnalysis>
   private final long size;
   private final long numRows;
   private final Map<String, AggregatorFactory> aggregators;
+  private final QueryGranularity queryGranularity;
 
   @JsonCreator
   public SegmentAnalysis(
@@ -44,7 +46,8 @@ public class SegmentAnalysis implements Comparable<SegmentAnalysis>
       @JsonProperty("columns") Map<String, ColumnAnalysis> columns,
       @JsonProperty("size") long size,
       @JsonProperty("numRows") long numRows,
-      @JsonProperty("aggregators") Map<String, AggregatorFactory> aggregators
+      @JsonProperty("aggregators") Map<String, AggregatorFactory> aggregators,
+      @JsonProperty("queryGranularity") QueryGranularity queryGranularity
   )
   {
     this.id = id;
@@ -53,6 +56,7 @@ public class SegmentAnalysis implements Comparable<SegmentAnalysis>
     this.size = size;
     this.numRows = numRows;
     this.aggregators = aggregators;
+    this.queryGranularity = queryGranularity;
   }
 
   @JsonProperty
@@ -85,6 +89,12 @@ public class SegmentAnalysis implements Comparable<SegmentAnalysis>
     return numRows;
   }
 
+  @JsonProperty
+  public QueryGranularity getQueryGranularity()
+  {
+    return queryGranularity;
+  }
+
   @JsonProperty
   public Map<String, AggregatorFactory> getAggregators()
   {
@@ -101,6 +111,7 @@ public class SegmentAnalysis implements Comparable<SegmentAnalysis>
            ", size=" + size +
            ", numRows=" + numRows +
            ", aggregators=" + aggregators +
+           ", queryGranularity=" + queryGranularity +
            '}';
   }
 
@@ -122,7 +133,8 @@ public class SegmentAnalysis implements Comparable<SegmentAnalysis>
            Objects.equals(id, that.id) &&
            Objects.equals(interval, that.interval) &&
            Objects.equals(columns, that.columns) &&
-           Objects.equals(aggregators, that.aggregators);
+           Objects.equals(aggregators, that.aggregators) &&
+           Objects.equals(queryGranularity, that.queryGranularity);
   }
 
   /**
@@ -132,7 +144,7 @@ public class SegmentAnalysis implements Comparable<SegmentAnalysis>
   @Override
   public int hashCode()
   {
-    return Objects.hash(id, interval, columns, size, numRows, aggregators);
+    return Objects.hash(id, interval, columns, size, numRows, aggregators, queryGranularity);
   }
 
   @Override

processing/src/main/java/io/druid/query/metadata/metadata/SegmentMetadataQuery.java

@@ -54,7 +54,8 @@ public class SegmentMetadataQuery extends BaseQuery<SegmentAnalysis>
     SIZE,
     INTERVAL,
     AGGREGATORS,
-    MINMAX;
+    MINMAX,
+    QUERYGRANULARITY;
 
     @JsonValue
     @Override
@@ -179,6 +180,11 @@ public class SegmentMetadataQuery extends BaseQuery<SegmentAnalysis>
     return analysisTypes.contains(AnalysisType.AGGREGATORS);
   }
 
+  public boolean hasQueryGranularity()
+  {
+    return analysisTypes.contains(AnalysisType.QUERYGRANULARITY);
+  }
+
   public boolean hasMinMax()
   {
     return analysisTypes.contains(AnalysisType.MINMAX);

processing/src/main/java/io/druid/segment/Metadata.java

@@ -20,6 +20,7 @@
 package io.druid.segment;
 
 import com.fasterxml.jackson.annotation.JsonProperty;
+import io.druid.granularity.QueryGranularity;
 import io.druid.query.aggregation.AggregatorFactory;
 
 import java.util.ArrayList;
@@ -41,6 +42,9 @@ public class Metadata
   @JsonProperty
   private AggregatorFactory[] aggregators;
 
+  @JsonProperty
+  private QueryGranularity queryGranularity;
+
   public Metadata()
   {
     container = new ConcurrentHashMap<>();
@@ -57,6 +61,17 @@ public class Metadata
     return this;
   }
 
+  public QueryGranularity getQueryGranularity()
+  {
+    return queryGranularity;
+  }
+
+  public Metadata setQueryGranularity(QueryGranularity queryGranularity)
+  {
+    this.queryGranularity = queryGranularity;
+    return this;
+  }
+
   public Metadata putAll(Map<String, Object> other)
   {
     if (other != null) {
@@ -96,17 +111,24 @@ public class Metadata
                                                    ? new ArrayList<AggregatorFactory[]>()
                                                    : null;
 
+    List<QueryGranularity> gransToMerge = new ArrayList<>();
+
     for (Metadata metadata : toBeMerged) {
       if (metadata != null) {
         foundSomeMetadata = true;
         if (aggregatorsToMerge != null) {
           aggregatorsToMerge.add(metadata.getAggregators());
         }
+
+        if (gransToMerge != null) {
+          gransToMerge.add(metadata.getQueryGranularity());
+        }
         mergedContainer.putAll(metadata.container);
       } else {
-        //if metadata and hence aggregators for some segment being merged are unknown then
+        //if metadata and hence aggregators and queryGranularity for some segment being merged are unknown then
-        //final merged segment should not have aggregators in the metadata
+        //final merged segment should not have same in metadata
         aggregatorsToMerge = null;
+        gransToMerge = null;
       }
     }
 
@@ -120,6 +142,11 @@ public class Metadata
     } else {
       result.setAggregators(overrideMergedAggregators);
     }
+
+    if (gransToMerge != null) {
+      result.setQueryGranularity(QueryGranularity.mergeQueryGranularities(gransToMerge));
+    }
+
     result.container.putAll(mergedContainer);
     return result;
 
@@ -141,7 +168,12 @@ public class Metadata
       return false;
     }
     // Probably incorrect - comparing Object[] arrays with Arrays.equals
-    return Arrays.equals(aggregators, metadata.aggregators);
+    if (!Arrays.equals(aggregators, metadata.aggregators)) {
+      return false;
+    }
+    return !(queryGranularity != null
+             ? !queryGranularity.equals(metadata.queryGranularity)
+             : metadata.queryGranularity != null);
 
   }
 
@@ -150,6 +182,7 @@ public class Metadata
   {
     int result = container.hashCode();
     result = 31 * result + (aggregators != null ? Arrays.hashCode(aggregators) : 0);
+    result = 31 * result + (queryGranularity != null ? queryGranularity.hashCode() : 0);
     return result;
   }
 
@@ -157,8 +190,10 @@ public class Metadata
   public String toString()
   {
     return "Metadata{" +
+
            "container=" + container +
            ", aggregators=" + Arrays.toString(aggregators) +
+           ", queryGranularity=" + queryGranularity +
            '}';
   }
 }

processing/src/main/java/io/druid/segment/incremental/IncrementalIndex.java

@@ -398,7 +398,9 @@ public abstract class IncrementalIndex<AggregatorType> implements Iterable<Row>,
     this.reportParseExceptions = reportParseExceptions;
     this.sortFacts = sortFacts;
 
-    this.metadata = new Metadata().setAggregators(getCombiningAggregators(metrics));
+    this.metadata = new Metadata()
+        .setAggregators(getCombiningAggregators(metrics))
+        .setQueryGranularity(this.gran);
 
     this.aggs = initAggs(metrics, rowSupplier, deserializeComplexMetrics);
     this.columnCapabilities = Maps.newHashMap();

processing/src/test/java/io/druid/granularity/QueryGranularityTest.java

@@ -20,10 +20,19 @@
 package io.druid.granularity;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
 import io.druid.jackson.DefaultObjectMapper;
-import org.joda.time.*;
+import org.joda.time.DateTime;
+import org.joda.time.DateTimeZone;
+import org.joda.time.Days;
+import org.joda.time.Hours;
+import org.joda.time.Minutes;
+import org.joda.time.Months;
+import org.joda.time.Period;
+import org.joda.time.Weeks;
+import org.joda.time.Years;
 import org.junit.Assert;
 import org.junit.Test;
 
@@ -698,6 +707,32 @@ public class QueryGranularityTest
     Assert.assertEquals(new DurationGranularity(15 * 60 * 1000, null), gran);
   }
 
+  @Test
+  public void testMerge()
+  {
+    Assert.assertNull(QueryGranularity.mergeQueryGranularities(null));
+    Assert.assertNull(QueryGranularity.mergeQueryGranularities(ImmutableList.<QueryGranularity>of()));
+    Assert.assertNull(QueryGranularity.mergeQueryGranularities(Lists.newArrayList(null, QueryGranularity.DAY)));
+    Assert.assertNull(QueryGranularity.mergeQueryGranularities(Lists.newArrayList(QueryGranularity.DAY, null)));
+    Assert.assertNull(
+        QueryGranularity.mergeQueryGranularities(
+            Lists.newArrayList(
+                QueryGranularity.DAY,
+                null,
+                QueryGranularity.DAY
+            )
+        )
+    );
+    Assert.assertNull(
+        QueryGranularity.mergeQueryGranularities(ImmutableList.of(QueryGranularity.ALL, QueryGranularity.DAY))
+    );
+
+    Assert.assertEquals(
+        QueryGranularity.ALL,
+        QueryGranularity.mergeQueryGranularities(ImmutableList.of(QueryGranularity.ALL, QueryGranularity.ALL))
+    );
+  }
+
   private void assertSame(List<DateTime> expected, Iterable<Long> actual)
   {
     Assert.assertEquals(expected.size(), Iterables.size(actual));

processing/src/test/java/io/druid/query/metadata/SegmentMetadataQueryQueryToolChestTest.java

@@ -85,6 +85,7 @@ public class SegmentMetadataQueryQueryToolChestTest
             )
         ), 71982,
         100,
+        null,
         null
     );
 
@@ -113,7 +114,8 @@ public class SegmentMetadataQueryQueryToolChestTest
         ImmutableMap.of(
             "foo", new LongSumAggregatorFactory("foo", "foo"),
             "baz", new DoubleSumAggregatorFactory("baz", "baz")
-        )
+        ),
+        null
     );
     final SegmentAnalysis analysis2 = new SegmentAnalysis(
         "id",
@@ -124,7 +126,8 @@ public class SegmentMetadataQueryQueryToolChestTest
         ImmutableMap.of(
             "foo", new LongSumAggregatorFactory("foo", "foo"),
             "bar", new DoubleSumAggregatorFactory("bar", "bar")
-        )
+        ),
+        null
     );
 
     Assert.assertEquals(
@@ -154,6 +157,7 @@ public class SegmentMetadataQueryQueryToolChestTest
         Maps.<String, ColumnAnalysis>newHashMap(),
         0,
         0,
+        null,
         null
     );
     final SegmentAnalysis analysis2 = new SegmentAnalysis(
@@ -165,7 +169,8 @@ public class SegmentMetadataQueryQueryToolChestTest
         ImmutableMap.of(
             "foo", new LongSumAggregatorFactory("foo", "foo"),
             "bar", new DoubleSumAggregatorFactory("bar", "bar")
-        )
+        ),
+        null
     );
 
     Assert.assertNull(mergeStrict(analysis1, analysis2).getAggregators());
@@ -187,6 +192,7 @@ public class SegmentMetadataQueryQueryToolChestTest
         Maps.<String, ColumnAnalysis>newHashMap(),
         0,
         0,
+        null,
         null
     );
     final SegmentAnalysis analysis2 = new SegmentAnalysis(
@@ -195,6 +201,7 @@ public class SegmentMetadataQueryQueryToolChestTest
         Maps.<String, ColumnAnalysis>newHashMap(),
         0,
         0,
+        null,
         null
     );
 
@@ -214,7 +221,8 @@ public class SegmentMetadataQueryQueryToolChestTest
         ImmutableMap.of(
             "foo", new LongSumAggregatorFactory("foo", "foo"),
             "bar", new DoubleSumAggregatorFactory("bar", "bar")
-        )
+        ),
+        null
     );
     final SegmentAnalysis analysis2 = new SegmentAnalysis(
         "id",
@@ -226,7 +234,8 @@ public class SegmentMetadataQueryQueryToolChestTest
             "foo", new LongSumAggregatorFactory("foo", "foo"),
             "bar", new DoubleMaxAggregatorFactory("bar", "bar"),
             "baz", new LongMaxAggregatorFactory("baz", "baz")
-        )
+        ),
+        null
     );
 
     final Map<String, AggregatorFactory> expectedLenient = Maps.newHashMap();

processing/src/test/java/io/druid/query/metadata/SegmentMetadataQueryTest.java

@@ -28,6 +28,7 @@ import com.google.common.collect.Maps;
 import com.google.common.util.concurrent.MoreExecutors;
 import com.metamx.common.guava.Sequences;
 import io.druid.common.utils.JodaUtils;
+import io.druid.granularity.QueryGranularity;
 import io.druid.jackson.DefaultObjectMapper;
 import io.druid.query.BySegmentResultValue;
 import io.druid.query.BySegmentResultValueClass;
@@ -179,6 +180,7 @@ public class SegmentMetadataQueryTest
             )
         ), mmap1 ? 71982 : 72755,
         1209,
+        null,
         null
     );
     expectedSegmentAnalysis2 = new SegmentAnalysis(
@@ -220,6 +222,7 @@ public class SegmentMetadataQueryTest
         // null_column will be included only for incremental index, which makes a little bigger result than expected
         ), mmap2 ? 71982 : 72755,
         1209,
+        null,
         null
     );
   }
@@ -266,6 +269,7 @@ public class SegmentMetadataQueryTest
         ),
         0,
         expectedSegmentAnalysis1.getNumRows() + expectedSegmentAnalysis2.getNumRows(),
+        null,
         null
     );
 
@@ -332,6 +336,7 @@ public class SegmentMetadataQueryTest
         ),
         0,
         expectedSegmentAnalysis1.getNumRows() + expectedSegmentAnalysis2.getNumRows(),
+        null,
         null
     );
 
@@ -447,6 +452,7 @@ public class SegmentMetadataQueryTest
         ),
         expectedSegmentAnalysis1.getSize() + expectedSegmentAnalysis2.getSize(),
         expectedSegmentAnalysis1.getNumRows() + expectedSegmentAnalysis2.getNumRows(),
+        null,
         null
     );
 
@@ -496,6 +502,7 @@ public class SegmentMetadataQueryTest
         ),
         0,
         expectedSegmentAnalysis1.getNumRows() + expectedSegmentAnalysis2.getNumRows(),
+        null,
         null
     );
 
@@ -556,7 +563,8 @@ public class SegmentMetadataQueryTest
         ),
         0,
         expectedSegmentAnalysis1.getNumRows() + expectedSegmentAnalysis2.getNumRows(),
-        expectedAggregators
+        expectedAggregators,
+        null
     );
 
     QueryToolChest toolChest = FACTORY.getToolchest();
@@ -592,6 +600,64 @@ public class SegmentMetadataQueryTest
     exec.shutdownNow();
   }
 
+
+  @Test
+  public void testSegmentMetadataQueryWithQueryGranularityMerge()
+  {
+    SegmentAnalysis mergedSegmentAnalysis = new SegmentAnalysis(
+        differentIds ? "merged" : "testSegment",
+        null,
+        ImmutableMap.of(
+            "placement",
+            new ColumnAnalysis(
+                ValueType.STRING.toString(),
+                false,
+                0,
+                0,
+                null,
+                null,
+                null
+            )
+        ),
+        0,
+        expectedSegmentAnalysis1.getNumRows() + expectedSegmentAnalysis2.getNumRows(),
+        null,
+        QueryGranularity.NONE
+    );
+
+    QueryToolChest toolChest = FACTORY.getToolchest();
+
+    ExecutorService exec = Executors.newCachedThreadPool();
+    QueryRunner myRunner = new FinalizeResultsQueryRunner<>(
+        toolChest.mergeResults(
+            FACTORY.mergeRunners(
+                MoreExecutors.sameThreadExecutor(),
+                Lists.<QueryRunner<SegmentAnalysis>>newArrayList(
+                    toolChest.preMergeQueryDecoration(runner1),
+                    toolChest.preMergeQueryDecoration(runner2)
+                )
+            )
+        ),
+        toolChest
+    );
+
+    TestHelper.assertExpectedObjects(
+        ImmutableList.of(mergedSegmentAnalysis),
+        myRunner.run(
+            Druids.newSegmentMetadataQueryBuilder()
+                  .dataSource("testing")
+                  .intervals("2013/2014")
+                  .toInclude(new ListColumnIncluderator(Arrays.asList("placement")))
+                  .analysisTypes(SegmentMetadataQuery.AnalysisType.QUERYGRANULARITY)
+                  .merge(true)
+                  .build(),
+            Maps.newHashMap()
+        ),
+        "failed SegmentMetadata merging query"
+    );
+    exec.shutdownNow();
+  }
+
   @Test
   public void testBySegmentResults()
   {

processing/src/test/java/io/druid/segment/IndexMergerTest.java

@@ -182,6 +182,11 @@ public class IndexMergerTest
         IncrementalIndexTest.getDefaultCombiningAggregatorFactories(),
         index.getMetadata().getAggregators()
     );
+
+    Assert.assertEquals(
+        QueryGranularity.NONE,
+        index.getMetadata().getQueryGranularity()
+    );
   }
 
   @Test
@@ -267,6 +272,7 @@ public class IndexMergerTest
             .setAggregators(
                 IncrementalIndexTest.getDefaultCombiningAggregatorFactories()
             )
+            .setQueryGranularity(QueryGranularity.NONE)
             .putAll(metadataElems),
         index.getMetadata()
     );

processing/src/test/java/io/druid/segment/MetadataTest.java

@@ -21,6 +21,7 @@ package io.druid.segment;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.common.collect.ImmutableList;
+import io.druid.granularity.QueryGranularity;
 import io.druid.jackson.DefaultObjectMapper;
 import io.druid.query.aggregation.AggregatorFactory;
 import io.druid.query.aggregation.DoubleMaxAggregatorFactory;
@@ -49,6 +50,7 @@ public class MetadataTest
             new LongSumAggregatorFactory("out", "in")
         };
     metadata.setAggregators(aggregators);
+    metadata.setQueryGranularity(QueryGranularity.ALL);
 
     Metadata other = jsonMapper.readValue(
         jsonMapper.writeValueAsString(metadata),
@@ -76,10 +78,12 @@ public class MetadataTest
     Metadata m1 = new Metadata();
     m1.put("k", "v");
     m1.setAggregators(aggs);
+    m1.setQueryGranularity(QueryGranularity.ALL);
 
     Metadata m2 = new Metadata();
     m2.put("k", "v");
     m2.setAggregators(aggs);
+    m2.setQueryGranularity(QueryGranularity.ALL);
 
     Metadata merged = new Metadata();
     merged.put("k", "v");
@@ -88,6 +92,7 @@ public class MetadataTest
             new LongMaxAggregatorFactory("n", "n")
         }
     );
+    merged.setQueryGranularity(QueryGranularity.ALL);
     Assert.assertEquals(merged, Metadata.merge(ImmutableList.of(m1, m2), null));
 
     //merge check with one metadata being null
@@ -97,6 +102,7 @@ public class MetadataTest
     metadataToBeMerged.add(null);
 
     merged.setAggregators(null);
+    merged.setQueryGranularity(null);
     Assert.assertEquals(merged, Metadata.merge(metadataToBeMerged, null));
 
     //merge check with client explicitly providing merged aggregators
@@ -110,6 +116,7 @@ public class MetadataTest
         Metadata.merge(metadataToBeMerged, explicitAggs)
     );
 
+    merged.setQueryGranularity(QueryGranularity.ALL);
     Assert.assertEquals(
         merged,
         Metadata.merge(ImmutableList.of(m1, m2), explicitAggs)