Merge branch 'master' into new-schema

Conflicts:
	indexing-hadoop/src/main/java/io/druid/indexer/DetermineHashedPartitionsJob.java
	indexing-service/src/main/java/io/druid/indexing/common/task/RealtimeIndexTask.java
	indexing-service/src/test/java/io/druid/indexing/common/task/TaskSerdeTest.java
	processing/src/test/java/io/druid/segment/TestIndex.java
	server/src/main/java/io/druid/segment/realtime/RealtimeManager.java
	server/src/main/java/io/druid/segment/realtime/plumber/RealtimePlumberSchool.java

build.sh

@@ -30,4 +30,4 @@ echo "For examples, see: "
 echo " "
 ls -1 examples/*/*sh
 echo " "
-echo "See also http://druid.io/docs/0.6.61"
+echo "See also http://druid.io/docs/0.6.69"

cassandra-storage/pom.xml

@@ -28,7 +28,7 @@
     <parent>
         <groupId>io.druid</groupId>
         <artifactId>druid</artifactId>
-        <version>0.6.63-SNAPSHOT</version>
+        <version>0.6.70-SNAPSHOT</version>
     </parent>
 
     <dependencies>

common/pom.xml

@@ -28,7 +28,7 @@
     <parent>
         <groupId>io.druid</groupId>
         <artifactId>druid</artifactId>
-        <version>0.6.63-SNAPSHOT</version>
+        <version>0.6.70-SNAPSHOT</version>
     </parent>
 
     <dependencies>

common/src/main/java/io/druid/concurrent/Execs.java

@@ -22,11 +22,13 @@ package io.druid.concurrent;
 import com.google.common.util.concurrent.ThreadFactoryBuilder;
 
 import java.util.concurrent.ArrayBlockingQueue;
+import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.RejectedExecutionException;
 import java.util.concurrent.RejectedExecutionHandler;
 import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.SynchronousQueue;
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
@@ -60,25 +62,29 @@ public class Execs
    * @param capacity maximum capacity after which the executorService will block on accepting new tasks
    * @return ExecutorService which blocks accepting new tasks when the capacity reached
    */
-  public static ExecutorService newBlockingSingleThreaded(String nameFormat, int capacity)
+  public static ExecutorService newBlockingSingleThreaded(final String nameFormat, final int capacity)
   {
-    return new ThreadPoolExecutor(
-        1, 1,
-        0L, TimeUnit.MILLISECONDS,
-        new ArrayBlockingQueue<Runnable>(capacity), makeThreadFactory(nameFormat)
-        , new RejectedExecutionHandler()
-    {
-      @Override
-      public void rejectedExecution(Runnable r, ThreadPoolExecutor executor)
-      {
-        try {
-          ((ArrayBlockingQueue) executor.getQueue()).put(r);
-        }
-        catch (InterruptedException e) {
-          throw new RejectedExecutionException("Got Interrupted while adding to the Queue");
-        }
-      }
+    final BlockingQueue<Runnable> queue;
+    if (capacity > 0) {
+      queue = new ArrayBlockingQueue<>(capacity);
+    } else {
+      queue = new SynchronousQueue<>();
     }
+    return new ThreadPoolExecutor(
+        1, 1, 0L, TimeUnit.MILLISECONDS, queue, makeThreadFactory(nameFormat),
+        new RejectedExecutionHandler()
+        {
+          @Override
+          public void rejectedExecution(Runnable r, ThreadPoolExecutor executor)
+          {
+            try {
+              executor.getQueue().put(r);
+            }
+            catch (InterruptedException e) {
+              throw new RejectedExecutionException("Got Interrupted while adding to the Queue");
+            }
+          }
+        }
     );
   }
 }

common/src/test/java/io/druid/concurrent/ExecsTest.java

@@ -20,6 +20,8 @@
 package io.druid.concurrent;
 
 import com.google.common.base.Throwables;
+import com.google.common.util.concurrent.ThreadFactoryBuilder;
+import com.metamx.common.logger.Logger;
 import org.junit.Assert;
 import org.junit.Test;
 
@@ -30,23 +32,46 @@ import java.util.concurrent.atomic.AtomicInteger;
 
 public class ExecsTest
 {
+  private static final Logger log = new Logger(ExecsTest.class);
+
   @Test
-  public void testBlockingExecutorService() throws Exception
+  public void testBlockingExecutorServiceZeroCapacity() throws Exception
   {
-    final int capacity = 3;
-    final ExecutorService blockingExecutor = Execs.newBlockingSingleThreaded("test%d", capacity);
-    final CountDownLatch queueFullSignal = new CountDownLatch(capacity + 1);
-    final CountDownLatch taskCompletedSignal = new CountDownLatch(2 * capacity);
+    runTest(0);
+  }
+
+  @Test
+  public void testBlockingExecutorServiceOneCapacity() throws Exception
+  {
+    runTest(1);
+  }
+
+  @Test
+  public void testBlockingExecutorServiceThreeCapacity() throws Exception
+  {
+    runTest(3);
+  }
+
+  private static void runTest(final int capacity) throws Exception
+  {
+    final int nTasks = (capacity + 1) * 3;
+    final ExecutorService blockingExecutor = Execs.newBlockingSingleThreaded("ExecsTest-Blocking-%d", capacity);
+    final CountDownLatch queueShouldBeFullSignal = new CountDownLatch(capacity + 1);
+    final CountDownLatch taskCompletedSignal = new CountDownLatch(nTasks);
     final CountDownLatch taskStartSignal = new CountDownLatch(1);
     final AtomicInteger producedCount = new AtomicInteger();
     final AtomicInteger consumedCount = new AtomicInteger();
-    ExecutorService producer = Executors.newSingleThreadExecutor();
+    final ExecutorService producer = Executors.newSingleThreadExecutor(
+        new ThreadFactoryBuilder().setNameFormat(
+            "ExecsTest-Producer-%d"
+        ).build()
+    );
     producer.submit(
         new Runnable()
         {
           public void run()
           {
-            for (int i = 0; i < 2 * capacity; i++) {
+            for (int i = 0; i < nTasks; i++) {
               final int taskID = i;
               System.out.println("Produced task" + taskID);
               blockingExecutor.submit(
@@ -55,7 +80,7 @@ public class ExecsTest
                     @Override
                     public void run()
                     {
-                      System.out.println("Starting task" + taskID);
+                      log.info("Starting task: %s", taskID);
                       try {
                         taskStartSignal.await();
                         consumedCount.incrementAndGet();
@@ -64,29 +89,31 @@ public class ExecsTest
                       catch (Exception e) {
                         throw Throwables.propagate(e);
                       }
-                      System.out.println("Completed task" + taskID);
+                      log.info("Completed task: %s", taskID);
                     }
                   }
               );
               producedCount.incrementAndGet();
-              queueFullSignal.countDown();
+              queueShouldBeFullSignal.countDown();
             }
           }
         }
     );
 
-    queueFullSignal.await();
-    // verify that the producer blocks
+    queueShouldBeFullSignal.await();
+    // Verify that the producer blocks. I don't think it's possible to be sure that the producer is blocking (since
+    // it could be doing nothing for any reason). But waiting a short period of time and checking that it hasn't done
+    // anything should hopefully be sufficient.
+    Thread.sleep(500);
     Assert.assertEquals(capacity + 1, producedCount.get());
     // let the tasks run
     taskStartSignal.countDown();
     // wait until all tasks complete
     taskCompletedSignal.await();
     // verify all tasks consumed
-    Assert.assertEquals(2 * capacity, consumedCount.get());
+    Assert.assertEquals(nTasks, consumedCount.get());
     // cleanup
     blockingExecutor.shutdown();
     producer.shutdown();
-
   }
 }

docs/content/Aggregations.md

@@ -82,3 +82,13 @@ All JavaScript functions must return numerical values.
   "fnReset"     : "function()                   { return 10; }"
 }
 ```
+
+### Complex aggregators
+
+#### `hyperUnique` aggregator
+
+`hyperUnique` uses [Hyperloglog](http://algo.inria.fr/flajolet/Publications/FlFuGaMe07.pdf) to compute the estimated cardinality of a dimension.
+
+```json
+{ "type" : "hyperUnique", "name" : <output_name>, "fieldName" : <metric_name> }
+```

docs/content/Broker-Config.md

@@ -26,6 +26,11 @@ druid.service=broker
 druid.port=8080
 
 druid.zk.service.host=localhost
+
+# Change these to make Druid faster
+druid.processing.buffer.sizeBytes=100000000
+druid.processing.numThreads=1
+
 ```
 
 Production Configs

docs/content/DataSource.md

@@ -0,0 +1,25 @@
+---
+layout: doc_page
+---
+A data source is the Druid equivalent of a database table. However, a query can also masquerade as a data source, providing subquery-like functionality. Query data sources are currently only supported by [GroupBy](GroupByQuery.html) queries.
+
+### Table Data Source
+The table data source the most common type. It's represented by a string, or by the full structure:
+
+```json
+{
+	"type": "table",
+	"name": <string_value>
+}
+```
+
+### Query Data Source
+```json
+{
+	"type": "query",
+	"query": {
+		"type": "groupBy",
+		...
+	}
+}
+```

docs/content/Examples.md

@@ -19,13 +19,13 @@ Clone Druid and build it:
 git clone https://github.com/metamx/druid.git druid
 cd druid
 git fetch --tags
-git checkout druid-0.6.61
+git checkout druid-0.6.69
 ./build.sh
 ```
 
 ### Downloading the DSK (Druid Standalone Kit)
 
-[Download](http://static.druid.io/artifacts/releases/druid-services-0.6.61-bin.tar.gz) a stand-alone tarball and run it:
+[Download](http://static.druid.io/artifacts/releases/druid-services-0.6.69-bin.tar.gz) a stand-alone tarball and run it:
 
 ``` bash
 tar -xzf druid-services-0.X.X-bin.tar.gz

docs/content/GroupByQuery.md

@@ -48,7 +48,7 @@ There are 9 main parts to a groupBy query:
 |property|description|required?|
 |--------|-----------|---------|
 |queryType|This String should always be "groupBy"; this is the first thing Druid looks at to figure out how to interpret the query|yes|
-|dataSource|A String defining the data source to query, very similar to a table in a relational database|yes|
+|dataSource|A String defining the data source to query, very similar to a table in a relational database, or a [DataSource](DataSource.html) structure.|yes|
 |dimensions|A JSON list of dimensions to do the groupBy over|yes|
 |orderBy|See [OrderBy](OrderBy.html).|no|
 |having|See [Having](Having.html).|no|

docs/content/Indexing-Service-Config.md

@@ -66,7 +66,7 @@ druid.host=#{IP_ADDR}:8080
 druid.port=8080
 druid.service=druid/prod/indexer
 
-druid.extensions.coordinates=["io.druid.extensions:druid-s3-extensions:0.6.61"]
+druid.extensions.coordinates=["io.druid.extensions:druid-s3-extensions:0.6.69"]
 
 druid.zk.service.host=#{ZK_IPs}
 druid.zk.paths.base=/druid/prod
@@ -115,7 +115,7 @@ druid.host=#{IP_ADDR}:8080
 druid.port=8080
 druid.service=druid/prod/worker
 
-druid.extensions.coordinates=["io.druid.extensions:druid-s3-extensions:0.6.61","io.druid.extensions:druid-kafka-seven:0.6.61"]
+druid.extensions.coordinates=["io.druid.extensions:druid-s3-extensions:0.6.69","io.druid.extensions:druid-kafka-seven:0.6.69"]
 
 druid.zk.service.host=#{ZK_IPs}
 druid.zk.paths.base=/druid/prod

docs/content/Post-aggregations.md

@@ -64,6 +64,31 @@ Example JavaScript aggregator:
   "function": "function(delta, total) { return 100 * Math.abs(delta) / total; }"
 }
 ```
+### `hyperUniqueCardinality` post-aggregator
+
+The hyperUniqueCardinality post aggregator is used to wrap a hyperUnique object such that it can be used in post aggregations.
+
+```json
+{ "type"  : "hyperUniqueCardinality", "fieldName"  : <the name field value of the hyperUnique aggregator>}
+```
+
+It can be used in a sample calculation as so:
+
+```json
+  "aggregations" : [{
+    {"type" : "count", "name" : "rows"},
+    {"type" : "hyperUnique", "name" : "unique_users", "fieldName" : "uniques"}
+  }],
+  "postAggregations" : {
+    "type"   : "arithmetic",
+    "name"   : "average_users_per_row",
+    "fn"     : "/",
+    "fields" : [
+      { "type" : "hyperUniqueCardinality", "fieldName" : "unique_users" },
+      { "type" : "fieldAccess", "name" : "rows", "fieldName" : "rows" }
+    ]
+  }
+```
 
 
 ### Example Usage
@@ -98,4 +123,4 @@ The format of the query JSON is as follows:
   ...
 }
 
-```
+```

docs/content/Realtime-Config.md

@@ -27,7 +27,7 @@ druid.host=localhost
 druid.service=realtime
 druid.port=8083
 
-druid.extensions.coordinates=["io.druid.extensions:druid-kafka-seven:0.6.61"]
+druid.extensions.coordinates=["io.druid.extensions:druid-kafka-seven:0.6.69"]
 
 
 druid.zk.service.host=localhost
@@ -76,7 +76,7 @@ druid.host=#{IP_ADDR}:8080
 druid.port=8080
 druid.service=druid/prod/realtime
 
-druid.extensions.coordinates=["io.druid.extensions:druid-s3-extensions:0.6.61","io.druid.extensions:druid-kafka-seven:0.6.61"]
+druid.extensions.coordinates=["io.druid.extensions:druid-s3-extensions:0.6.69","io.druid.extensions:druid-kafka-seven:0.6.69"]
 
 druid.zk.service.host=#{ZK_IPs}
 druid.zk.paths.base=/druid/prod

docs/content/Tasks.md

@@ -152,10 +152,7 @@ The indexing service can also run real-time tasks. These tasks effectively trans
     "intermediatePersistPeriod": "PT10m"
   },
   "windowPeriod": "PT10m",
-  "segmentGranularity": "hour",
-  "rejectionPolicy": {
-    "type": "messageTime"
-  }
+  "segmentGranularity": "hour"
 }
 ```
 

docs/content/Tutorial:-A-First-Look-at-Druid.md

@@ -49,7 +49,7 @@ There are two ways to setup Druid: download a tarball, or [Build From Source](Bu
 
 ### Download a Tarball
 
-We've built a tarball that contains everything you'll need. You'll find it [here](http://static.druid.io/artifacts/releases/druid-services-0.6.61-bin.tar.gz). Download this file to a directory of your choosing.
+We've built a tarball that contains everything you'll need. You'll find it [here](http://static.druid.io/artifacts/releases/druid-services-0.6.69-bin.tar.gz). Download this file to a directory of your choosing.
 
 You can extract the awesomeness within by issuing:
 
@@ -60,7 +60,7 @@ tar -zxvf druid-services-*-bin.tar.gz
 Not too lost so far right? That's great! If you cd into the directory:
 
 ```
-cd druid-services-0.6.61
+cd druid-services-0.6.69
 ```
 
 You should see a bunch of files:

docs/content/Tutorial:-Loading-Your-Data-Part-2.md

@@ -160,13 +160,15 @@ You should be comfortable starting Druid nodes at this point. If not, it may be
         "segmentGranularity": "hour",
         "basePersistDirectory": "\/tmp\/realtime\/basePersist",
         "rejectionPolicy": {
-          "type": "none"
+          "type": "test"
         }
       }
     }
   ]
   ```
 
+Note: This config uses a "test" rejection policy which will accept all events and timely hand off, however, we strongly recommend you do not use this in production. Using this rejection policy, segments for events for the same time range will be overridden.
+
 3. Let's copy and paste some data into the Kafka console producer
 
   ```json

docs/content/Tutorial:-The-Druid-Cluster.md

@@ -13,7 +13,7 @@ In this tutorial, we will set up other types of Druid nodes and external depende
 
 If you followed the first tutorial, you should already have Druid downloaded. If not, let's go back and do that first.
 
-You can download the latest version of druid [here](http://static.druid.io/artifacts/releases/druid-services-0.6.61-bin.tar.gz)
+You can download the latest version of druid [here](http://static.druid.io/artifacts/releases/druid-services-0.6.69-bin.tar.gz)
 
 and untar the contents within by issuing:
 
@@ -149,7 +149,7 @@ druid.port=8081
 
 druid.zk.service.host=localhost
 
-druid.extensions.coordinates=["io.druid.extensions:druid-s3-extensions:0.6.61"]
+druid.extensions.coordinates=["io.druid.extensions:druid-s3-extensions:0.6.69"]
 
 # Dummy read only AWS account (used to download example data)
 druid.s3.secretKey=QyyfVZ7llSiRg6Qcrql1eEUG7buFpAK6T6engr1b
@@ -240,7 +240,7 @@ druid.port=8083
 
 druid.zk.service.host=localhost
 
-druid.extensions.coordinates=["io.druid.extensions:druid-examples:0.6.61","io.druid.extensions:druid-kafka-seven:0.6.61"]
+druid.extensions.coordinates=["io.druid.extensions:druid-examples:0.6.69","io.druid.extensions:druid-kafka-seven:0.6.69"]
 
 # Change this config to db to hand off to the rest of the Druid cluster
 druid.publish.type=noop
@@ -251,6 +251,9 @@ druid.publish.type=noop
 # druid.db.connector.password=diurd
 
 druid.processing.buffer.sizeBytes=100000000
+druid.processing.numThreads=1
+
+druid.monitoring.monitors=["io.druid.segment.realtime.RealtimeMetricsMonitor"]
 ```
 
 Next Steps

docs/content/Tutorial:-Webstream.md

@@ -37,7 +37,7 @@ There are two ways to setup Druid: download a tarball, or [Build From Source](Bu
 
 h3. Download a Tarball
 
-We've built a tarball that contains everything you'll need. You'll find it [here](http://static.druid.io/artifacts/releases/druid-services-0.6.61-bin.tar.gz)
+We've built a tarball that contains everything you'll need. You'll find it [here](http://static.druid.io/artifacts/releases/druid-services-0.6.69-bin.tar.gz)
 Download this file to a directory of your choosing.
 You can extract the awesomeness within by issuing:
 
@@ -48,7 +48,7 @@ tar zxvf druid-services-*-bin.tar.gz
 Not too lost so far right? That's great! If you cd into the directory:
 
 ```
-cd druid-services-0.6.61
+cd druid-services-0.6.69
 ```
 
 You should see a bunch of files:

docs/content/Twitter-Tutorial.textile

@@ -9,7 +9,7 @@ There are two ways to setup Druid: download a tarball, or build it from source.
 
 h3. Download a Tarball
 
-We've built a tarball that contains everything you'll need. You'll find it "here":http://static.druid.io/artifacts/releases/druid-services-0.6.61-bin.tar.gz.
+We've built a tarball that contains everything you'll need. You'll find it "here":http://static.druid.io/artifacts/releases/druid-services-0.6.69-bin.tar.gz.
 Download this bad boy to a directory of your choosing.
 
 You can extract the awesomeness within by issuing:

examples/bin/examples/indexing/wikipedia.spec

@@ -53,7 +53,7 @@
       "segmentGranularity": "hour",
       "basePersistDirectory": "\/tmp\/realtime\/basePersist",
       "rejectionPolicy": {
-        "type": "messageTime"
+        "type": "test"
       }
     }
   }

examples/bin/examples/rabbitmq/rabbitmq_realtime.spec

@@ -43,6 +43,6 @@
         "windowPeriod" : "PT5m",
         "segmentGranularity":"hour",
         "basePersistDirectory" : "/tmp/realtime/basePersist",
-        "rejectionPolicy": { "type": "messageTime" }
+        "rejectionPolicy": { "type": "test" }
     }
 }]

examples/bin/run_example_server.sh

@@ -55,8 +55,6 @@ JAVA_ARGS="${JAVA_ARGS} -Ddruid.realtime.specFile=${SPEC_FILE}"
 
 DRUID_CP=${EXAMPLE_LOC}
 #For a pull
-DRUID_CP=${DRUID_CP}:`ls ${SCRIPT_DIR}/../target/druid-examples-*-selfcontained.jar`
-DRUID_CP=${DRUID_CP}:`ls ${SCRIPT_DIR}/../../services/target/druid-services-*-selfcontained.jar`
 DRUID_CP=${DRUID_CP}:${SCRIPT_DIR}/../config/realtime
 #For the kit
 DRUID_CP=${DRUID_CP}:${SCRIPT_DIR}/lib/*

examples/config/broker/runtime.properties

@@ -2,4 +2,8 @@ druid.host=localhost
 druid.service=broker
 druid.port=8080
 
-druid.zk.service.host=localhost
+druid.zk.service.host=localhost
+
+# Change these to make Druid faster
+druid.processing.buffer.sizeBytes=100000000
+druid.processing.numThreads=1

examples/config/historical/runtime.properties

@@ -4,7 +4,7 @@ druid.port=8081
 
 druid.zk.service.host=localhost
 
-druid.extensions.coordinates=["io.druid.extensions:druid-s3-extensions:0.6.61"]
+druid.extensions.coordinates=["io.druid.extensions:druid-s3-extensions:0.6.69"]
 
 # Dummy read only AWS account (used to download example data)
 druid.s3.secretKey=QyyfVZ7llSiRg6Qcrql1eEUG7buFpAK6T6engr1b

examples/config/realtime/runtime.properties

@@ -4,7 +4,7 @@ druid.port=8083
 
 druid.zk.service.host=localhost
 
-druid.extensions.coordinates=["io.druid.extensions:druid-examples:0.6.61","io.druid.extensions:druid-kafka-seven:0.6.61","io.druid.extensions:druid-rabbitmq:0.6.61"]
+druid.extensions.coordinates=["io.druid.extensions:druid-examples:0.6.69","io.druid.extensions:druid-kafka-seven:0.6.69","io.druid.extensions:druid-rabbitmq:0.6.69"]
 
 # Change this config to db to hand off to the rest of the Druid cluster
 druid.publish.type=noop
@@ -16,3 +16,5 @@ druid.publish.type=noop
 
 druid.processing.buffer.sizeBytes=100000000
 druid.processing.numThreads=1
+
+druid.monitoring.monitors=["io.druid.segment.realtime.RealtimeMetricsMonitor"]

examples/pom.xml

@@ -28,7 +28,7 @@
     <parent>
         <groupId>io.druid</groupId>
         <artifactId>druid</artifactId>
-        <version>0.6.63-SNAPSHOT</version>
+        <version>0.6.70-SNAPSHOT</version>
     </parent>
 
     <dependencies>

hdfs-storage/pom.xml

@@ -28,7 +28,7 @@
     <parent>
         <groupId>io.druid</groupId>
         <artifactId>druid</artifactId>
-        <version>0.6.63-SNAPSHOT</version>
+        <version>0.6.70-SNAPSHOT</version>
     </parent>
 
     <dependencies>

hll/pom.xml

@@ -28,7 +28,7 @@
     <parent>
         <groupId>io.druid</groupId>
         <artifactId>druid</artifactId>
-        <version>0.6.63-SNAPSHOT</version>
+        <version>0.6.70-SNAPSHOT</version>
     </parent>
 
     <dependencies>

indexing-hadoop/pom.xml

@@ -28,7 +28,7 @@
     <parent>
         <groupId>io.druid</groupId>
         <artifactId>druid</artifactId>
-        <version>0.6.63-SNAPSHOT</version>
+        <version>0.6.70-SNAPSHOT</version>
     </parent>
 
     <dependencies>
@@ -97,11 +97,6 @@
             <artifactId>junit</artifactId>
             <scope>test</scope>
         </dependency>
-      <dependency>
-        <groupId>com.clearspring.analytics</groupId>
-        <artifactId>stream</artifactId>
-        <version>2.5.2</version>
-      </dependency>
     </dependencies>
 
     <build>

indexing-hadoop/src/main/java/io/druid/indexer/DetermineHashedPartitionsJob.java

@@ -19,8 +19,6 @@
 
 package io.druid.indexer;
 
-import com.clearspring.analytics.stream.cardinality.CardinalityMergeException;
-import com.clearspring.analytics.stream.cardinality.HyperLogLog;
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.google.common.base.Optional;
 import com.google.common.base.Throwables;
@@ -36,6 +34,7 @@ import io.druid.data.input.InputRow;
 import io.druid.data.input.Rows;
 import io.druid.granularity.QueryGranularity;
 import io.druid.segment.indexing.granularity.UniformGranularitySpec;
+import io.druid.query.aggregation.hyperloglog.HyperLogLogCollector;
 import io.druid.timeline.partition.HashBasedNumberedShardSpec;
 import io.druid.timeline.partition.NoneShardSpec;
 import org.apache.hadoop.conf.Configuration;
@@ -56,6 +55,7 @@ import org.joda.time.Interval;
 
 import java.io.IOException;
 import java.io.OutputStream;
+import java.nio.ByteBuffer;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -67,7 +67,6 @@ public class DetermineHashedPartitionsJob implements Jobby
 {
   private static final int MAX_SHARDS = 128;
   private static final Logger log = new Logger(DetermineHashedPartitionsJob.class);
-  private static final int HYPER_LOG_LOG_BIT_SIZE = 20;
   private final HadoopDruidIndexerConfig config;
 
   public DetermineHashedPartitionsJob(
@@ -99,8 +98,8 @@ public class DetermineHashedPartitionsJob implements Jobby
       groupByJob.setOutputKeyClass(NullWritable.class);
       groupByJob.setOutputValueClass(NullWritable.class);
       groupByJob.setOutputFormatClass(SequenceFileOutputFormat.class);
-      if(!config.getSegmentGranularIntervals().isPresent()){
-      groupByJob.setNumReduceTasks(1);
+      if (!config.getSegmentGranularIntervals().isPresent()) {
+        groupByJob.setNumReduceTasks(1);
       }
       JobHelper.setupClasspath(config, groupByJob);
 
@@ -201,7 +200,7 @@ public class DetermineHashedPartitionsJob implements Jobby
   {
     private static HashFunction hashFunction = Hashing.murmur3_128();
     private QueryGranularity rollupGranularity = null;
-    private Map<Interval, HyperLogLog> hyperLogLogs;
+    private Map<Interval, HyperLogLogCollector> hyperLogLogs;
     private HadoopDruidIndexerConfig config;
     private boolean determineIntervals;
 
@@ -215,9 +214,9 @@ public class DetermineHashedPartitionsJob implements Jobby
       Optional<Set<Interval>> intervals = config.getSegmentGranularIntervals();
       if (intervals.isPresent()) {
         determineIntervals = false;
-        final ImmutableMap.Builder<Interval, HyperLogLog> builder = ImmutableMap.builder();
+        final ImmutableMap.Builder<Interval, HyperLogLogCollector> builder = ImmutableMap.builder();
         for (final Interval bucketInterval : intervals.get()) {
-          builder.put(bucketInterval, new HyperLogLog(HYPER_LOG_LOG_BIT_SIZE));
+          builder.put(bucketInterval, HyperLogLogCollector.makeLatestCollector());
         }
         hyperLogLogs = builder.build();
       } else {
@@ -245,7 +244,7 @@ public class DetermineHashedPartitionsJob implements Jobby
                          .bucket(new DateTime(inputRow.getTimestampFromEpoch()));
 
         if (!hyperLogLogs.containsKey(interval)) {
-          hyperLogLogs.put(interval, new HyperLogLog(HYPER_LOG_LOG_BIT_SIZE));
+          hyperLogLogs.put(interval, HyperLogLogCollector.makeLatestCollector());
         }
       } else {
         final Optional<Interval> maybeInterval = config.getGranularitySpec()
@@ -257,9 +256,9 @@ public class DetermineHashedPartitionsJob implements Jobby
         interval = maybeInterval.get();
       }
       hyperLogLogs.get(interval)
-                  .offerHashed(
+                  .add(
                       hashFunction.hashBytes(HadoopDruidIndexerConfig.jsonMapper.writeValueAsBytes(groupKey))
-                                  .asLong()
+                                  .asBytes()
                   );
     }
 
@@ -272,10 +271,10 @@ public class DetermineHashedPartitionsJob implements Jobby
         map(context.getCurrentKey(), context.getCurrentValue(), context);
       }
 
-      for (Map.Entry<Interval, HyperLogLog> entry : hyperLogLogs.entrySet()) {
+      for (Map.Entry<Interval, HyperLogLogCollector> entry : hyperLogLogs.entrySet()) {
         context.write(
             new LongWritable(entry.getKey().getStartMillis()),
-            new BytesWritable(entry.getValue().getBytes())
+            new BytesWritable(entry.getValue().toByteArray())
         );
       }
       cleanup(context);
@@ -303,15 +302,9 @@ public class DetermineHashedPartitionsJob implements Jobby
         Context context
     ) throws IOException, InterruptedException
     {
-      HyperLogLog aggregate = new HyperLogLog(HYPER_LOG_LOG_BIT_SIZE);
+      HyperLogLogCollector aggregate = HyperLogLogCollector.makeLatestCollector();
       for (BytesWritable value : values) {
-        HyperLogLog logValue = HyperLogLog.Builder.build(getDataBytes(value));
-        try {
-          aggregate.addAll(logValue);
-        }
-        catch (CardinalityMergeException e) {
-          e.printStackTrace(); // TODO: check for better handling
-        }
+        aggregate.fold(ByteBuffer.wrap(value.getBytes(), 0, value.getLength()));
       }
       Interval interval = config.getGranularitySpec().getSegmentGranularity().bucket(new DateTime(key.get()));
       intervals.add(interval);
@@ -327,7 +320,7 @@ public class DetermineHashedPartitionsJob implements Jobby
             }
         ).writeValue(
             out,
-            aggregate.cardinality()
+            new Double(aggregate.estimateCardinality()).longValue()
         );
       }
       finally {

indexing-hadoop/src/main/java/io/druid/indexer/HadoopDriverConfig.java

@@ -23,7 +23,6 @@ import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.google.common.collect.ImmutableMap;
-import com.google.common.io.Files;
 import io.druid.indexer.partitions.HashedPartitionsSpec;
 import io.druid.indexer.partitions.PartitionsSpec;
 import io.druid.segment.indexing.DriverConfig;
@@ -37,7 +36,6 @@ import java.util.Map;
 @JsonTypeName("hadoop")
 public class HadoopDriverConfig implements DriverConfig
 {
-  private static final String defaultWorkingPath = Files.createTempDir().getPath();
   private static final PartitionsSpec defaultPartitionsSpec = HashedPartitionsSpec.makeDefaultHashedPartitionsSpec();
   private static final Map<DateTime, List<HadoopyShardSpec>> defaultShardSpecs = ImmutableMap.<DateTime, List<HadoopyShardSpec>>of();
   private static final int defaultRowFlushBoundary = 80000;
@@ -45,7 +43,7 @@ public class HadoopDriverConfig implements DriverConfig
   public static HadoopDriverConfig makeDefaultDriverConfig()
   {
     return new HadoopDriverConfig(
-        defaultWorkingPath,
+        null,
         new DateTime().toString(),
         defaultPartitionsSpec,
         defaultShardSpecs,
@@ -80,7 +78,7 @@ public class HadoopDriverConfig implements DriverConfig
       final @JsonProperty("ignoreInvalidRows") boolean ignoreInvalidRows
   )
   {
-    this.workingPath = workingPath == null ? defaultWorkingPath : workingPath;
+    this.workingPath = workingPath == null ? null : workingPath;
     this.version = version == null ? new DateTime().toString() : version;
     this.partitionsSpec = partitionsSpec == null ? defaultPartitionsSpec : partitionsSpec;
     this.shardSpecs = shardSpecs == null ? defaultShardSpecs : shardSpecs;

indexing-service/pom.xml

@@ -28,7 +28,7 @@
     <parent>
         <groupId>io.druid</groupId>
         <artifactId>druid</artifactId>
-        <version>0.6.63-SNAPSHOT</version>
+        <version>0.6.70-SNAPSHOT</version>
     </parent>
 
     <dependencies>

indexing-service/src/main/java/io/druid/indexing/common/task/HadoopIndexTask.java

@@ -283,7 +283,7 @@ public class HadoopIndexTask extends AbstractTask
 
       Jobby job = new HadoopDruidDetermineConfigurationJob(config);
 
-      log.info("Starting a hadoop index generator job...");
+      log.info("Starting a hadoop determine configuration job...");
       if (job.run()) {
         return HadoopDruidIndexerConfig.jsonMapper.writeValueAsString(config.getSchema());
       }

indexing-service/src/main/java/io/druid/indexing/overlord/IndexerDBCoordinator.java

@@ -90,7 +90,7 @@ public class IndexerDBCoordinator
             final ResultIterator<Map<String, Object>> dbSegments =
                 handle.createQuery(
                     String.format(
-                        "SELECT payload FROM %s WHERE used = 1 AND dataSource = :dataSource",
+                        "SELECT payload FROM %s WHERE used = true AND dataSource = :dataSource",
                         dbTables.getSegmentsTable()
                     )
                 )
@@ -304,8 +304,8 @@ public class IndexerDBCoordinator
             return handle.createQuery(
                 String.format(
                     DbConnector.isPostgreSQL(handle)?
-                        "SELECT payload FROM %s WHERE dataSource = :dataSource and start >= :start and \"end\" <= :end and used = 0":
-                        "SELECT payload FROM %s WHERE dataSource = :dataSource and start >= :start and end <= :end and used = 0",
+                        "SELECT payload FROM %s WHERE dataSource = :dataSource and start >= :start and \"end\" <= :end and used = false":
+                        "SELECT payload FROM %s WHERE dataSource = :dataSource and start >= :start and end <= :end and used = false",
                     dbTables.getSegmentsTable()
                 )
             )

indexing-service/src/main/java/io/druid/indexing/overlord/ThreadPoolTaskRunner.java

@@ -38,6 +38,7 @@ import io.druid.indexing.common.TaskToolboxFactory;
 import io.druid.indexing.common.task.Task;
 import io.druid.query.NoopQueryRunner;
 import io.druid.query.Query;
+import io.druid.query.TableDataSource;
 import io.druid.query.QueryRunner;
 import io.druid.query.QuerySegmentWalker;
 import io.druid.query.SegmentDescriptor;
@@ -152,10 +153,17 @@ public class ThreadPoolTaskRunner implements TaskRunner, QuerySegmentWalker
   private <T> QueryRunner<T> getQueryRunnerImpl(Query<T> query)
   {
     QueryRunner<T> queryRunner = null;
+    String queryDataSource;
+    try {
+        queryDataSource = ((TableDataSource)query.getDataSource()).getName();
+    }
+    catch (ClassCastException e) {
+        throw new IllegalArgumentException("Subqueries are not welcome here");
+    }
 
     for (final ThreadPoolTaskRunnerWorkItem taskRunnerWorkItem : ImmutableList.copyOf(runningItems)) {
       final Task task = taskRunnerWorkItem.getTask();
-      if (task.getDataSource().equals(query.getDataSource())) {
+      if (task.getDataSource().equals(queryDataSource)) {
         final QueryRunner<T> taskQueryRunner = task.getQueryRunner(query);
 
         if (taskQueryRunner != null) {
@@ -163,7 +171,7 @@ public class ThreadPoolTaskRunner implements TaskRunner, QuerySegmentWalker
             queryRunner = taskQueryRunner;
           } else {
             log.makeAlert("Found too many query runners for datasource")
-               .addData("dataSource", query.getDataSource())
+               .addData("dataSource", queryDataSource)
                .emit();
           }
         }

kafka-eight/pom.xml

@@ -28,7 +28,7 @@
     <parent>
         <groupId>io.druid</groupId>
         <artifactId>druid</artifactId>
-        <version>0.6.63-SNAPSHOT</version>
+        <version>0.6.70-SNAPSHOT</version>
     </parent>
 
     <dependencies>

kafka-seven/pom.xml

@@ -28,7 +28,7 @@
     <parent>
         <groupId>io.druid</groupId>
         <artifactId>druid</artifactId>
-        <version>0.6.63-SNAPSHOT</version>
+        <version>0.6.70-SNAPSHOT</version>
     </parent>
 
     <dependencies>

pom.xml

@@ -23,14 +23,14 @@
     <groupId>io.druid</groupId>
     <artifactId>druid</artifactId>
     <packaging>pom</packaging>
-    <version>0.6.63-SNAPSHOT</version>
+    <version>0.6.70-SNAPSHOT</version>
     <name>druid</name>
     <description>druid</description>
     <scm>
         <connection>scm:git:ssh://git@github.com/metamx/druid.git</connection>
         <developerConnection>scm:git:ssh://git@github.com/metamx/druid.git</developerConnection>
         <url>http://www.github.com/metamx/druid</url>
-        <tag>${project.artifactId}-${project.version}</tag>
+        <tag>druid-0.6.69-SNAPSHOT</tag>
     </scm>
 
     <prerequisites>

processing/pom.xml

@@ -28,7 +28,7 @@
     <parent>
         <groupId>io.druid</groupId>
         <artifactId>druid</artifactId>
-        <version>0.6.63-SNAPSHOT</version>
+        <version>0.6.70-SNAPSHOT</version>
     </parent>
 
     <dependencies>

processing/src/main/java/io/druid/jackson/AggregatorsModule.java

@@ -22,6 +22,7 @@ package io.druid.jackson;
 import com.fasterxml.jackson.annotation.JsonSubTypes;
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
 import com.fasterxml.jackson.databind.module.SimpleModule;
+import com.google.common.hash.Hashing;
 import io.druid.query.aggregation.AggregatorFactory;
 import io.druid.query.aggregation.CountAggregatorFactory;
 import io.druid.query.aggregation.DoubleSumAggregatorFactory;
@@ -31,10 +32,14 @@ import io.druid.query.aggregation.LongSumAggregatorFactory;
 import io.druid.query.aggregation.MaxAggregatorFactory;
 import io.druid.query.aggregation.MinAggregatorFactory;
 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.hyperloglog.HyperUniquesSerde;
 import io.druid.query.aggregation.post.ArithmeticPostAggregator;
 import io.druid.query.aggregation.post.ConstantPostAggregator;
 import io.druid.query.aggregation.post.FieldAccessPostAggregator;
 import io.druid.query.aggregation.post.JavaScriptPostAggregator;
+import io.druid.segment.serde.ComplexMetrics;
 
 /**
  */
@@ -44,28 +49,38 @@ public class AggregatorsModule extends SimpleModule
   {
     super("AggregatorFactories");
 
+    if (ComplexMetrics.getSerdeForType("hyperUnique") == null) {
+      ComplexMetrics.registerSerde("hyperUnique", new HyperUniquesSerde(Hashing.murmur3_128()));
+    }
+
     setMixInAnnotation(AggregatorFactory.class, AggregatorFactoryMixin.class);
     setMixInAnnotation(PostAggregator.class, PostAggregatorMixin.class);
   }
 
-  @JsonTypeInfo(use= JsonTypeInfo.Id.NAME, property="type")
-  @JsonSubTypes(value={
-      @JsonSubTypes.Type(name="count", value=CountAggregatorFactory.class),
-      @JsonSubTypes.Type(name="longSum", value=LongSumAggregatorFactory.class),
-      @JsonSubTypes.Type(name="doubleSum", value=DoubleSumAggregatorFactory.class),
-      @JsonSubTypes.Type(name="max", value=MaxAggregatorFactory.class),
-      @JsonSubTypes.Type(name="min", value=MinAggregatorFactory.class),
-      @JsonSubTypes.Type(name="javascript", value=JavaScriptAggregatorFactory.class),
-      @JsonSubTypes.Type(name="histogram", value=HistogramAggregatorFactory.class)
+  @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property = "type")
+  @JsonSubTypes(value = {
+      @JsonSubTypes.Type(name = "count", value = CountAggregatorFactory.class),
+      @JsonSubTypes.Type(name = "longSum", value = LongSumAggregatorFactory.class),
+      @JsonSubTypes.Type(name = "doubleSum", value = DoubleSumAggregatorFactory.class),
+      @JsonSubTypes.Type(name = "max", value = MaxAggregatorFactory.class),
+      @JsonSubTypes.Type(name = "min", value = MinAggregatorFactory.class),
+      @JsonSubTypes.Type(name = "javascript", value = JavaScriptAggregatorFactory.class),
+      @JsonSubTypes.Type(name = "histogram", value = HistogramAggregatorFactory.class),
+      @JsonSubTypes.Type(name = "hyperUnique", value = HyperUniquesAggregatorFactory.class)
   })
-  public static interface AggregatorFactoryMixin {}
+  public static interface AggregatorFactoryMixin
+  {
+  }
 
   @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, property = "type")
   @JsonSubTypes(value = {
       @JsonSubTypes.Type(name = "arithmetic", value = ArithmeticPostAggregator.class),
       @JsonSubTypes.Type(name = "fieldAccess", value = FieldAccessPostAggregator.class),
       @JsonSubTypes.Type(name = "constant", value = ConstantPostAggregator.class),
-      @JsonSubTypes.Type(name = "javascript", value = JavaScriptPostAggregator.class)
+      @JsonSubTypes.Type(name = "javascript", value = JavaScriptPostAggregator.class),
+      @JsonSubTypes.Type(name = "hyperUniqueCardinality", value = HyperUniqueFinalizingPostAggregator.class)
   })
-  public static interface PostAggregatorMixin {}
+  public static interface PostAggregatorMixin
+  {
+  }
 }

processing/src/main/java/io/druid/query/BaseQuery.java

@@ -36,13 +36,13 @@ import java.util.Map;
 public abstract class BaseQuery<T> implements Query<T>
 {
   public static String QUERYID = "queryId";
-  private final String dataSource;
+  private final DataSource dataSource;
   private final Map<String, String> context;
   private final QuerySegmentSpec querySegmentSpec;
   private volatile Duration duration;
 
   public BaseQuery(
-      String dataSource,
+      DataSource dataSource,
       QuerySegmentSpec querySegmentSpec,
       Map<String, String> context
   )
@@ -50,14 +50,14 @@ public abstract class BaseQuery<T> implements Query<T>
     Preconditions.checkNotNull(dataSource, "dataSource can't be null");
     Preconditions.checkNotNull(querySegmentSpec, "querySegmentSpec can't be null");
 
-    this.dataSource = dataSource.toLowerCase();
+    this.dataSource = dataSource;
     this.context = context;
     this.querySegmentSpec = querySegmentSpec;
   }
 
   @JsonProperty
   @Override
-  public String getDataSource()
+  public DataSource getDataSource()
   {
     return dataSource;
   }
@@ -143,4 +143,31 @@ public abstract class BaseQuery<T> implements Query<T>
   {
     return withOverriddenContext(ImmutableMap.of(QUERYID, id));
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    BaseQuery baseQuery = (BaseQuery) o;
+
+    if (context != null ? !context.equals(baseQuery.context) : baseQuery.context != null) return false;
+    if (dataSource != null ? !dataSource.equals(baseQuery.dataSource) : baseQuery.dataSource != null) return false;
+    if (duration != null ? !duration.equals(baseQuery.duration) : baseQuery.duration != null) return false;
+    if (querySegmentSpec != null ? !querySegmentSpec.equals(baseQuery.querySegmentSpec) : baseQuery.querySegmentSpec != null)
+      return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = dataSource != null ? dataSource.hashCode() : 0;
+    result = 31 * result + (context != null ? context.hashCode() : 0);
+    result = 31 * result + (querySegmentSpec != null ? querySegmentSpec.hashCode() : 0);
+    result = 31 * result + (duration != null ? duration.hashCode() : 0);
+    return result;
+  }
 }

processing/src/main/java/io/druid/query/ChainedExecutionQueryRunner.java

@@ -25,6 +25,7 @@ import com.google.common.base.Throwables;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Ordering;
+import com.metamx.common.ISE;
 import com.metamx.common.guava.BaseSequence;
 import com.metamx.common.guava.MergeIterable;
 import com.metamx.common.guava.Sequence;
@@ -84,11 +85,6 @@ public class ChainedExecutionQueryRunner<T> implements QueryRunner<T>
   {
     final int priority = Integer.parseInt(query.getContextValue("priority", "0"));
 
-    if (Iterables.isEmpty(queryables)) {
-      log.warn("No queryables found.");
-      return Sequences.empty();
-    }
-
     return new BaseSequence<T, Iterator<T>>(
         new BaseSequence.IteratorMaker<T, Iterator<T>>()
         {
@@ -111,6 +107,9 @@ public class ChainedExecutionQueryRunner<T> implements QueryRunner<T>
                               public List<T> call() throws Exception
                               {
                                 try {
+                                  if (input == null) {
+                                    throw new ISE("Input is null?! How is this possible?!");
+                                  }
                                   return Sequences.toList(input.run(query), Lists.<T>newArrayList());
                                 }
                                 catch (Exception e) {

processing/src/main/java/io/druid/query/DataSource.java

@@ -0,0 +1,38 @@
+/*
+ * Druid - a distributed column store.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * This file Copyright (C) 2014 N3TWORK, Inc. and contributed to the Druid project
+ * under the Druid Corporate Contributor License Agreement.
+ */
+
+package io.druid.query;
+
+import com.fasterxml.jackson.annotation.JsonSubTypes;
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+
+@JsonTypeInfo(use = JsonTypeInfo.Id.NAME,
+              include = JsonTypeInfo.As.PROPERTY,
+              property = "type",
+              defaultImpl = LegacyDataSource.class)
+@JsonSubTypes({
+                  @JsonSubTypes.Type(value = TableDataSource.class, name = "table"),
+                  @JsonSubTypes.Type(value = QueryDataSource.class, name = "query")
+              })
+public interface DataSource
+{
+  public String getName();
+}

processing/src/main/java/io/druid/query/Druids.java

@@ -298,7 +298,7 @@ public class Druids
    */
   public static class TimeseriesQueryBuilder
   {
-    private String dataSource;
+    private DataSource dataSource;
     private QuerySegmentSpec querySegmentSpec;
     private DimFilter dimFilter;
     private QueryGranularity granularity;
@@ -308,7 +308,7 @@ public class Druids
 
     private TimeseriesQueryBuilder()
     {
-      dataSource = "";
+      dataSource = null;
       querySegmentSpec = null;
       dimFilter = null;
       granularity = QueryGranularity.ALL;
@@ -354,7 +354,7 @@ public class Druids
           .context(builder.context);
     }
 
-    public String getDataSource()
+    public DataSource getDataSource()
     {
       return dataSource;
     }
@@ -390,6 +390,12 @@ public class Druids
     }
 
     public TimeseriesQueryBuilder dataSource(String ds)
+    {
+      dataSource = new TableDataSource(ds);
+      return this;
+    }
+
+    public TimeseriesQueryBuilder dataSource(DataSource ds)
     {
       dataSource = ds;
       return this;
@@ -492,7 +498,7 @@ public class Druids
    */
   public static class SearchQueryBuilder
   {
-    private String dataSource;
+    private DataSource dataSource;
     private DimFilter dimFilter;
     private QueryGranularity granularity;
     private int limit;
@@ -503,7 +509,7 @@ public class Druids
 
     public SearchQueryBuilder()
     {
-      dataSource = "";
+      dataSource = null;
       dimFilter = null;
       granularity = QueryGranularity.ALL;
       limit = 0;
@@ -531,7 +537,7 @@ public class Druids
     public SearchQueryBuilder copy(SearchQuery query)
     {
       return new SearchQueryBuilder()
-          .dataSource(query.getDataSource())
+          .dataSource(((TableDataSource)query.getDataSource()).getName())
           .intervals(query.getQuerySegmentSpec())
           .filters(query.getDimensionsFilter())
           .granularity(query.getGranularity())
@@ -555,6 +561,12 @@ public class Druids
     }
 
     public SearchQueryBuilder dataSource(String d)
+    {
+      dataSource = new TableDataSource(d);
+      return this;
+    }
+
+    public SearchQueryBuilder dataSource(DataSource d)
     {
       dataSource = d;
       return this;
@@ -676,13 +688,13 @@ public class Druids
    */
   public static class TimeBoundaryQueryBuilder
   {
-    private String dataSource;
+    private DataSource dataSource;
     private QuerySegmentSpec querySegmentSpec;
     private Map<String, String> context;
 
     public TimeBoundaryQueryBuilder()
     {
-      dataSource = "";
+      dataSource = null;
       querySegmentSpec = null;
       context = null;
     }
@@ -704,9 +716,15 @@ public class Druids
           .context(builder.context);
     }
 
-    public TimeBoundaryQueryBuilder dataSource(String d)
+    public TimeBoundaryQueryBuilder dataSource(String ds)
     {
-      dataSource = d;
+      dataSource = new TableDataSource(ds);
+      return this;
+    }
+
+    public TimeBoundaryQueryBuilder dataSource(DataSource ds)
+    {
+      dataSource = ds;
       return this;
     }
 

processing/src/main/java/io/druid/query/LegacyDataSource.java

@@ -0,0 +1,35 @@
+/*
+ * Druid - a distributed column store.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * This file Copyright (C) 2014 N3TWORK, Inc. and contributed to the Druid project
+ * under the Druid Corporate Contributor License Agreement.
+ */
+package io.druid.query;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+
+@JsonTypeName("table")
+public class LegacyDataSource extends TableDataSource
+{
+  @JsonCreator
+  public LegacyDataSource(String name)
+  {
+    super(name);
+  }
+}

processing/src/main/java/io/druid/query/Query.java

@@ -56,7 +56,7 @@ public interface Query<T>
   public static final String SELECT = "select";
   public static final String TOPN = "topN";
 
-  public String getDataSource();
+  public DataSource getDataSource();
 
   public boolean hasFilters();
 

processing/src/main/java/io/druid/query/QueryDataSource.java

@@ -0,0 +1,78 @@
+/*
+ * Druid - a distributed column store.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * This file Copyright (C) 2014 N3TWORK, Inc. and contributed to the Druid project
+ * under the Druid Corporate Contributor License Agreement.
+ */
+
+package io.druid.query;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+
+@JsonTypeName("query")
+public class QueryDataSource implements DataSource
+{
+  @JsonProperty
+  private final Query query;
+
+  @JsonCreator
+  public QueryDataSource(@JsonProperty("query") Query query)
+  {
+    this.query = query;
+  }
+
+  @Override
+  public String getName()
+  {
+    return query.getDataSource().getName();
+  }
+
+  @JsonProperty
+  public Query getQuery()
+  {
+    return query;
+  }
+
+  public String toString() { return query.toString(); }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+
+    QueryDataSource that = (QueryDataSource) o;
+
+    if (!query.equals(that.query)) {
+      return false;
+    }
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    return query.hashCode();
+  }
+}

processing/src/main/java/io/druid/query/SubqueryQueryRunner.java

@@ -0,0 +1,48 @@
+/*
+ * Druid - a distributed column store.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * This file Copyright (C) 2014 N3TWORK, Inc. and contributed to the Druid project
+ * under the Druid Corporate Contributor License Agreement.
+ */
+
+package io.druid.query;
+
+import com.metamx.common.guava.Sequence;
+
+/**
+ * If there's a subquery, run it instead of the outer query
+ */
+public class SubqueryQueryRunner<T> implements QueryRunner<T>
+{
+  private final QueryRunner<T> baseRunner;
+
+  public SubqueryQueryRunner(QueryRunner<T> baseRunner)
+  {
+    this.baseRunner = baseRunner;
+  }
+
+  @Override
+  public Sequence<T> run(final Query<T> query)
+  {
+    DataSource dataSource = query.getDataSource();
+    if (dataSource instanceof QueryDataSource) {
+      return run((Query<T>) ((QueryDataSource) dataSource).getQuery());
+    } else {
+      return baseRunner.run(query);
+    }
+  }
+}

processing/src/main/java/io/druid/query/TableDataSource.java

@@ -0,0 +1,72 @@
+/*
+ * Druid - a distributed column store.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * This file Copyright (C) 2014 N3TWORK, Inc. and contributed to the Druid project
+ * under the Druid Corporate Contributor License Agreement.
+ */
+package io.druid.query;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonTypeName;
+
+@JsonTypeName("table")
+public class TableDataSource implements DataSource
+{
+  @JsonProperty
+  private final String name;
+
+  @JsonCreator
+  public TableDataSource(@JsonProperty("name") String name)
+  {
+    this.name = (name == null ? null : name.toLowerCase());
+  }
+
+  @JsonProperty
+  @Override
+  public String getName()
+  {
+    return name;
+  }
+
+  public String toString() { return name; }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) {
+      return true;
+    }
+    if (!(o instanceof TableDataSource)) {
+      return false;
+    }
+
+    TableDataSource that = (TableDataSource) o;
+
+    if (!name.equals(that.name)) {
+      return false;
+    }
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    return name.hashCode();
+  }
+}

processing/src/main/java/io/druid/query/aggregation/CountAggregatorFactory.java

@@ -132,4 +132,23 @@ public class CountAggregatorFactory implements AggregatorFactory
            "name='" + name + '\'' +
            '}';
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    CountAggregatorFactory that = (CountAggregatorFactory) o;
+
+    if (name != null ? !name.equals(that.name) : that.name != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    return name != null ? name.hashCode() : 0;
+  }
 }

processing/src/main/java/io/druid/query/aggregation/DoubleSumAggregatorFactory.java

@@ -150,4 +150,26 @@ public class DoubleSumAggregatorFactory implements AggregatorFactory
            ", name='" + name + '\'' +
            '}';
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    DoubleSumAggregatorFactory that = (DoubleSumAggregatorFactory) o;
+
+    if (fieldName != null ? !fieldName.equals(that.fieldName) : that.fieldName != null) return false;
+    if (name != null ? !name.equals(that.name) : that.name != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = fieldName != null ? fieldName.hashCode() : 0;
+    result = 31 * result + (name != null ? name.hashCode() : 0);
+    return result;
+  }
 }

processing/src/main/java/io/druid/query/aggregation/HistogramAggregatorFactory.java

@@ -179,4 +179,30 @@ public class HistogramAggregatorFactory implements AggregatorFactory
            ", breaks=" + Arrays.toString(breaks) +
            '}';
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    HistogramAggregatorFactory that = (HistogramAggregatorFactory) o;
+
+    if (!Arrays.equals(breaks, that.breaks)) return false;
+    if (breaksList != null ? !breaksList.equals(that.breaksList) : that.breaksList != null) return false;
+    if (fieldName != null ? !fieldName.equals(that.fieldName) : that.fieldName != null) return false;
+    if (name != null ? !name.equals(that.name) : that.name != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = name != null ? name.hashCode() : 0;
+    result = 31 * result + (fieldName != null ? fieldName.hashCode() : 0);
+    result = 31 * result + (breaksList != null ? breaksList.hashCode() : 0);
+    result = 31 * result + (breaks != null ? Arrays.hashCode(breaks) : 0);
+    return result;
+  }
 }

processing/src/main/java/io/druid/query/aggregation/JavaScriptAggregatorFactory.java

@@ -317,4 +317,35 @@ public class JavaScriptAggregatorFactory implements AggregatorFactory
       }
     };
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    JavaScriptAggregatorFactory that = (JavaScriptAggregatorFactory) o;
+
+    if (compiledScript != null ? !compiledScript.equals(that.compiledScript) : that.compiledScript != null)
+      return false;
+    if (fieldNames != null ? !fieldNames.equals(that.fieldNames) : that.fieldNames != null) return false;
+    if (fnAggregate != null ? !fnAggregate.equals(that.fnAggregate) : that.fnAggregate != null) return false;
+    if (fnCombine != null ? !fnCombine.equals(that.fnCombine) : that.fnCombine != null) return false;
+    if (fnReset != null ? !fnReset.equals(that.fnReset) : that.fnReset != null) return false;
+    if (name != null ? !name.equals(that.name) : that.name != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = name != null ? name.hashCode() : 0;
+    result = 31 * result + (fieldNames != null ? fieldNames.hashCode() : 0);
+    result = 31 * result + (fnAggregate != null ? fnAggregate.hashCode() : 0);
+    result = 31 * result + (fnReset != null ? fnReset.hashCode() : 0);
+    result = 31 * result + (fnCombine != null ? fnCombine.hashCode() : 0);
+    result = 31 * result + (compiledScript != null ? compiledScript.hashCode() : 0);
+    return result;
+  }
 }

processing/src/main/java/io/druid/query/aggregation/LongSumAggregatorFactory.java

@@ -150,4 +150,26 @@ public class LongSumAggregatorFactory implements AggregatorFactory
            ", name='" + name + '\'' +
            '}';
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    LongSumAggregatorFactory that = (LongSumAggregatorFactory) o;
+
+    if (fieldName != null ? !fieldName.equals(that.fieldName) : that.fieldName != null) return false;
+    if (name != null ? !name.equals(that.name) : that.name != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = fieldName != null ? fieldName.hashCode() : 0;
+    result = 31 * result + (name != null ? name.hashCode() : 0);
+    return result;
+  }
 }

processing/src/main/java/io/druid/query/aggregation/MaxAggregatorFactory.java

@@ -150,4 +150,26 @@ public class MaxAggregatorFactory implements AggregatorFactory
            ", name='" + name + '\'' +
            '}';
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    MaxAggregatorFactory that = (MaxAggregatorFactory) o;
+
+    if (fieldName != null ? !fieldName.equals(that.fieldName) : that.fieldName != null) return false;
+    if (name != null ? !name.equals(that.name) : that.name != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = fieldName != null ? fieldName.hashCode() : 0;
+    result = 31 * result + (name != null ? name.hashCode() : 0);
+    return result;
+  }
 }

processing/src/main/java/io/druid/query/aggregation/MinAggregatorFactory.java

@@ -150,4 +150,26 @@ public class MinAggregatorFactory implements AggregatorFactory
            ", name='" + name + '\'' +
            '}';
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    MinAggregatorFactory that = (MinAggregatorFactory) o;
+
+    if (fieldName != null ? !fieldName.equals(that.fieldName) : that.fieldName != null) return false;
+    if (name != null ? !name.equals(that.name) : that.name != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = fieldName != null ? fieldName.hashCode() : 0;
+    result = 31 * result + (name != null ? name.hashCode() : 0);
+    return result;
+  }
 }

processing/src/main/java/io/druid/query/aggregation/ToLowerCaseAggregatorFactory.java

@@ -112,4 +112,24 @@ public class ToLowerCaseAggregatorFactory implements AggregatorFactory
   {
     return baseAggregatorFactory.getAggregatorStartValue();
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    ToLowerCaseAggregatorFactory that = (ToLowerCaseAggregatorFactory) o;
+
+    if (baseAggregatorFactory != null ? !baseAggregatorFactory.equals(that.baseAggregatorFactory) : that.baseAggregatorFactory != null)
+      return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    return baseAggregatorFactory != null ? baseAggregatorFactory.hashCode() : 0;
+  }
 }

processing/src/main/java/io/druid/query/aggregation/hyperloglog/ByteBitLookup.java

@@ -0,0 +1,288 @@
+/*
+ * Druid - a distributed column store.
+ * Copyright (C) 2012, 2013  Metamarkets Group Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+package io.druid.query.aggregation.hyperloglog;
+
+/**
+ */
+public class ByteBitLookup
+{
+  public static final byte[] lookup;
+
+  static {
+    lookup = new byte[256];
+
+    lookup[0] = 0;
+    lookup[1] = 1;
+    lookup[2] = 2;
+    lookup[3] = 1;
+    lookup[4] = 3;
+    lookup[5] = 1;
+    lookup[6] = 2;
+    lookup[7] = 1;
+    lookup[8] = 4;
+    lookup[9] = 1;
+    lookup[10] = 2;
+    lookup[11] = 1;
+    lookup[12] = 3;
+    lookup[13] = 1;
+    lookup[14] = 2;
+    lookup[15] = 1;
+    lookup[16] = 5;
+    lookup[17] = 1;
+    lookup[18] = 2;
+    lookup[19] = 1;
+    lookup[20] = 3;
+    lookup[21] = 1;
+    lookup[22] = 2;
+    lookup[23] = 1;
+    lookup[24] = 4;
+    lookup[25] = 1;
+    lookup[26] = 2;
+    lookup[27] = 1;
+    lookup[28] = 3;
+    lookup[29] = 1;
+    lookup[30] = 2;
+    lookup[31] = 1;
+    lookup[32] = 6;
+    lookup[33] = 1;
+    lookup[34] = 2;
+    lookup[35] = 1;
+    lookup[36] = 3;
+    lookup[37] = 1;
+    lookup[38] = 2;
+    lookup[39] = 1;
+    lookup[40] = 4;
+    lookup[41] = 1;
+    lookup[42] = 2;
+    lookup[43] = 1;
+    lookup[44] = 3;
+    lookup[45] = 1;
+    lookup[46] = 2;
+    lookup[47] = 1;
+    lookup[48] = 5;
+    lookup[49] = 1;
+    lookup[50] = 2;
+    lookup[51] = 1;
+    lookup[52] = 3;
+    lookup[53] = 1;
+    lookup[54] = 2;
+    lookup[55] = 1;
+    lookup[56] = 4;
+    lookup[57] = 1;
+    lookup[58] = 2;
+    lookup[59] = 1;
+    lookup[60] = 3;
+    lookup[61] = 1;
+    lookup[62] = 2;
+    lookup[63] = 1;
+    lookup[64] = 7;
+    lookup[65] = 1;
+    lookup[66] = 2;
+    lookup[67] = 1;
+    lookup[68] = 3;
+    lookup[69] = 1;
+    lookup[70] = 2;
+    lookup[71] = 1;
+    lookup[72] = 4;
+    lookup[73] = 1;
+    lookup[74] = 2;
+    lookup[75] = 1;
+    lookup[76] = 3;
+    lookup[77] = 1;
+    lookup[78] = 2;
+    lookup[79] = 1;
+    lookup[80] = 5;
+    lookup[81] = 1;
+    lookup[82] = 2;
+    lookup[83] = 1;
+    lookup[84] = 3;
+    lookup[85] = 1;
+    lookup[86] = 2;
+    lookup[87] = 1;
+    lookup[88] = 4;
+    lookup[89] = 1;
+    lookup[90] = 2;
+    lookup[91] = 1;
+    lookup[92] = 3;
+    lookup[93] = 1;
+    lookup[94] = 2;
+    lookup[95] = 1;
+    lookup[96] = 6;
+    lookup[97] = 1;
+    lookup[98] = 2;
+    lookup[99] = 1;
+    lookup[100] = 3;
+    lookup[101] = 1;
+    lookup[102] = 2;
+    lookup[103] = 1;
+    lookup[104] = 4;
+    lookup[105] = 1;
+    lookup[106] = 2;
+    lookup[107] = 1;
+    lookup[108] = 3;
+    lookup[109] = 1;
+    lookup[110] = 2;
+    lookup[111] = 1;
+    lookup[112] = 5;
+    lookup[113] = 1;
+    lookup[114] = 2;
+    lookup[115] = 1;
+    lookup[116] = 3;
+    lookup[117] = 1;
+    lookup[118] = 2;
+    lookup[119] = 1;
+    lookup[120] = 4;
+    lookup[121] = 1;
+    lookup[122] = 2;
+    lookup[123] = 1;
+    lookup[124] = 3;
+    lookup[125] = 1;
+    lookup[126] = 2;
+    lookup[127] = 1;
+    lookup[128] = 8;
+    lookup[129] = 1;
+    lookup[130] = 2;
+    lookup[131] = 1;
+    lookup[132] = 3;
+    lookup[133] = 1;
+    lookup[134] = 2;
+    lookup[135] = 1;
+    lookup[136] = 4;
+    lookup[137] = 1;
+    lookup[138] = 2;
+    lookup[139] = 1;
+    lookup[140] = 3;
+    lookup[141] = 1;
+    lookup[142] = 2;
+    lookup[143] = 1;
+    lookup[144] = 5;
+    lookup[145] = 1;
+    lookup[146] = 2;
+    lookup[147] = 1;
+    lookup[148] = 3;
+    lookup[149] = 1;
+    lookup[150] = 2;
+    lookup[151] = 1;
+    lookup[152] = 4;
+    lookup[153] = 1;
+    lookup[154] = 2;
+    lookup[155] = 1;
+    lookup[156] = 3;
+    lookup[157] = 1;
+    lookup[158] = 2;
+    lookup[159] = 1;
+    lookup[160] = 6;
+    lookup[161] = 1;
+    lookup[162] = 2;
+    lookup[163] = 1;
+    lookup[164] = 3;
+    lookup[165] = 1;
+    lookup[166] = 2;
+    lookup[167] = 1;
+    lookup[168] = 4;
+    lookup[169] = 1;
+    lookup[170] = 2;
+    lookup[171] = 1;
+    lookup[172] = 3;
+    lookup[173] = 1;
+    lookup[174] = 2;
+    lookup[175] = 1;
+    lookup[176] = 5;
+    lookup[177] = 1;
+    lookup[178] = 2;
+    lookup[179] = 1;
+    lookup[180] = 3;
+    lookup[181] = 1;
+    lookup[182] = 2;
+    lookup[183] = 1;
+    lookup[184] = 4;
+    lookup[185] = 1;
+    lookup[186] = 2;
+    lookup[187] = 1;
+    lookup[188] = 3;
+    lookup[189] = 1;
+    lookup[190] = 2;
+    lookup[191] = 1;
+    lookup[192] = 7;
+    lookup[193] = 1;
+    lookup[194] = 2;
+    lookup[195] = 1;
+    lookup[196] = 3;
+    lookup[197] = 1;
+    lookup[198] = 2;
+    lookup[199] = 1;
+    lookup[200] = 4;
+    lookup[201] = 1;
+    lookup[202] = 2;
+    lookup[203] = 1;
+    lookup[204] = 3;
+    lookup[205] = 1;
+    lookup[206] = 2;
+    lookup[207] = 1;
+    lookup[208] = 5;
+    lookup[209] = 1;
+    lookup[210] = 2;
+    lookup[211] = 1;
+    lookup[212] = 3;
+    lookup[213] = 1;
+    lookup[214] = 2;
+    lookup[215] = 1;
+    lookup[216] = 4;
+    lookup[217] = 1;
+    lookup[218] = 2;
+    lookup[219] = 1;
+    lookup[220] = 3;
+    lookup[221] = 1;
+    lookup[222] = 2;
+    lookup[223] = 1;
+    lookup[224] = 6;
+    lookup[225] = 1;
+    lookup[226] = 2;
+    lookup[227] = 1;
+    lookup[228] = 3;
+    lookup[229] = 1;
+    lookup[230] = 2;
+    lookup[231] = 1;
+    lookup[232] = 4;
+    lookup[233] = 1;
+    lookup[234] = 2;
+    lookup[235] = 1;
+    lookup[236] = 3;
+    lookup[237] = 1;
+    lookup[238] = 2;
+    lookup[239] = 1;
+    lookup[240] = 5;
+    lookup[241] = 1;
+    lookup[242] = 2;
+    lookup[243] = 1;
+    lookup[244] = 3;
+    lookup[245] = 1;
+    lookup[246] = 2;
+    lookup[247] = 1;
+    lookup[248] = 4;
+    lookup[249] = 1;
+    lookup[250] = 2;
+    lookup[251] = 1;
+    lookup[252] = 3;
+    lookup[253] = 1;
+    lookup[254] = 2;
+    lookup[255] = 1;
+  }
+}

processing/src/main/java/io/druid/query/aggregation/hyperloglog/HLLCV0.java

@@ -0,0 +1,152 @@
+/*
+ * Druid - a distributed column store.
+ * Copyright (C) 2012, 2013  Metamarkets Group Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+package io.druid.query.aggregation.hyperloglog;
+
+import java.nio.ByteBuffer;
+
+/**
+ */
+@Deprecated
+public class HLLCV0 extends HyperLogLogCollector
+{
+  /**
+   * Header:
+   * Byte 0: registerOffset
+   * Byte 1-2: numNonZeroRegisters
+   */
+  public static final int NUM_NON_ZERO_REGISTERS_BYTE = 1;
+  public static final int HEADER_NUM_BYTES = 3;
+  public static final int NUM_BYTES_FOR_DENSE_STORAGE = NUM_BYTES_FOR_BUCKETS + HEADER_NUM_BYTES;
+
+  private static final ByteBuffer defaultStorageBuffer = ByteBuffer.wrap(new byte[]{0, 0, 0}).asReadOnlyBuffer();
+
+  public HLLCV0()
+  {
+    super(defaultStorageBuffer);
+  }
+
+  public HLLCV0(ByteBuffer buffer)
+  {
+    super(buffer);
+  }
+
+  @Override
+  public byte getVersion()
+  {
+    return 0;
+  }
+
+  @Override
+  public void setVersion(ByteBuffer buffer)
+  {
+  }
+
+  @Override
+  public byte getRegisterOffset()
+  {
+    return getStorageBuffer().get(getInitPosition());
+  }
+
+  @Override
+  public void setRegisterOffset(byte registerOffset)
+  {
+    getStorageBuffer().put(getInitPosition(), registerOffset);
+  }
+
+  @Override
+  public void setRegisterOffset(ByteBuffer buffer, byte registerOffset)
+  {
+    buffer.put(buffer.position(), registerOffset);
+  }
+
+  @Override
+  public short getNumNonZeroRegisters()
+  {
+    return getStorageBuffer().getShort(getInitPosition() + NUM_NON_ZERO_REGISTERS_BYTE);
+  }
+
+  @Override
+  public void setNumNonZeroRegisters(short numNonZeroRegisters)
+  {
+    getStorageBuffer().putShort(getInitPosition() + NUM_NON_ZERO_REGISTERS_BYTE, numNonZeroRegisters);
+  }
+
+  @Override
+  public void setNumNonZeroRegisters(ByteBuffer buffer, short numNonZeroRegisters)
+  {
+    buffer.putShort(buffer.position() + NUM_NON_ZERO_REGISTERS_BYTE, numNonZeroRegisters);
+  }
+
+  @Override
+  public byte getMaxOverflowValue()
+  {
+    return 0;
+  }
+
+  @Override
+  public void setMaxOverflowValue(byte value)
+  {
+  }
+
+  @Override
+  public void setMaxOverflowValue(ByteBuffer buffer, byte value)
+  {
+  }
+
+  @Override
+  public short getMaxOverflowRegister()
+  {
+    return 0;
+  }
+
+  @Override
+  public void setMaxOverflowRegister(short register)
+  {
+  }
+
+  @Override
+  public void setMaxOverflowRegister(ByteBuffer buffer, short register)
+  {
+  }
+
+  @Override
+  public int getNumHeaderBytes()
+  {
+    return HEADER_NUM_BYTES;
+  }
+
+  @Override
+  public int getNumBytesForDenseStorage()
+  {
+    return NUM_BYTES_FOR_DENSE_STORAGE;
+  }
+
+  @Override
+  public int getPayloadBytePosition()
+  {
+    return getInitPosition() + HEADER_NUM_BYTES;
+  }
+
+  @Override
+  public int getPayloadBytePosition(ByteBuffer buffer)
+  {
+    return buffer.position() + HEADER_NUM_BYTES;
+  }
+}

processing/src/main/java/io/druid/query/aggregation/hyperloglog/HLLCV1.java

@@ -0,0 +1,164 @@
+/*
+ * Druid - a distributed column store.
+ * Copyright (C) 2012, 2013  Metamarkets Group Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+package io.druid.query.aggregation.hyperloglog;
+
+import java.nio.ByteBuffer;
+
+/**
+ */
+public class HLLCV1 extends HyperLogLogCollector
+{
+  /**
+   * Header:
+   * Byte 0: version
+   * Byte 1: registerOffset
+   * Byte 2-3: numNonZeroRegisters
+   * Byte 4: maxOverflowValue
+   * Byte 5-6: maxOverflowRegister
+   */
+  public static final byte VERSION = 0x1;
+  public static final int REGISTER_OFFSET_BYTE = 1;
+  public static final int NUM_NON_ZERO_REGISTERS_BYTE = 2;
+  public static final int MAX_OVERFLOW_VALUE_BYTE = 4;
+  public static final int MAX_OVERFLOW_REGISTER_BYTE = 5;
+  public static final int HEADER_NUM_BYTES = 7;
+  public static final int NUM_BYTES_FOR_DENSE_STORAGE = NUM_BYTES_FOR_BUCKETS + HEADER_NUM_BYTES;
+
+  private static final ByteBuffer defaultStorageBuffer = ByteBuffer.wrap(new byte[]{VERSION, 0, 0, 0, 0, 0, 0})
+                                                                   .asReadOnlyBuffer();
+
+  public HLLCV1()
+  {
+    super(defaultStorageBuffer);
+  }
+
+  public HLLCV1(ByteBuffer buffer)
+  {
+    super(buffer);
+  }
+
+  @Override
+  public byte getVersion()
+  {
+    return VERSION;
+  }
+
+  @Override
+  public void setVersion(ByteBuffer buffer)
+  {
+    buffer.put(buffer.position(), VERSION);
+  }
+
+  @Override
+  public byte getRegisterOffset()
+  {
+    return getStorageBuffer().get(getInitPosition() + REGISTER_OFFSET_BYTE);
+  }
+
+  @Override
+  public void setRegisterOffset(byte registerOffset)
+  {
+    getStorageBuffer().put(getInitPosition() + REGISTER_OFFSET_BYTE, registerOffset);
+  }
+
+  @Override
+  public void setRegisterOffset(ByteBuffer buffer, byte registerOffset)
+  {
+    buffer.put(buffer.position() + REGISTER_OFFSET_BYTE, registerOffset);
+  }
+
+  @Override
+  public short getNumNonZeroRegisters()
+  {
+    return getStorageBuffer().getShort(getInitPosition() + NUM_NON_ZERO_REGISTERS_BYTE);
+  }
+
+  @Override
+  public void setNumNonZeroRegisters(short numNonZeroRegisters)
+  {
+    getStorageBuffer().putShort(getInitPosition() + NUM_NON_ZERO_REGISTERS_BYTE, numNonZeroRegisters);
+  }
+
+  @Override
+  public void setNumNonZeroRegisters(ByteBuffer buffer, short numNonZeroRegisters)
+  {
+    buffer.putShort(buffer.position() + NUM_NON_ZERO_REGISTERS_BYTE, numNonZeroRegisters);
+  }
+
+  @Override
+  public byte getMaxOverflowValue()
+  {
+    return getStorageBuffer().get(getInitPosition() + MAX_OVERFLOW_VALUE_BYTE);
+  }
+
+  @Override
+  public void setMaxOverflowValue(byte value)
+  {
+    getStorageBuffer().put(getInitPosition() + MAX_OVERFLOW_VALUE_BYTE, value);
+  }
+
+  @Override
+  public void setMaxOverflowValue(ByteBuffer buffer, byte value)
+  {
+    buffer.put(buffer.position() + MAX_OVERFLOW_VALUE_BYTE, value);
+  }
+
+  @Override
+  public short getMaxOverflowRegister()
+  {
+    return getStorageBuffer().getShort(getInitPosition() + MAX_OVERFLOW_REGISTER_BYTE);
+  }
+
+  @Override
+  public void setMaxOverflowRegister(short register)
+  {
+    getStorageBuffer().putShort(getInitPosition() + MAX_OVERFLOW_REGISTER_BYTE, register);
+  }
+
+  @Override
+  public void setMaxOverflowRegister(ByteBuffer buffer, short register)
+  {
+    buffer.putShort(buffer.position() + MAX_OVERFLOW_REGISTER_BYTE, register);
+  }
+
+  @Override
+  public int getNumHeaderBytes()
+  {
+    return HEADER_NUM_BYTES;
+  }
+
+  @Override
+  public int getNumBytesForDenseStorage()
+  {
+    return NUM_BYTES_FOR_DENSE_STORAGE;
+  }
+
+  @Override
+  public int getPayloadBytePosition()
+  {
+    return getInitPosition() + HEADER_NUM_BYTES;
+  }
+
+  @Override
+  public int getPayloadBytePosition(ByteBuffer buffer)
+  {
+    return buffer.position() + HEADER_NUM_BYTES;
+  }
+}

processing/src/main/java/io/druid/query/aggregation/hyperloglog/HyperLogLogCollector.java

@@ -0,0 +1,673 @@
+/*
+ * Druid - a distributed column store.
+ * Copyright (C) 2012, 2013  Metamarkets Group Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+package io.druid.query.aggregation.hyperloglog;
+
+import com.fasterxml.jackson.annotation.JsonValue;
+import com.google.common.primitives.UnsignedBytes;
+import com.metamx.common.IAE;
+import com.metamx.common.ISE;
+import com.metamx.common.logger.Logger;
+
+import java.nio.ByteBuffer;
+
+/**
+ * Implements the HyperLogLog cardinality estimator described in:
+ * <p/>
+ * http://algo.inria.fr/flajolet/Publications/FlFuGaMe07.pdf
+ * <p/>
+ * Run this code to see a simple indication of expected errors based on different m values:
+ * <p/>
+ * for (int i = 1; i < 20; ++i) {
+ * System.out.printf("i[%,d], val[%,d] => error[%f%%]%n", i, 2 << i, 104 / Math.sqrt(2 << i));
+ * }
+ * <p/>
+ * This class is *not* multi-threaded.  It can be passed among threads, but it is written with the assumption that
+ * only one thread is ever calling methods on it.
+ * <p/>
+ * If you have multiple threads calling methods on this concurrently, I hope you manage to get correct behavior
+ */
+public abstract class HyperLogLogCollector implements Comparable<HyperLogLogCollector>
+{
+  public static final int DENSE_THRESHOLD = 128;
+  public static final int BITS_FOR_BUCKETS = 11;
+  public static final int NUM_BUCKETS = 1 << BITS_FOR_BUCKETS;
+  public static final int NUM_BYTES_FOR_BUCKETS = NUM_BUCKETS / 2;
+
+  private static final double TWO_TO_THE_SIXTY_FOUR = Math.pow(2, 64);
+  private static final double ALPHA = 0.7213 / (1 + 1.079 / NUM_BUCKETS);
+
+  public static final double LOW_CORRECTION_THRESHOLD = (5 * NUM_BUCKETS) / 2.0d;
+  public static final double HIGH_CORRECTION_THRESHOLD = TWO_TO_THE_SIXTY_FOUR / 30.0d;
+  public static final double CORRECTION_PARAMETER = ALPHA * NUM_BUCKETS * NUM_BUCKETS;
+
+  private static final Logger log = new Logger(HyperLogLogCollector.class);
+  private static final int bucketMask = 0x7ff;
+  private static final int minBytesRequired = 10;
+  private static final int bitsPerBucket = 4;
+  private static final int range = (int) Math.pow(2, bitsPerBucket) - 1;
+
+  private final static double[][] minNumRegisterLookup = new double[64][256];
+
+  static {
+    for (int registerOffset = 0; registerOffset < 64; ++registerOffset) {
+      for (int register = 0; register < 256; ++register) {
+        final int upper = ((register & 0xf0) >> 4) + registerOffset;
+        final int lower = (register & 0x0f) + registerOffset;
+        minNumRegisterLookup[registerOffset][register] = 1.0d / Math.pow(2, upper) + 1.0d / Math.pow(2, lower);
+      }
+    }
+  }
+
+  // we have to keep track of the number of zeroes in each of the two halves of the byte register (0, 1, or 2)
+  private final static int[] numZeroLookup = new int[256];
+
+  static {
+    for (int i = 0; i < numZeroLookup.length; ++i) {
+      numZeroLookup[i] = (((i & 0xf0) == 0) ? 1 : 0) + (((i & 0x0f) == 0) ? 1 : 0);
+    }
+  }
+
+  // Methods to build the latest HLLC
+  public static HyperLogLogCollector makeLatestCollector()
+  {
+    return new HLLCV1();
+  }
+
+  public static HyperLogLogCollector makeCollector(ByteBuffer buffer)
+  {
+    int remaining = buffer.remaining();
+    return (remaining % 3 == 0 || remaining == 1027) ? new HLLCV0(buffer) : new HLLCV1(buffer);
+  }
+
+  public static int getLatestNumBytesForDenseStorage()
+  {
+    return HLLCV1.NUM_BYTES_FOR_DENSE_STORAGE;
+  }
+
+  public static byte[] makeEmptyVersionedByteArray()
+  {
+    byte[] arr = new byte[getLatestNumBytesForDenseStorage()];
+    arr[0] = HLLCV1.VERSION;
+    return arr;
+  }
+
+  public static double applyCorrection(double e, int zeroCount)
+  {
+    e = CORRECTION_PARAMETER / e;
+
+    if (e <= LOW_CORRECTION_THRESHOLD) {
+      return zeroCount == 0 ? e : NUM_BUCKETS * Math.log(NUM_BUCKETS / (double) zeroCount);
+    }
+
+    if (e > HIGH_CORRECTION_THRESHOLD) {
+      final double ratio = e / TWO_TO_THE_SIXTY_FOUR;
+      if (ratio >= 1) {
+        // handle very unlikely case that value is > 2^64
+        return Double.MAX_VALUE;
+      } else {
+        return -TWO_TO_THE_SIXTY_FOUR * Math.log(1 - ratio);
+      }
+    }
+
+    return e;
+  }
+
+  private static double estimateSparse(
+      final ByteBuffer buf,
+      final byte minNum,
+      final byte overflowValue,
+      final short overflowPosition,
+      final boolean isUpperNibble
+  )
+  {
+    final ByteBuffer copy = buf.asReadOnlyBuffer();
+    double e = 0.0d;
+    int zeroCount = NUM_BUCKETS - 2 * (buf.remaining() / 3);
+    while (copy.hasRemaining()) {
+      short position = copy.getShort();
+      final int register = (int) copy.get() & 0xff;
+      if (overflowValue != 0 && position == overflowPosition) {
+        int upperNibble = ((register & 0xf0) >>> bitsPerBucket) + minNum;
+        int lowerNibble = (register & 0x0f) + minNum;
+        if (isUpperNibble) {
+          upperNibble = Math.max(upperNibble, overflowValue);
+        } else {
+          lowerNibble = Math.max(lowerNibble, overflowValue);
+        }
+        e += 1.0d / Math.pow(2, upperNibble) + 1.0d / Math.pow(2, lowerNibble);
+        zeroCount += (((upperNibble & 0xf0) == 0) ? 1 : 0) + (((lowerNibble & 0x0f) == 0) ? 1 : 0);
+      } else {
+        e += minNumRegisterLookup[minNum][register];
+        zeroCount += numZeroLookup[register];
+      }
+    }
+
+    e += zeroCount;
+    return applyCorrection(e, zeroCount);
+  }
+
+  private static double estimateDense(
+      final ByteBuffer buf,
+      final byte minNum,
+      final byte overflowValue,
+      final short overflowPosition,
+      final boolean isUpperNibble
+  )
+  {
+    final ByteBuffer copy = buf.asReadOnlyBuffer();
+    double e = 0.0d;
+    int zeroCount = 0;
+    int position = 0;
+    while (copy.hasRemaining()) {
+      final int register = (int) copy.get() & 0xff;
+      if (overflowValue != 0 && position == overflowPosition) {
+        int upperNibble = ((register & 0xf0) >>> bitsPerBucket) + minNum;
+        int lowerNibble = (register & 0x0f) + minNum;
+        if (isUpperNibble) {
+          upperNibble = Math.max(upperNibble, overflowValue);
+        } else {
+          lowerNibble = Math.max(lowerNibble, overflowValue);
+        }
+        e += 1.0d / Math.pow(2, upperNibble) + 1.0d / Math.pow(2, lowerNibble);
+        zeroCount += (((upperNibble & 0xf0) == 0) ? 1 : 0) + (((lowerNibble & 0x0f) == 0) ? 1 : 0);
+      } else {
+        e += minNumRegisterLookup[minNum][register];
+        zeroCount += numZeroLookup[register];
+      }
+      position++;
+    }
+
+    return applyCorrection(e, zeroCount);
+  }
+
+  private static boolean isSparse(ByteBuffer buffer)
+  {
+    return buffer.remaining() != NUM_BYTES_FOR_BUCKETS;
+  }
+
+  private volatile ByteBuffer storageBuffer;
+  private volatile int initPosition;
+  private volatile Double estimatedCardinality;
+
+  public HyperLogLogCollector(ByteBuffer byteBuffer)
+  {
+    storageBuffer = byteBuffer.duplicate();
+    initPosition = byteBuffer.position();
+    estimatedCardinality = null;
+  }
+
+  public abstract byte getVersion();
+
+  public abstract void setVersion(ByteBuffer buffer);
+
+  public abstract byte getRegisterOffset();
+
+  public abstract void setRegisterOffset(byte registerOffset);
+
+  public abstract void setRegisterOffset(ByteBuffer buffer, byte registerOffset);
+
+  public abstract short getNumNonZeroRegisters();
+
+  public abstract void setNumNonZeroRegisters(short numNonZeroRegisters);
+
+  public abstract void setNumNonZeroRegisters(ByteBuffer buffer, short numNonZeroRegisters);
+
+  public abstract byte getMaxOverflowValue();
+
+  public abstract void setMaxOverflowValue(byte value);
+
+  public abstract void setMaxOverflowValue(ByteBuffer buffer, byte value);
+
+  public abstract short getMaxOverflowRegister();
+
+  public abstract void setMaxOverflowRegister(short register);
+
+  public abstract void setMaxOverflowRegister(ByteBuffer buffer, short register);
+
+  public abstract int getNumHeaderBytes();
+
+  public abstract int getNumBytesForDenseStorage();
+
+  public abstract int getPayloadBytePosition();
+
+  public abstract int getPayloadBytePosition(ByteBuffer buffer);
+
+  protected int getInitPosition()
+  {
+    return initPosition;
+  }
+
+  protected ByteBuffer getStorageBuffer()
+  {
+    return storageBuffer;
+  }
+
+  public void add(byte[] hashedValue)
+  {
+    if (hashedValue.length < minBytesRequired) {
+      throw new IAE("Insufficient bytes, need[%d] got [%d]", minBytesRequired, hashedValue.length);
+    }
+
+    estimatedCardinality = null;
+
+    final ByteBuffer buffer = ByteBuffer.wrap(hashedValue);
+
+    short bucket = (short) (buffer.getShort(hashedValue.length - 2) & bucketMask);
+
+    byte positionOf1 = 0;
+
+    for (int i = 0; i < 8; ++i) {
+      byte lookupVal = ByteBitLookup.lookup[UnsignedBytes.toInt(hashedValue[i])];
+      switch (lookupVal) {
+        case 0:
+          positionOf1 += 8;
+          continue;
+        default:
+          positionOf1 += lookupVal;
+          i = 8;
+          break;
+      }
+    }
+
+    add(bucket, positionOf1);
+  }
+
+  public void add(short bucket, byte positionOf1)
+  {
+    if (storageBuffer.isReadOnly()) {
+      convertToMutableByteBuffer();
+    }
+
+    byte registerOffset = getRegisterOffset();
+
+    // discard everything outside of the range we care about
+    if (positionOf1 <= registerOffset) {
+      return;
+    } else if (positionOf1 > (registerOffset + range)) {
+      byte currMax = getMaxOverflowValue();
+      if (positionOf1 > currMax) {
+        setMaxOverflowValue(positionOf1);
+        setMaxOverflowRegister(bucket);
+      }
+      return;
+    }
+
+    // whatever value we add must be stored in 4 bits
+    short numNonZeroRegisters = addNibbleRegister(bucket, (byte) ((0xff & positionOf1) - registerOffset));
+    setNumNonZeroRegisters(numNonZeroRegisters);
+    if (numNonZeroRegisters == NUM_BUCKETS) {
+      setRegisterOffset(++registerOffset);
+      setNumNonZeroRegisters(decrementBuckets());
+    }
+  }
+
+  public HyperLogLogCollector fold(HyperLogLogCollector other)
+  {
+    if (other == null || other.storageBuffer.remaining() == 0) {
+      return this;
+    }
+
+    if (storageBuffer.isReadOnly()) {
+      convertToMutableByteBuffer();
+    }
+
+    estimatedCardinality = null;
+
+    if (getRegisterOffset() < other.getRegisterOffset()) {
+      // "Swap" the buffers so that we are folding into the one with the higher offset
+      ByteBuffer newStorage = ByteBuffer.allocate(other.storageBuffer.remaining());
+      newStorage.put(other.storageBuffer.asReadOnlyBuffer());
+      newStorage.clear();
+
+      other.storageBuffer = storageBuffer;
+      other.initPosition = initPosition;
+      storageBuffer = newStorage;
+      initPosition = 0;
+    }
+
+    ByteBuffer otherBuffer = other.storageBuffer.asReadOnlyBuffer();
+    byte otherOffset = other.getRegisterOffset();
+
+    if (storageBuffer.remaining() != getNumBytesForDenseStorage()) {
+      convertToDenseStorage();
+    }
+
+    byte myOffset = getRegisterOffset();
+    short numNonZero = getNumNonZeroRegisters();
+
+    int offsetDiff = myOffset - otherOffset;
+    if (offsetDiff < 0) {
+      throw new ISE("offsetDiff[%d] < 0, shouldn't happen because of swap.", offsetDiff);
+    }
+
+    byte otherOverflowValue = other.getMaxOverflowValue();
+    short otherOverflowRegister = other.getMaxOverflowRegister();
+    add(otherOverflowRegister, otherOverflowValue);
+
+    int myPayloadStart = getPayloadBytePosition();
+    otherBuffer.position(other.getPayloadBytePosition());
+    if (isSparse(otherBuffer)) {
+      while (otherBuffer.hasRemaining()) {
+        short position = otherBuffer.getShort();
+        int payloadStartPosition = position - other.getNumHeaderBytes();
+        numNonZero += mergeAndStoreByteRegister(
+            myPayloadStart + payloadStartPosition,
+            offsetDiff,
+            otherBuffer.get()
+        );
+        if (numNonZero == NUM_BUCKETS) {
+          myOffset += 1;
+          numNonZero = decrementBuckets();
+          setRegisterOffset(myOffset);
+          setNumNonZeroRegisters(numNonZero);
+
+          offsetDiff = myOffset - otherOffset;
+        }
+      }
+    } else { // dense
+      int position = getPayloadBytePosition();
+      while (otherBuffer.hasRemaining()) {
+        numNonZero += mergeAndStoreByteRegister(
+            position,
+            offsetDiff,
+            otherBuffer.get()
+        );
+        if (numNonZero == NUM_BUCKETS) {
+          myOffset += 1;
+          numNonZero = decrementBuckets();
+          setRegisterOffset(myOffset);
+          setNumNonZeroRegisters(numNonZero);
+
+          offsetDiff = myOffset - otherOffset;
+        }
+        position++;
+      }
+    }
+
+    setRegisterOffset(myOffset);
+    setNumNonZeroRegisters(numNonZero);
+
+    return this;
+  }
+
+  public HyperLogLogCollector fold(ByteBuffer buffer)
+  {
+    return fold(makeCollector(buffer));
+  }
+
+  public ByteBuffer toByteBuffer()
+  {
+    short numNonZeroRegisters = getNumNonZeroRegisters();
+
+    // store sparsely
+    if (storageBuffer.remaining() == getNumBytesForDenseStorage() && numNonZeroRegisters < DENSE_THRESHOLD) {
+      ByteBuffer retVal = ByteBuffer.wrap(new byte[numNonZeroRegisters * 3 + getNumHeaderBytes()]);
+      setVersion(retVal);
+      setRegisterOffset(retVal, getRegisterOffset());
+      setNumNonZeroRegisters(retVal, numNonZeroRegisters);
+      setMaxOverflowValue(retVal, getMaxOverflowValue());
+      setMaxOverflowRegister(retVal, getMaxOverflowRegister());
+
+      int startPosition = getPayloadBytePosition();
+      retVal.position(getPayloadBytePosition(retVal));
+      for (int i = startPosition; i < startPosition + NUM_BYTES_FOR_BUCKETS; i++) {
+        if (storageBuffer.get(i) != 0) {
+          retVal.putShort((short) (0xffff & (i - initPosition)));
+          retVal.put(storageBuffer.get(i));
+        }
+      }
+      retVal.rewind();
+      return retVal.asReadOnlyBuffer();
+    }
+
+    return storageBuffer.asReadOnlyBuffer();
+  }
+
+  @JsonValue
+  public byte[] toByteArray()
+  {
+    final ByteBuffer buffer = toByteBuffer();
+    byte[] theBytes = new byte[buffer.remaining()];
+    buffer.get(theBytes);
+
+    return theBytes;
+  }
+
+  public double estimateCardinality()
+  {
+    if (estimatedCardinality == null) {
+      byte registerOffset = getRegisterOffset();
+      byte overflowValue = getMaxOverflowValue();
+      short overflowRegister = getMaxOverflowRegister();
+      short overflowPosition = (short) (overflowRegister >>> 1);
+      boolean isUpperNibble = ((overflowRegister & 0x1) == 0);
+
+      storageBuffer.position(getPayloadBytePosition());
+
+      if (isSparse(storageBuffer)) {
+        estimatedCardinality = estimateSparse(
+            storageBuffer,
+            registerOffset,
+            overflowValue,
+            overflowPosition,
+            isUpperNibble
+        );
+      } else {
+        estimatedCardinality = estimateDense(
+            storageBuffer,
+            registerOffset,
+            overflowValue,
+            overflowPosition,
+            isUpperNibble
+        );
+      }
+
+      storageBuffer.position(initPosition);
+    }
+    return estimatedCardinality;
+  }
+
+  public double estimateByteBuffer(ByteBuffer buf)
+  {
+    return makeCollector(buf).estimateCardinality();
+  }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+
+    HyperLogLogCollector collector = (HyperLogLogCollector) o;
+
+    if (storageBuffer != null ? !storageBuffer.equals(collector.storageBuffer) : collector.storageBuffer != null) {
+      return false;
+    }
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = storageBuffer != null ? storageBuffer.hashCode() : 0;
+    result = 31 * result + initPosition;
+    return result;
+  }
+
+  @Override
+  public String toString()
+  {
+    return "HyperLogLogCollector{" +
+           "initPosition=" + initPosition +
+           ", version=" + getVersion() +
+           ", registerOffset=" + getRegisterOffset() +
+           ", numNonZeroRegisters=" + getNumNonZeroRegisters() +
+           ", maxOverflowValue=" + getMaxOverflowValue() +
+           ", maxOverflowRegister=" + getMaxOverflowRegister() +
+           '}';
+  }
+
+  private short decrementBuckets()
+  {
+    short count = 0;
+    int startPosition = getPayloadBytePosition();
+    for (int i = startPosition; i < startPosition + NUM_BYTES_FOR_BUCKETS; i++) {
+      byte val = (byte) (storageBuffer.get(i) - 0x11);
+      if ((val & 0xf0) != 0) {
+        count++;
+      }
+      if ((val & 0x0f) != 0) {
+        count++;
+      }
+      storageBuffer.put(i, val);
+    }
+    return count;
+  }
+
+  private void convertToMutableByteBuffer()
+  {
+    ByteBuffer tmpBuffer = ByteBuffer.allocate(storageBuffer.remaining());
+    tmpBuffer.put(storageBuffer.asReadOnlyBuffer());
+    tmpBuffer.position(0);
+    storageBuffer = tmpBuffer;
+    initPosition = 0;
+  }
+
+  private void convertToDenseStorage()
+  {
+    ByteBuffer tmpBuffer = ByteBuffer.wrap(new byte[getNumBytesForDenseStorage()]);
+    // put header
+    setVersion(tmpBuffer);
+    setRegisterOffset(tmpBuffer, getRegisterOffset());
+    setNumNonZeroRegisters(tmpBuffer, getNumNonZeroRegisters());
+    setMaxOverflowValue(tmpBuffer, getMaxOverflowValue());
+    setMaxOverflowRegister(tmpBuffer, getMaxOverflowRegister());
+
+    storageBuffer.position(getPayloadBytePosition());
+    tmpBuffer.position(getPayloadBytePosition(tmpBuffer));
+    // put payload
+    while (storageBuffer.hasRemaining()) {
+      tmpBuffer.put(storageBuffer.getShort(), storageBuffer.get());
+    }
+    tmpBuffer.rewind();
+    storageBuffer = tmpBuffer;
+    initPosition = 0;
+  }
+
+  private short addNibbleRegister(short bucket, byte positionOf1)
+  {
+    short numNonZeroRegs = getNumNonZeroRegisters();
+    final short position = (short) (bucket >> 1);
+    final boolean isUpperNibble = ((bucket & 0x1) == 0);
+
+    byte shiftedPositionOf1 = (isUpperNibble) ? (byte) (positionOf1 << bitsPerBucket) : positionOf1;
+
+    if (storageBuffer.remaining() != getNumBytesForDenseStorage()) {
+      convertToDenseStorage();
+    }
+
+    byte origVal = storageBuffer.get(getPayloadBytePosition() + position);
+    byte newValueMask = (isUpperNibble) ? (byte) 0xf0 : (byte) 0x0f;
+    byte originalValueMask = (byte) (newValueMask ^ 0xff);
+
+    // if something was at zero, we have to increase the numNonZeroRegisters
+    if ((origVal & newValueMask) == 0 && shiftedPositionOf1 != 0) {
+      numNonZeroRegs++;
+    }
+
+    storageBuffer.put(
+        getPayloadBytePosition() + position,
+        (byte) (UnsignedBytes.max((byte) (origVal & newValueMask), shiftedPositionOf1) | (origVal & originalValueMask))
+    );
+
+    return numNonZeroRegs;
+  }
+
+  /**
+   * Returns the number of registers that are no longer zero after the value was added
+   *
+   * @param position   The position into the byte buffer, this position represents two "registers"
+   * @param offsetDiff The difference in offset between the byteToAdd and the current HyperLogLogCollector
+   * @param byteToAdd  The byte to merge into the current HyperLogLogCollector
+   *
+   * @return
+   */
+  private int mergeAndStoreByteRegister(
+      int position,
+      int offsetDiff,
+      byte byteToAdd
+  )
+  {
+    if (byteToAdd == 0) {
+      return 0;
+    }
+
+    byte currVal = storageBuffer.get(position);
+
+    int upperNibble = currVal & 0xf0;
+    int lowerNibble = currVal & 0x0f;
+
+    // subtract the differences so that the nibbles align
+    int otherUpper = (byteToAdd & 0xf0) - (offsetDiff << bitsPerBucket);
+    int otherLower = (byteToAdd & 0x0f) - offsetDiff;
+
+    final int newUpper = Math.max(upperNibble, otherUpper);
+    final int newLower = Math.max(lowerNibble, otherLower);
+
+    int numNoLongerZero = 0;
+    if (upperNibble == 0 && newUpper > 0) {
+      ++numNoLongerZero;
+    }
+
+    if (lowerNibble == 0 && newLower > 0) {
+      ++numNoLongerZero;
+    }
+
+    storageBuffer.put(position, (byte) ((newUpper | newLower) & 0xff));
+
+    return numNoLongerZero;
+  }
+
+  @Override
+  public int compareTo(HyperLogLogCollector other)
+  {
+    final int lhsOffset = (int) this.getRegisterOffset() & 0xffff;
+    final int rhsOffset = (int) other.getRegisterOffset() & 0xffff;
+
+    if (lhsOffset == rhsOffset) {
+      final int lhsNumNonZero = (int) this.getNumNonZeroRegisters() & 0xff;
+      final int rhsNumNonZero = (int) this.getNumNonZeroRegisters() & 0xff;
+      int retVal = Double.compare(lhsNumNonZero, rhsNumNonZero);
+
+      if (retVal == 0) {
+        retVal = Double.compare(this.estimateCardinality(), other.estimateCardinality());
+      }
+
+      return retVal;
+    } else {
+      return Double.compare(lhsOffset, rhsOffset);
+    }
+  }
+}

processing/src/main/java/io/druid/query/aggregation/hyperloglog/HyperUniqueFinalizingPostAggregator.java

@@ -0,0 +1,69 @@
+/*
+ * Druid - a distributed column store.
+ * Copyright (C) 2012, 2013  Metamarkets Group Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+package io.druid.query.aggregation.hyperloglog;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.google.common.collect.Sets;
+import io.druid.query.aggregation.PostAggregator;
+
+import java.util.Comparator;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ */
+public class HyperUniqueFinalizingPostAggregator implements PostAggregator
+{
+  private final String fieldName;
+
+  @JsonCreator
+  public HyperUniqueFinalizingPostAggregator(
+      @JsonProperty("fieldName") String fieldName
+  )
+  {
+    this.fieldName = fieldName;
+  }
+
+  @Override
+  public Set<String> getDependentFields()
+  {
+    return Sets.newHashSet(fieldName);
+  }
+
+  @Override
+  public Comparator getComparator()
+  {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public Object compute(Map<String, Object> combinedAggregators)
+  {
+    return HyperUniquesAggregatorFactory.estimateCardinality(combinedAggregators.get(fieldName));
+  }
+
+  @Override
+  @JsonProperty("fieldName")
+  public String getName()
+  {
+    return fieldName;
+  }
+}

processing/src/main/java/io/druid/query/aggregation/hyperloglog/HyperUniquesAggregator.java

@@ -0,0 +1,86 @@
+/*
+ * Druid - a distributed column store.
+ * Copyright (C) 2012, 2013  Metamarkets Group Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+package io.druid.query.aggregation.hyperloglog;
+
+import io.druid.query.aggregation.Aggregator;
+import io.druid.segment.ObjectColumnSelector;
+
+/**
+ */
+public class HyperUniquesAggregator implements Aggregator
+{
+  private final String name;
+  private final ObjectColumnSelector selector;
+
+  private HyperLogLogCollector collector;
+
+  public HyperUniquesAggregator(
+      String name,
+      ObjectColumnSelector selector
+  )
+  {
+    this.name = name;
+    this.selector = selector;
+
+    this.collector = HyperLogLogCollector.makeLatestCollector();
+  }
+
+  @Override
+  public void aggregate()
+  {
+    collector.fold((HyperLogLogCollector) selector.get());
+  }
+
+  @Override
+  public void reset()
+  {
+    collector = HyperLogLogCollector.makeLatestCollector();
+  }
+
+  @Override
+  public Object get()
+  {
+    return collector;
+  }
+
+  @Override
+  public float getFloat()
+  {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public String getName()
+  {
+    return name;
+  }
+
+  @Override
+  public Aggregator clone()
+  {
+    return new HyperUniquesAggregator(name, selector);
+  }
+
+  @Override
+  public void close()
+  {
+    // no resources to cleanup
+  }
+}

processing/src/main/java/io/druid/query/aggregation/hyperloglog/HyperUniquesAggregatorFactory.java

@@ -0,0 +1,232 @@
+/*
+ * Druid - a distributed column store.
+ * Copyright (C) 2012, 2013  Metamarkets Group Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+package io.druid.query.aggregation.hyperloglog;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.google.common.base.Charsets;
+import com.metamx.common.IAE;
+import io.druid.query.aggregation.Aggregator;
+import io.druid.query.aggregation.AggregatorFactory;
+import io.druid.query.aggregation.BufferAggregator;
+import io.druid.query.aggregation.NoopAggregator;
+import io.druid.query.aggregation.NoopBufferAggregator;
+import io.druid.segment.ColumnSelectorFactory;
+import io.druid.segment.ObjectColumnSelector;
+import org.apache.commons.codec.binary.Base64;
+
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.List;
+
+/**
+ */
+public class HyperUniquesAggregatorFactory implements AggregatorFactory
+{
+  public static Object estimateCardinality(Object object)
+  {
+    if (object == null) {
+      return 0;
+    }
+
+    return ((HyperLogLogCollector) object).estimateCardinality();
+  }
+
+  private static final byte CACHE_TYPE_ID = 0x5;
+
+  private final String name;
+  private final String fieldName;
+
+  @JsonCreator
+  public HyperUniquesAggregatorFactory(
+      @JsonProperty("name") String name,
+      @JsonProperty("fieldName") String fieldName
+  )
+  {
+    this.name = name;
+    this.fieldName = fieldName.toLowerCase();
+  }
+
+  @Override
+  public Aggregator factorize(ColumnSelectorFactory metricFactory)
+  {
+    ObjectColumnSelector selector = metricFactory.makeObjectColumnSelector(fieldName);
+
+    if (selector == null) {
+      return new NoopAggregator(name);
+    }
+
+    if (HyperLogLogCollector.class.isAssignableFrom(selector.classOfObject())) {
+      return new HyperUniquesAggregator(name, selector);
+    }
+
+    throw new IAE(
+        "Incompatible type for metric[%s], expected a HyperUnique, got a %s", fieldName, selector.classOfObject()
+    );
+  }
+
+  @Override
+  public BufferAggregator factorizeBuffered(ColumnSelectorFactory metricFactory)
+  {
+    ObjectColumnSelector selector = metricFactory.makeObjectColumnSelector(fieldName);
+
+    if (selector == null) {
+      return new NoopBufferAggregator();
+    }
+
+    if (HyperLogLogCollector.class.isAssignableFrom(selector.classOfObject())) {
+      return new HyperUniquesBufferAggregator(selector);
+    }
+
+    throw new IAE(
+        "Incompatible type for metric[%s], expected a HyperUnique, got a %s", fieldName, selector.classOfObject()
+    );
+  }
+
+  @Override
+  public Comparator getComparator()
+  {
+    return new Comparator<HyperLogLogCollector>()
+    {
+      @Override
+      public int compare(HyperLogLogCollector lhs, HyperLogLogCollector rhs)
+      {
+        return lhs.compareTo(rhs);
+      }
+    };
+  }
+
+  @Override
+  public Object combine(Object lhs, Object rhs)
+  {
+    if (rhs == null) {
+      return lhs;
+    }
+    if (lhs == null) {
+      return rhs;
+    }
+    return ((HyperLogLogCollector) lhs).fold((HyperLogLogCollector) rhs);
+  }
+
+  @Override
+  public AggregatorFactory getCombiningFactory()
+  {
+    return new HyperUniquesAggregatorFactory(name, name);
+  }
+
+  @Override
+  public Object deserialize(Object object)
+  {
+    if (object instanceof byte[]) {
+      return HyperLogLogCollector.makeCollector(ByteBuffer.wrap((byte[]) object));
+    } else if (object instanceof ByteBuffer) {
+      return HyperLogLogCollector.makeCollector((ByteBuffer) object);
+    } else if (object instanceof String) {
+      return HyperLogLogCollector.makeCollector(
+          ByteBuffer.wrap(Base64.decodeBase64(((String) object).getBytes(Charsets.UTF_8)))
+      );
+    }
+    return object;
+  }
+
+  @Override
+
+  public Object finalizeComputation(Object object)
+  {
+    return estimateCardinality(object);
+  }
+
+  @Override
+  @JsonProperty
+  public String getName()
+  {
+    return name;
+  }
+
+  @Override
+  public List<String> requiredFields()
+  {
+    return Arrays.asList(fieldName);
+  }
+
+  @JsonProperty
+  public String getFieldName()
+  {
+    return fieldName;
+  }
+
+  @Override
+  public byte[] getCacheKey()
+  {
+    byte[] fieldNameBytes = fieldName.getBytes(Charsets.UTF_8);
+
+    return ByteBuffer.allocate(1 + fieldNameBytes.length).put(CACHE_TYPE_ID).put(fieldNameBytes).array();
+  }
+
+  @Override
+  public String getTypeName()
+  {
+    return "hyperUnique";
+  }
+
+  @Override
+  public int getMaxIntermediateSize()
+  {
+    return HyperLogLogCollector.getLatestNumBytesForDenseStorage();
+  }
+
+  @Override
+  public Object getAggregatorStartValue()
+  {
+    return HyperLogLogCollector.makeLatestCollector();
+  }
+
+  @Override
+  public String toString()
+  {
+    return "HyperUniquesAggregatorFactory{" +
+           "name='" + name + '\'' +
+           ", fieldName='" + fieldName + '\'' +
+           '}';
+  }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    HyperUniquesAggregatorFactory that = (HyperUniquesAggregatorFactory) o;
+
+    if (!fieldName.equals(that.fieldName)) return false;
+    if (!name.equals(that.name)) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = name.hashCode();
+    result = 31 * result + fieldName.hashCode();
+    return result;
+  }
+}

processing/src/main/java/io/druid/query/aggregation/hyperloglog/HyperUniquesBufferAggregator.java

@@ -0,0 +1,87 @@
+/*
+ * Druid - a distributed column store.
+ * Copyright (C) 2012, 2013  Metamarkets Group Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+package io.druid.query.aggregation.hyperloglog;
+
+import io.druid.query.aggregation.BufferAggregator;
+import io.druid.segment.ObjectColumnSelector;
+
+import java.nio.ByteBuffer;
+
+/**
+ */
+public class HyperUniquesBufferAggregator implements BufferAggregator
+{
+  private static final byte[] EMPTY_BYTES = HyperLogLogCollector.makeEmptyVersionedByteArray();
+  private final ObjectColumnSelector selector;
+
+  public HyperUniquesBufferAggregator(
+      ObjectColumnSelector selector
+  )
+  {
+    this.selector = selector;
+  }
+
+  @Override
+  public void init(ByteBuffer buf, int position)
+  {
+    final ByteBuffer mutationBuffer = buf.duplicate();
+    mutationBuffer.position(position);
+    mutationBuffer.put(EMPTY_BYTES);
+  }
+
+  @Override
+  public void aggregate(ByteBuffer buf, int position)
+  {
+    HyperLogLogCollector collector = (HyperLogLogCollector) selector.get();
+
+    if (collector == null) {
+      return;
+    }
+
+    HyperLogLogCollector.makeCollector(
+        (ByteBuffer) buf.duplicate().position(position).limit(
+            position
+            + HyperLogLogCollector.getLatestNumBytesForDenseStorage()
+        )
+    ).fold(collector);
+  }
+
+  @Override
+  public Object get(ByteBuffer buf, int position)
+  {
+    ByteBuffer dataCopyBuffer = ByteBuffer.allocate(HyperLogLogCollector.getLatestNumBytesForDenseStorage());
+    ByteBuffer mutationBuffer = buf.duplicate();
+    mutationBuffer.position(position);
+    mutationBuffer.get(dataCopyBuffer.array());
+    return HyperLogLogCollector.makeCollector(dataCopyBuffer);
+  }
+
+  @Override
+  public float getFloat(ByteBuffer buf, int position)
+  {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public void close()
+  {
+    // no resources to cleanup
+  }
+}

processing/src/main/java/io/druid/query/aggregation/hyperloglog/HyperUniquesSerde.java

@@ -0,0 +1,148 @@
+/*
+ * Druid - a distributed column store.
+ * Copyright (C) 2012, 2013  Metamarkets Group Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+package io.druid.query.aggregation.hyperloglog;
+
+import com.google.common.base.Charsets;
+import com.google.common.collect.Ordering;
+import com.google.common.hash.HashFunction;
+import io.druid.data.input.InputRow;
+import io.druid.segment.column.ColumnBuilder;
+import io.druid.segment.data.GenericIndexed;
+import io.druid.segment.data.ObjectStrategy;
+import io.druid.segment.serde.ColumnPartSerde;
+import io.druid.segment.serde.ComplexColumnPartSerde;
+import io.druid.segment.serde.ComplexColumnPartSupplier;
+import io.druid.segment.serde.ComplexMetricExtractor;
+import io.druid.segment.serde.ComplexMetricSerde;
+
+import java.nio.ByteBuffer;
+import java.util.List;
+
+/**
+ */
+public class HyperUniquesSerde extends ComplexMetricSerde
+{
+  private static Ordering<HyperLogLogCollector> comparator = new Ordering<HyperLogLogCollector>()
+  {
+    @Override
+    public int compare(
+        HyperLogLogCollector arg1, HyperLogLogCollector arg2
+    )
+    {
+      return arg1.toByteBuffer().compareTo(arg2.toByteBuffer());
+    }
+  }.nullsFirst();
+
+  private final HashFunction hashFn;
+
+  public HyperUniquesSerde(
+      HashFunction hashFn
+  )
+  {
+    this.hashFn = hashFn;
+  }
+
+  @Override
+  public String getTypeName()
+  {
+    return "hyperUnique";
+  }
+
+  @Override
+  public ComplexMetricExtractor getExtractor()
+  {
+    return new ComplexMetricExtractor()
+    {
+      @Override
+      public Class<HyperLogLogCollector> extractedClass()
+      {
+        return HyperLogLogCollector.class;
+      }
+
+      @Override
+      public HyperLogLogCollector extractValue(InputRow inputRow, String metricName)
+      {
+        HyperLogLogCollector collector = HyperLogLogCollector.makeLatestCollector();
+
+        List<String> dimValues = inputRow.getDimension(metricName);
+        if (dimValues == null) {
+          return collector;
+        }
+
+        for (String dimensionValue : dimValues) {
+          collector.add(hashFn.hashBytes(dimensionValue.getBytes(Charsets.UTF_8)).asBytes());
+        }
+        return collector;
+      }
+    };
+  }
+
+  @Override
+  public ColumnPartSerde deserializeColumn(
+      ByteBuffer byteBuffer, ColumnBuilder columnBuilder
+  )
+  {
+    final GenericIndexed column = GenericIndexed.read(byteBuffer, getObjectStrategy());
+
+    columnBuilder.setComplexColumn(new ComplexColumnPartSupplier(getTypeName(), column));
+
+    return new ComplexColumnPartSerde(column, getTypeName());
+  }
+
+  @Override
+  public ObjectStrategy getObjectStrategy()
+  {
+    return new ObjectStrategy<HyperLogLogCollector>()
+    {
+      @Override
+      public Class<? extends HyperLogLogCollector> getClazz()
+      {
+        return HyperLogLogCollector.class;
+      }
+
+      @Override
+      public HyperLogLogCollector fromByteBuffer(ByteBuffer buffer, int numBytes)
+      {
+        buffer.limit(buffer.position() + numBytes);
+
+        int remaining = buffer.remaining();
+        return (remaining % 3 == 0 || remaining == 1027) ? new HLLCV0(buffer) : new HLLCV1(buffer);
+      }
+
+      @Override
+      public byte[] toBytes(HyperLogLogCollector collector)
+      {
+        if (collector == null) {
+          return new byte[]{};
+        }
+        ByteBuffer val = collector.toByteBuffer();
+        byte[] retVal = new byte[val.remaining()];
+        val.asReadOnlyBuffer().get(retVal);
+        return retVal;
+      }
+
+      @Override
+      public int compare(HyperLogLogCollector o1, HyperLogLogCollector o2)
+      {
+        return comparator.compare(o1, o2);
+      }
+    };
+  }
+}

processing/src/main/java/io/druid/query/aggregation/post/ArithmeticPostAggregator.java

@@ -193,4 +193,30 @@ public class ArithmeticPostAggregator implements PostAggregator
       return lookupMap.keySet();
     }
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    ArithmeticPostAggregator that = (ArithmeticPostAggregator) o;
+
+    if (fields != null ? !fields.equals(that.fields) : that.fields != null) return false;
+    if (fnName != null ? !fnName.equals(that.fnName) : that.fnName != null) return false;
+    if (name != null ? !name.equals(that.name) : that.name != null) return false;
+    if (op != that.op) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = name != null ? name.hashCode() : 0;
+    result = 31 * result + (fnName != null ? fnName.hashCode() : 0);
+    result = 31 * result + (fields != null ? fields.hashCode() : 0);
+    result = 31 * result + (op != null ? op.hashCode() : 0);
+    return result;
+  }
 }

processing/src/main/java/io/druid/query/aggregation/post/ConstantPostAggregator.java

@@ -77,7 +77,7 @@ public class ConstantPostAggregator implements PostAggregator
     return name;
   }
 
-  @JsonProperty
+  @JsonProperty("value")
   public Number getConstantValue()
   {
     return constantValue;
@@ -91,4 +91,39 @@ public class ConstantPostAggregator implements PostAggregator
            ", constantValue=" + constantValue +
            '}';
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+
+    ConstantPostAggregator that = (ConstantPostAggregator) o;
+
+    if (constantValue != null && that.constantValue != null) {
+      if (constantValue.doubleValue() != that.constantValue.doubleValue()) {
+        return false;
+      }
+    } else if (constantValue != that.constantValue) {
+      return false;
+    }
+
+    if (name != null ? !name.equals(that.name) : that.name != null) {
+      return false;
+    }
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = name != null ? name.hashCode() : 0;
+    result = 31 * result + (constantValue != null ? constantValue.hashCode() : 0);
+    return result;
+  }
 }

processing/src/main/java/io/druid/query/aggregation/post/FieldAccessPostAggregator.java

@@ -84,4 +84,26 @@ public class FieldAccessPostAggregator implements PostAggregator
            ", fieldName='" + fieldName + '\'' +
            '}';
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    FieldAccessPostAggregator that = (FieldAccessPostAggregator) o;
+
+    if (fieldName != null ? !fieldName.equals(that.fieldName) : that.fieldName != null) return false;
+    if (name != null ? !name.equals(that.name) : that.name != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = name != null ? name.hashCode() : 0;
+    result = 31 * result + (fieldName != null ? fieldName.hashCode() : 0);
+    return result;
+  }
 }

processing/src/main/java/io/druid/query/aggregation/post/JavaScriptPostAggregator.java

@@ -142,4 +142,30 @@ public class JavaScriptPostAggregator implements PostAggregator
   {
     return function;
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    JavaScriptPostAggregator that = (JavaScriptPostAggregator) o;
+
+    if (fieldNames != null ? !fieldNames.equals(that.fieldNames) : that.fieldNames != null) return false;
+    if (fn != null ? !fn.equals(that.fn) : that.fn != null) return false;
+    if (function != null ? !function.equals(that.function) : that.function != null) return false;
+    if (name != null ? !name.equals(that.name) : that.name != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = name != null ? name.hashCode() : 0;
+    result = 31 * result + (fieldNames != null ? fieldNames.hashCode() : 0);
+    result = 31 * result + (function != null ? function.hashCode() : 0);
+    result = 31 * result + (fn != null ? fn.hashCode() : 0);
+    return result;
+  }
 }

processing/src/main/java/io/druid/query/dimension/DefaultDimensionSpec.java

@@ -84,4 +84,26 @@ public class DefaultDimensionSpec implements DimensionSpec
            ", outputName='" + outputName + '\'' +
            '}';
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    DefaultDimensionSpec that = (DefaultDimensionSpec) o;
+
+    if (dimension != null ? !dimension.equals(that.dimension) : that.dimension != null) return false;
+    if (outputName != null ? !outputName.equals(that.outputName) : that.outputName != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = dimension != null ? dimension.hashCode() : 0;
+    result = 31 * result + (outputName != null ? outputName.hashCode() : 0);
+    return result;
+  }
 }

processing/src/main/java/io/druid/query/dimension/ExtractionDimensionSpec.java

@@ -92,4 +92,29 @@ public class ExtractionDimensionSpec implements DimensionSpec
            ", outputName='" + outputName + '\'' +
            '}';
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    ExtractionDimensionSpec that = (ExtractionDimensionSpec) o;
+
+    if (dimExtractionFn != null ? !dimExtractionFn.equals(that.dimExtractionFn) : that.dimExtractionFn != null)
+      return false;
+    if (dimension != null ? !dimension.equals(that.dimension) : that.dimension != null) return false;
+    if (outputName != null ? !outputName.equals(that.outputName) : that.outputName != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = dimension != null ? dimension.hashCode() : 0;
+    result = 31 * result + (dimExtractionFn != null ? dimExtractionFn.hashCode() : 0);
+    result = 31 * result + (outputName != null ? outputName.hashCode() : 0);
+    return result;
+  }
 }

processing/src/main/java/io/druid/query/groupby/GroupByQuery.java

@@ -33,7 +33,11 @@ import com.metamx.common.guava.Sequences;
 import io.druid.data.input.Row;
 import io.druid.granularity.QueryGranularity;
 import io.druid.query.BaseQuery;
+import io.druid.query.DataSource;
 import io.druid.query.Queries;
+import io.druid.query.Query;
+import io.druid.query.QueryDataSource;
+import io.druid.query.TableDataSource;
 import io.druid.query.aggregation.AggregatorFactory;
 import io.druid.query.aggregation.PostAggregator;
 import io.druid.query.dimension.DefaultDimensionSpec;
@@ -72,7 +76,7 @@ public class GroupByQuery extends BaseQuery<Row>
 
   @JsonCreator
   public GroupByQuery(
-      @JsonProperty("dataSource") String dataSource,
+      @JsonProperty("dataSource") DataSource dataSource,
       @JsonProperty("intervals") QuerySegmentSpec querySegmentSpec,
       @JsonProperty("filter") DimFilter dimFilter,
       @JsonProperty("granularity") QueryGranularity granularity,
@@ -133,7 +137,7 @@ public class GroupByQuery extends BaseQuery<Row>
    * have already passed in order for the object to exist.
    */
   private GroupByQuery(
-      String dataSource,
+      DataSource dataSource,
       QuerySegmentSpec querySegmentSpec,
       DimFilter dimFilter,
       QueryGranularity granularity,
@@ -255,7 +259,7 @@ public class GroupByQuery extends BaseQuery<Row>
 
   public static class Builder
   {
-    private String dataSource;
+    private DataSource dataSource;
     private QuerySegmentSpec querySegmentSpec;
     private DimFilter dimFilter;
     private QueryGranularity granularity;
@@ -270,7 +274,9 @@ public class GroupByQuery extends BaseQuery<Row>
     private List<OrderByColumnSpec> orderByColumnSpecs = Lists.newArrayList();
     private int limit = Integer.MAX_VALUE;
 
-    private Builder() {}
+    private Builder()
+    {
+    }
 
     private Builder(Builder builder)
     {
@@ -288,12 +294,24 @@ public class GroupByQuery extends BaseQuery<Row>
       context = builder.context;
     }
 
-    public Builder setDataSource(String dataSource)
+    public Builder setDataSource(DataSource dataSource)
     {
       this.dataSource = dataSource;
       return this;
     }
 
+    public Builder setDataSource(String dataSource)
+    {
+      this.dataSource = new TableDataSource(dataSource);
+      return this;
+    }
+
+    public Builder setDataSource(Query query)
+    {
+      this.dataSource = new QueryDataSource(query);
+      return this;
+    }
+
     public Builder setInterval(Object interval)
     {
       return setQuerySegmentSpec(new LegacySegmentSpec(interval));
@@ -479,13 +497,52 @@ public class GroupByQuery extends BaseQuery<Row>
   public String toString()
   {
     return "GroupByQuery{" +
-           "limitSpec=" + limitSpec +
-           ", dimFilter=" + dimFilter +
-           ", granularity=" + granularity +
-           ", dimensions=" + dimensions +
-           ", aggregatorSpecs=" + aggregatorSpecs +
-           ", postAggregatorSpecs=" + postAggregatorSpecs +
-           ", orderByLimitFn=" + orderByLimitFn +
-           '}';
+        "limitSpec=" + limitSpec +
+        ", dimFilter=" + dimFilter +
+        ", granularity=" + granularity +
+        ", dimensions=" + dimensions +
+        ", aggregatorSpecs=" + aggregatorSpecs +
+        ", postAggregatorSpecs=" + postAggregatorSpecs +
+        ", orderByLimitFn=" + orderByLimitFn +
+        '}';
+  }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+    if (!super.equals(o)) return false;
+
+    GroupByQuery that = (GroupByQuery) o;
+
+    if (aggregatorSpecs != null ? !aggregatorSpecs.equals(that.aggregatorSpecs) : that.aggregatorSpecs != null)
+      return false;
+    if (dimFilter != null ? !dimFilter.equals(that.dimFilter) : that.dimFilter != null) return false;
+    if (dimensions != null ? !dimensions.equals(that.dimensions) : that.dimensions != null) return false;
+    if (granularity != null ? !granularity.equals(that.granularity) : that.granularity != null) return false;
+    if (havingSpec != null ? !havingSpec.equals(that.havingSpec) : that.havingSpec != null) return false;
+    if (limitSpec != null ? !limitSpec.equals(that.limitSpec) : that.limitSpec != null) return false;
+    if (orderByLimitFn != null ? !orderByLimitFn.equals(that.orderByLimitFn) : that.orderByLimitFn != null)
+      return false;
+    if (postAggregatorSpecs != null ? !postAggregatorSpecs.equals(that.postAggregatorSpecs) : that.postAggregatorSpecs != null)
+      return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = super.hashCode();
+    result = 31 * result + (limitSpec != null ? limitSpec.hashCode() : 0);
+    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 + (orderByLimitFn != null ? orderByLimitFn.hashCode() : 0);
+    return result;
   }
 }

processing/src/main/java/io/druid/query/groupby/GroupByQueryHelper.java

@@ -24,9 +24,6 @@ import com.google.common.collect.Lists;
 import com.metamx.common.ISE;
 import com.metamx.common.Pair;
 import com.metamx.common.guava.Accumulator;
-import com.metamx.common.guava.Sequence;
-import com.metamx.common.guava.Sequences;
-import io.druid.data.input.MapBasedRow;
 import io.druid.data.input.Row;
 import io.druid.data.input.Rows;
 import io.druid.granularity.QueryGranularity;

processing/src/main/java/io/druid/query/groupby/GroupByQueryQueryToolChest.java

@@ -34,13 +34,17 @@ import com.metamx.common.guava.Sequences;
 import com.metamx.emitter.service.ServiceMetricEvent;
 import io.druid.data.input.MapBasedRow;
 import io.druid.data.input.Row;
+import io.druid.query.DataSource;
 import io.druid.query.IntervalChunkingQueryRunner;
 import io.druid.query.Query;
+import io.druid.query.QueryDataSource;
 import io.druid.query.QueryRunner;
 import io.druid.query.QueryToolChest;
+import io.druid.query.SubqueryQueryRunner;
 import io.druid.query.aggregation.AggregatorFactory;
 import io.druid.query.aggregation.MetricManipulationFn;
 import io.druid.segment.incremental.IncrementalIndex;
+import io.druid.segment.incremental.IncrementalIndexStorageAdapter;
 import org.joda.time.Interval;
 import org.joda.time.Minutes;
 
@@ -56,13 +60,16 @@ public class GroupByQueryQueryToolChest extends QueryToolChest<Row, GroupByQuery
   private static final String GROUP_BY_MERGE_KEY = "groupByMerge";
   private static final Map<String, String> NO_MERGE_CONTEXT = ImmutableMap.of(GROUP_BY_MERGE_KEY, "false");
   private final Supplier<GroupByQueryConfig> configSupplier;
+  private GroupByQueryEngine engine; // For running the outer query around a subquery
 
   @Inject
   public GroupByQueryQueryToolChest(
-      Supplier<GroupByQueryConfig> configSupplier
+      Supplier<GroupByQueryConfig> configSupplier,
+      GroupByQueryEngine engine
   )
   {
     this.configSupplier = configSupplier;
+    this.engine = engine;
   }
 
   @Override
@@ -84,13 +91,32 @@ public class GroupByQueryQueryToolChest extends QueryToolChest<Row, GroupByQuery
 
   private Sequence<Row> mergeGroupByResults(final GroupByQuery query, QueryRunner<Row> runner)
   {
-    final GroupByQueryConfig config = configSupplier.get();
-    Pair<IncrementalIndex, Accumulator<IncrementalIndex, Row>> indexAccumulatorPair = GroupByQueryHelper.createIndexAccumulatorPair(
-        query,
-        config
-    );
 
-    IncrementalIndex index = runner.run(query).accumulate(indexAccumulatorPair.lhs, indexAccumulatorPair.rhs);
+    Sequence<Row> result;
+
+    // If there's a subquery, merge subquery results and then apply the aggregator
+    DataSource dataSource = query.getDataSource();
+    if (dataSource instanceof QueryDataSource) {
+      GroupByQuery subquery;
+      try {
+        subquery = (GroupByQuery) ((QueryDataSource) dataSource).getQuery();
+      } catch (ClassCastException e) {
+        throw new UnsupportedOperationException("Subqueries must be of type 'group by'");
+      }
+      Sequence<Row> subqueryResult = mergeGroupByResults(subquery, runner);
+      IncrementalIndexStorageAdapter adapter
+          = new IncrementalIndexStorageAdapter(makeIncrementalIndex(subquery, subqueryResult));
+      result = engine.process(query, adapter);
+    } else {
+      result = runner.run(query);
+    }
+
+    return postAggregate(query, makeIncrementalIndex(query, result));
+  }
+
+
+  private Sequence<Row> postAggregate(final GroupByQuery query, IncrementalIndex index)
+  {
     Sequence<Row> sequence = Sequences.map(
         Sequences.simple(index.iterableWithPostAggregations(query.getPostAggregatorSpecs())),
         new Function<Row, Row>()
@@ -101,7 +127,7 @@ public class GroupByQueryQueryToolChest extends QueryToolChest<Row, GroupByQuery
             final MapBasedRow row = (MapBasedRow) input;
             return new MapBasedRow(
                 query.getGranularity()
-                     .toDateTime(row.getTimestampFromEpoch()),
+                    .toDateTime(row.getTimestampFromEpoch()),
                 row.getEvent()
             );
           }
@@ -110,6 +136,18 @@ public class GroupByQueryQueryToolChest extends QueryToolChest<Row, GroupByQuery
     return query.applyLimit(sequence);
   }
 
+  private IncrementalIndex makeIncrementalIndex(GroupByQuery query, Sequence<Row> rows)
+  {
+    final GroupByQueryConfig config = configSupplier.get();
+    Pair<IncrementalIndex, Accumulator<IncrementalIndex, Row>> indexAccumulatorPair = GroupByQueryHelper.createIndexAccumulatorPair(
+        query,
+        config
+    );
+
+    return rows.accumulate(indexAccumulatorPair.lhs, indexAccumulatorPair.rhs);
+  }
+
+
   @Override
   public Sequence<Row> mergeSequences(Sequence<Sequence<Row>> seqOfSequences)
   {
@@ -125,7 +163,7 @@ public class GroupByQueryQueryToolChest extends QueryToolChest<Row, GroupByQuery
     }
 
     return new ServiceMetricEvent.Builder()
-        .setUser2(query.getDataSource())
+        .setUser2(query.getDataSource().toString())
         .setUser3(String.format("%,d dims", query.getDimensions().size()))
         .setUser4("groupBy")
         .setUser5(Joiner.on(",").join(query.getIntervals()))
@@ -165,6 +203,7 @@ public class GroupByQueryQueryToolChest extends QueryToolChest<Row, GroupByQuery
   @Override
   public QueryRunner<Row> preMergeQueryDecoration(QueryRunner<Row> runner)
   {
-    return new IntervalChunkingQueryRunner<Row>(runner, configSupplier.get().getChunkPeriod());
+    return new SubqueryQueryRunner<Row>(
+        new IntervalChunkingQueryRunner<Row>(runner, configSupplier.get().getChunkPeriod()));
   }
 }

processing/src/main/java/io/druid/query/groupby/orderby/DefaultLimitSpec.java

@@ -196,6 +196,25 @@ public class DefaultLimitSpec implements LimitSpec
     {
       return Sequences.limit(input, limit);
     }
+
+    @Override
+    public boolean equals(Object o)
+    {
+      if (this == o) return true;
+      if (o == null || getClass() != o.getClass()) return false;
+
+      LimitingFn that = (LimitingFn) o;
+
+      if (limit != that.limit) return false;
+
+      return true;
+    }
+
+    @Override
+    public int hashCode()
+    {
+      return limit;
+    }
   }
 
   private static class SortingFn implements Function<Sequence<Row>, Sequence<Row>>
@@ -209,6 +228,25 @@ public class DefaultLimitSpec implements LimitSpec
     {
       return Sequences.sort(input, ordering);
     }
+
+    @Override
+    public boolean equals(Object o)
+    {
+      if (this == o) return true;
+      if (o == null || getClass() != o.getClass()) return false;
+
+      SortingFn sortingFn = (SortingFn) o;
+
+      if (ordering != null ? !ordering.equals(sortingFn.ordering) : sortingFn.ordering != null) return false;
+
+      return true;
+    }
+
+    @Override
+    public int hashCode()
+    {
+      return ordering != null ? ordering.hashCode() : 0;
+    }
   }
 
   private static class TopNFunction implements Function<Sequence<Row>, Sequence<Row>>
@@ -231,5 +269,49 @@ public class DefaultLimitSpec implements LimitSpec
       final ArrayList<Row> materializedList = Sequences.toList(input, Lists.<Row>newArrayList());
       return Sequences.simple(sorter.toTopN(materializedList, limit));
     }
+
+    @Override
+    public boolean equals(Object o)
+    {
+      if (this == o) return true;
+      if (o == null || getClass() != o.getClass()) return false;
+
+      TopNFunction that = (TopNFunction) o;
+
+      if (limit != that.limit) return false;
+      if (sorter != null ? !sorter.equals(that.sorter) : that.sorter != null) return false;
+
+      return true;
+    }
+
+    @Override
+    public int hashCode()
+    {
+      int result = sorter != null ? sorter.hashCode() : 0;
+      result = 31 * result + limit;
+      return result;
+    }
+  }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    DefaultLimitSpec that = (DefaultLimitSpec) o;
+
+    if (limit != that.limit) return false;
+    if (columns != null ? !columns.equals(that.columns) : that.columns != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = columns != null ? columns.hashCode() : 0;
+    result = 31 * result + limit;
+    return result;
   }
 }

processing/src/main/java/io/druid/query/groupby/orderby/NoopLimitSpec.java

@@ -46,4 +46,15 @@ public class NoopLimitSpec implements LimitSpec
   {
     return "NoopLimitSpec";
   }
+
+  @Override
+  public boolean equals(Object other)
+  {
+    return (other instanceof NoopLimitSpec);
+  }
+
+  @Override
+  public int hashCode() {
+    return 0;
+  }
 }

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

@@ -147,7 +147,7 @@ public class SegmentMetadataQueryQueryToolChest extends QueryToolChest<SegmentAn
     }
 
     return new ServiceMetricEvent.Builder()
-        .setUser2(query.getDataSource())
+        .setUser2(query.getDataSource().toString())
         .setUser4(query.getType())
         .setUser5(Joiner.on(",").join(query.getIntervals()))
         .setUser6(String.valueOf(query.hasFilters()))
@@ -179,9 +179,9 @@ public class SegmentMetadataQueryQueryToolChest extends QueryToolChest<SegmentAn
       {
         byte[] includerBytes = query.getToInclude().getCacheKey();
         return ByteBuffer.allocate(1 + includerBytes.length)
-                         .put(SEGMENT_METADATA_CACHE_PREFIX)
-                         .put(includerBytes)
-                         .array();
+            .put(SEGMENT_METADATA_CACHE_PREFIX)
+            .put(includerBytes)
+            .array();
       }
 
       @Override

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

@@ -23,6 +23,7 @@ import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import io.druid.query.BaseQuery;
 import io.druid.query.Query;
+import io.druid.query.TableDataSource;
 import io.druid.query.spec.QuerySegmentSpec;
 
 import java.util.Map;
@@ -42,7 +43,7 @@ public class SegmentMetadataQuery extends BaseQuery<SegmentAnalysis>
       @JsonProperty("context") Map<String, String> context
   )
   {
-    super(dataSource, querySegmentSpec, context);
+    super(new TableDataSource(dataSource), querySegmentSpec, context);
 
     this.toInclude = toInclude == null ? new AllColumnIncluderator() : toInclude;
     this.merge = merge == null ? false : merge;
@@ -76,13 +77,40 @@ public class SegmentMetadataQuery extends BaseQuery<SegmentAnalysis>
   public Query<SegmentAnalysis> withOverriddenContext(Map<String, String> contextOverride)
   {
     return new SegmentMetadataQuery(
-        getDataSource(), getQuerySegmentSpec(), toInclude, merge, computeOverridenContext(contextOverride)
+        ((TableDataSource)getDataSource()).getName(),
+        getQuerySegmentSpec(), toInclude, merge, computeOverridenContext(contextOverride)
     );
   }
 
   @Override
   public Query<SegmentAnalysis> withQuerySegmentSpec(QuerySegmentSpec spec)
   {
-    return new SegmentMetadataQuery(getDataSource(), spec, toInclude, merge, getContext());
+    return new SegmentMetadataQuery(
+        ((TableDataSource)getDataSource()).getName(),
+        spec, toInclude, merge, getContext());
+  }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+    if (!super.equals(o)) return false;
+
+    SegmentMetadataQuery that = (SegmentMetadataQuery) o;
+
+    if (merge != that.merge) return false;
+    if (toInclude != null ? !toInclude.equals(that.toInclude) : that.toInclude != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = super.hashCode();
+    result = 31 * result + (toInclude != null ? toInclude.hashCode() : 0);
+    result = 31 * result + (merge ? 1 : 0);
+    return result;
   }
 }

processing/src/main/java/io/druid/query/search/SearchQueryQueryToolChest.java

@@ -121,7 +121,7 @@ public class SearchQueryQueryToolChest extends QueryToolChest<Result<SearchResul
     }
 
     return new ServiceMetricEvent.Builder()
-        .setUser2(query.getDataSource())
+        .setUser2(query.getDataSource().toString())
         .setUser4("search")
         .setUser5(COMMA_JOIN.join(query.getIntervals()))
         .setUser6(String.valueOf(query.hasFilters()))
@@ -173,7 +173,7 @@ public class SearchQueryQueryToolChest extends QueryToolChest<Result<SearchResul
         final ByteBuffer queryCacheKey = ByteBuffer
             .allocate(
                 1 + 4 + granularityBytes.length + filterBytes.length +
-                querySpecBytes.length + dimensionsBytesSize
+                    querySpecBytes.length + dimensionsBytesSize
             )
             .put(SEARCH_QUERY)
             .put(Ints.toByteArray(query.getLimit()))

processing/src/main/java/io/druid/query/search/search/FragmentSearchQuerySpec.java

@@ -99,4 +99,23 @@ public class FragmentSearchQuerySpec implements SearchQuerySpec
              "values=" + values +
            "}";
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    FragmentSearchQuerySpec that = (FragmentSearchQuerySpec) o;
+
+    if (values != null ? !values.equals(that.values) : that.values != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    return values != null ? values.hashCode() : 0;
+  }
 }

processing/src/main/java/io/druid/query/search/search/InsensitiveContainsSearchQuerySpec.java

@@ -73,4 +73,23 @@ public class InsensitiveContainsSearchQuerySpec implements SearchQuerySpec
            "value=" + value +
            "}";
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    InsensitiveContainsSearchQuerySpec that = (InsensitiveContainsSearchQuerySpec) o;
+
+    if (value != null ? !value.equals(that.value) : that.value != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    return value != null ? value.hashCode() : 0;
+  }
 }

processing/src/main/java/io/druid/query/search/search/LexicographicSearchSortSpec.java

@@ -50,4 +50,9 @@ public class LexicographicSearchSortSpec implements SearchSortSpec
   {
     return "lexicographicSort";
   }
+
+  @Override
+  public boolean equals(Object other) {
+    return (other instanceof LexicographicSearchSortSpec);
+  }
 }

processing/src/main/java/io/druid/query/search/search/SearchQuery.java

@@ -26,6 +26,7 @@ import com.google.common.base.Preconditions;
 import com.google.common.collect.Lists;
 import io.druid.granularity.QueryGranularity;
 import io.druid.query.BaseQuery;
+import io.druid.query.DataSource;
 import io.druid.query.Query;
 import io.druid.query.Result;
 import io.druid.query.filter.DimFilter;
@@ -49,7 +50,7 @@ public class SearchQuery extends BaseQuery<Result<SearchResultValue>>
 
   @JsonCreator
   public SearchQuery(
-      @JsonProperty("dataSource") String dataSource,
+      @JsonProperty("dataSource") DataSource dataSource,
       @JsonProperty("filter") DimFilter dimFilter,
       @JsonProperty("granularity") QueryGranularity granularity,
       @JsonProperty("limit") int limit,
@@ -181,13 +182,45 @@ public class SearchQuery extends BaseQuery<Result<SearchResultValue>>
   public String toString()
   {
     return "SearchQuery{" +
-           "dataSource='" + getDataSource() + '\'' +
-           ", dimFilter=" + dimFilter +
-           ", granularity='" + granularity + '\'' +
-           ", dimensions=" + dimensions +
-           ", querySpec=" + querySpec +
-           ", querySegmentSpec=" + getQuerySegmentSpec() +
-           ", limit=" + limit +
-           '}';
+        "dataSource='" + getDataSource() + '\'' +
+        ", dimFilter=" + dimFilter +
+        ", granularity='" + granularity + '\'' +
+        ", dimensions=" + dimensions +
+        ", querySpec=" + querySpec +
+        ", querySegmentSpec=" + getQuerySegmentSpec() +
+        ", limit=" + limit +
+        '}';
+  }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+    if (!super.equals(o)) return false;
+
+    SearchQuery that = (SearchQuery) o;
+
+    if (limit != that.limit) return false;
+    if (dimFilter != null ? !dimFilter.equals(that.dimFilter) : that.dimFilter != null) return false;
+    if (dimensions != null ? !dimensions.equals(that.dimensions) : that.dimensions != null) return false;
+    if (granularity != null ? !granularity.equals(that.granularity) : that.granularity != null) return false;
+    if (querySpec != null ? !querySpec.equals(that.querySpec) : that.querySpec != null) return false;
+    if (sortSpec != null ? !sortSpec.equals(that.sortSpec) : that.sortSpec != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = super.hashCode();
+    result = 31 * result + (dimFilter != null ? dimFilter.hashCode() : 0);
+    result = 31 * result + (sortSpec != null ? sortSpec.hashCode() : 0);
+    result = 31 * result + (granularity != null ? granularity.hashCode() : 0);
+    result = 31 * result + (dimensions != null ? dimensions.hashCode() : 0);
+    result = 31 * result + (querySpec != null ? querySpec.hashCode() : 0);
+    result = 31 * result + limit;
+    return result;
   }
 }

processing/src/main/java/io/druid/query/select/SelectQuery.java

@@ -24,6 +24,7 @@ import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonTypeName;
 import io.druid.granularity.QueryGranularity;
 import io.druid.query.BaseQuery;
+import io.druid.query.DataSource;
 import io.druid.query.Query;
 import io.druid.query.Result;
 import io.druid.query.filter.DimFilter;
@@ -45,7 +46,7 @@ public class SelectQuery extends BaseQuery<Result<SelectResultValue>>
 
   @JsonCreator
   public SelectQuery(
-      @JsonProperty("dataSource") String dataSource,
+      @JsonProperty("dataSource") DataSource dataSource,
       @JsonProperty("intervals") QuerySegmentSpec querySegmentSpec,
       @JsonProperty("filter") DimFilter dimFilter,
       @JsonProperty("granularity") QueryGranularity granularity,
@@ -146,4 +147,34 @@ public class SelectQuery extends BaseQuery<Result<SelectResultValue>>
            ", pagingSpec=" + pagingSpec +
            '}';
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+    if (!super.equals(o)) return false;
+
+    SelectQuery that = (SelectQuery) o;
+
+    if (dimFilter != null ? !dimFilter.equals(that.dimFilter) : that.dimFilter != null) return false;
+    if (dimensions != null ? !dimensions.equals(that.dimensions) : that.dimensions != null) return false;
+    if (granularity != null ? !granularity.equals(that.granularity) : that.granularity != null) return false;
+    if (metrics != null ? !metrics.equals(that.metrics) : that.metrics != null) return false;
+    if (pagingSpec != null ? !pagingSpec.equals(that.pagingSpec) : that.pagingSpec != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = super.hashCode();
+    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 + (metrics != null ? metrics.hashCode() : 0);
+    result = 31 * result + (pagingSpec != null ? pagingSpec.hashCode() : 0);
+    return result;
+  }
 }

processing/src/main/java/io/druid/query/select/SelectQueryQueryToolChest.java

@@ -123,7 +123,7 @@ public class SelectQueryQueryToolChest extends QueryToolChest<Result<SelectResul
     }
 
     return new ServiceMetricEvent.Builder()
-        .setUser2(query.getDataSource())
+        .setUser2(query.getDataSource().toString())
         .setUser4("Select")
         .setUser5(COMMA_JOIN.join(query.getIntervals()))
         .setUser6(String.valueOf(query.hasFilters()))

processing/src/main/java/io/druid/query/spec/MultipleIntervalSegmentSpec.java

@@ -64,4 +64,23 @@ public class MultipleIntervalSegmentSpec implements QuerySegmentSpec
            "intervals=" + intervals +
            '}';
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    MultipleIntervalSegmentSpec that = (MultipleIntervalSegmentSpec) o;
+
+    if (intervals != null ? !intervals.equals(that.intervals) : that.intervals != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    return intervals != null ? intervals.hashCode() : 0;
+  }
 }

processing/src/main/java/io/druid/query/spec/MultipleSpecificSegmentSpec.java

@@ -91,4 +91,26 @@ public class MultipleSpecificSegmentSpec implements QuerySegmentSpec
            "descriptors=" + descriptors +
            '}';
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    MultipleSpecificSegmentSpec that = (MultipleSpecificSegmentSpec) o;
+
+    if (descriptors != null ? !descriptors.equals(that.descriptors) : that.descriptors != null) return false;
+    if (intervals != null ? !intervals.equals(that.intervals) : that.intervals != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = descriptors != null ? descriptors.hashCode() : 0;
+    result = 31 * result + (intervals != null ? intervals.hashCode() : 0);
+    return result;
+  }
 }

processing/src/main/java/io/druid/query/spec/SpecificSegmentSpec.java

@@ -51,4 +51,23 @@ public class SpecificSegmentSpec implements QuerySegmentSpec
   {
     return walker.getQueryRunnerForSegments(query, Arrays.asList(descriptor));
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    SpecificSegmentSpec that = (SpecificSegmentSpec) o;
+
+    if (descriptor != null ? !descriptor.equals(that.descriptor) : that.descriptor != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    return descriptor != null ? descriptor.hashCode() : 0;
+  }
 }

processing/src/main/java/io/druid/query/timeboundary/TimeBoundaryQuery.java

@@ -25,6 +25,7 @@ import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import io.druid.query.BaseQuery;
+import io.druid.query.DataSource;
 import io.druid.query.Query;
 import io.druid.query.Result;
 import io.druid.query.spec.MultipleIntervalSegmentSpec;
@@ -51,7 +52,7 @@ public class TimeBoundaryQuery extends BaseQuery<Result<TimeBoundaryResultValue>
 
   @JsonCreator
   public TimeBoundaryQuery(
-      @JsonProperty("dataSource") String dataSource,
+      @JsonProperty("dataSource") DataSource dataSource,
       @JsonProperty("intervals") QuerySegmentSpec querySegmentSpec,
       @JsonProperty("context") Map<String, String> context
   )

processing/src/main/java/io/druid/query/timeboundary/TimeBoundaryQueryQueryToolChest.java

@@ -78,7 +78,7 @@ public class TimeBoundaryQueryQueryToolChest
               public boolean apply(T input)
               {
                 return input.getInterval().overlaps(first.getInterval()) || input.getInterval()
-                                                                                 .overlaps(second.getInterval());
+                    .overlaps(second.getInterval());
               }
             }
         )
@@ -117,7 +117,7 @@ public class TimeBoundaryQueryQueryToolChest
   public ServiceMetricEvent.Builder makeMetricBuilder(TimeBoundaryQuery query)
   {
     return new ServiceMetricEvent.Builder()
-        .setUser2(query.getDataSource())
+        .setUser2(query.getDataSource().toString())
         .setUser4(query.getType())
         .setUser6("false")
         .setUser10(query.getId());
@@ -146,9 +146,9 @@ public class TimeBoundaryQueryQueryToolChest
       public byte[] computeCacheKey(TimeBoundaryQuery query)
       {
         return ByteBuffer.allocate(2)
-                         .put(TIMEBOUNDARY_QUERY)
-                         .put(query.getCacheKey())
-                         .array();
+            .put(TIMEBOUNDARY_QUERY)
+            .put(query.getCacheKey())
+            .array();
       }
 
       @Override

processing/src/main/java/io/druid/query/timeseries/TimeseriesQuery.java

@@ -25,6 +25,7 @@ import com.fasterxml.jackson.annotation.JsonTypeName;
 import com.google.common.collect.ImmutableList;
 import io.druid.granularity.QueryGranularity;
 import io.druid.query.BaseQuery;
+import io.druid.query.DataSource;
 import io.druid.query.Queries;
 import io.druid.query.Query;
 import io.druid.query.Result;
@@ -48,7 +49,7 @@ public class TimeseriesQuery extends BaseQuery<Result<TimeseriesResultValue>>
 
   @JsonCreator
   public TimeseriesQuery(
-      @JsonProperty("dataSource") String dataSource,
+      @JsonProperty("dataSource") DataSource dataSource,
       @JsonProperty("intervals") QuerySegmentSpec querySegmentSpec,
       @JsonProperty("filter") DimFilter dimFilter,
       @JsonProperty("granularity") QueryGranularity granularity,
@@ -132,14 +133,43 @@ public class TimeseriesQuery extends BaseQuery<Result<TimeseriesResultValue>>
   public String toString()
   {
     return "TimeseriesQuery{" +
-           "dataSource='" + getDataSource() + '\'' +
-           ", querySegmentSpec=" + getQuerySegmentSpec() +
-           ", dimFilter=" + dimFilter +
-           ", granularity='" + granularity + '\'' +
-           ", aggregatorSpecs=" + aggregatorSpecs +
-           ", postAggregatorSpecs=" + postAggregatorSpecs +
-           ", context=" + getContext() +
-           '}';
+        "dataSource='" + getDataSource() + '\'' +
+        ", querySegmentSpec=" + getQuerySegmentSpec() +
+        ", dimFilter=" + dimFilter +
+        ", granularity='" + granularity + '\'' +
+        ", aggregatorSpecs=" + aggregatorSpecs +
+        ", postAggregatorSpecs=" + postAggregatorSpecs +
+        ", context=" + getContext() +
+        '}';
   }
 
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+    if (!super.equals(o)) return false;
+
+    TimeseriesQuery that = (TimeseriesQuery) o;
+
+    if (aggregatorSpecs != null ? !aggregatorSpecs.equals(that.aggregatorSpecs) : that.aggregatorSpecs != null)
+      return false;
+    if (dimFilter != null ? !dimFilter.equals(that.dimFilter) : that.dimFilter != null) return false;
+    if (granularity != null ? !granularity.equals(that.granularity) : that.granularity != null) return false;
+    if (postAggregatorSpecs != null ? !postAggregatorSpecs.equals(that.postAggregatorSpecs) : that.postAggregatorSpecs != null)
+      return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = super.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;
+  }
 }

processing/src/main/java/io/druid/query/timeseries/TimeseriesQueryQueryToolChest.java

@@ -123,7 +123,7 @@ public class TimeseriesQueryQueryToolChest extends QueryToolChest<Result<Timeser
     }
 
     return new ServiceMetricEvent.Builder()
-        .setUser2(query.getDataSource())
+        .setUser2(query.getDataSource().toString())
         .setUser4("timeseries")
         .setUser5(COMMA_JOIN.join(query.getIntervals()))
         .setUser6(String.valueOf(query.hasFilters()))

processing/src/main/java/io/druid/query/topn/AggregateTopNMetricFirstAlgorithm.java

@@ -79,7 +79,17 @@ public class AggregateTopNMetricFirstAlgorithm implements TopNAlgorithm<int[], T
   )
   {
     final TopNResultBuilder singleMetricResultBuilder = makeResultBuilder(params);
-    final String metric = ((NumericTopNMetricSpec) query.getTopNMetricSpec()).getMetric();
+    final String metric;
+    // ugly
+    TopNMetricSpec spec = query.getTopNMetricSpec();
+    if (spec instanceof InvertedTopNMetricSpec
+        && ((InvertedTopNMetricSpec) spec).getDelegate() instanceof NumericTopNMetricSpec) {
+      metric = ((NumericTopNMetricSpec) ((InvertedTopNMetricSpec) spec).getDelegate()).getMetric();
+    } else if (spec instanceof NumericTopNMetricSpec) {
+      metric = ((NumericTopNMetricSpec) query.getTopNMetricSpec()).getMetric();
+    } else {
+      throw new ISE("WTF?! We are in AggregateTopNMetricFirstAlgorithm with a [%s] spec", spec.getClass().getName());
+    }
 
     // Find either the aggregator or post aggregator to do the topN over
     List<AggregatorFactory> condensedAggs = Lists.newArrayList();

processing/src/main/java/io/druid/query/topn/BaseTopNAlgorithm.java

@@ -78,8 +78,6 @@ public abstract class BaseTopNAlgorithm<DimValSelector, DimValAggregateStore, Pa
     while (numProcessed < cardinality) {
       final int numToProcess = Math.min(params.getNumValuesPerPass(), cardinality - numProcessed);
 
-      params.getCursor().reset();
-
       DimValSelector theDimValSelector;
       if (!hasDimValSelector) {
         theDimValSelector = makeDimValSelector(params, numProcessed, numToProcess);
@@ -96,6 +94,7 @@ public abstract class BaseTopNAlgorithm<DimValSelector, DimValAggregateStore, Pa
       closeAggregators(aggregatesStore);
 
       numProcessed += numToProcess;
+      params.getCursor().reset();
     }
   }
 

processing/src/main/java/io/druid/query/topn/InvertedTopNMetricSpec.java

@@ -101,4 +101,23 @@ public class InvertedTopNMetricSpec implements TopNMetricSpec
   {
     delegate.initTopNAlgorithmSelector(selector);
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    InvertedTopNMetricSpec that = (InvertedTopNMetricSpec) o;
+
+    if (delegate != null ? !delegate.equals(that.delegate) : that.delegate != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    return delegate != null ? delegate.hashCode() : 0;
+  }
 }

processing/src/main/java/io/druid/query/topn/LexicographicTopNMetricSpec.java

@@ -118,4 +118,23 @@ public class LexicographicTopNMetricSpec implements TopNMetricSpec
            "previousStop='" + previousStop + '\'' +
            '}';
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    LexicographicTopNMetricSpec that = (LexicographicTopNMetricSpec) o;
+
+    if (previousStop != null ? !previousStop.equals(that.previousStop) : that.previousStop != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    return previousStop != null ? previousStop.hashCode() : 0;
+  }
 }

processing/src/main/java/io/druid/query/topn/NumericTopNMetricSpec.java

@@ -157,4 +157,23 @@ public class NumericTopNMetricSpec implements TopNMetricSpec
            "metric='" + metric + '\'' +
            '}';
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    NumericTopNMetricSpec that = (NumericTopNMetricSpec) o;
+
+    if (metric != null ? !metric.equals(that.metric) : that.metric != null) return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    return metric != null ? metric.hashCode() : 0;
+  }
 }

processing/src/main/java/io/druid/query/topn/TopNQuery.java

@@ -25,6 +25,7 @@ import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import io.druid.granularity.QueryGranularity;
 import io.druid.query.BaseQuery;
+import io.druid.query.DataSource;
 import io.druid.query.Queries;
 import io.druid.query.Result;
 import io.druid.query.aggregation.AggregatorFactory;
@@ -52,7 +53,7 @@ public class TopNQuery extends BaseQuery<Result<TopNResultValue>>
 
   @JsonCreator
   public TopNQuery(
-      @JsonProperty("dataSource") String dataSource,
+      @JsonProperty("dataSource") DataSource dataSource,
       @JsonProperty("dimension") DimensionSpec dimensionSpec,
       @JsonProperty("metric") TopNMetricSpec topNMetricSpec,
       @JsonProperty("threshold") int threshold,
@@ -208,4 +209,42 @@ public class TopNQuery extends BaseQuery<Result<TopNResultValue>>
            ", postAggregatorSpecs=" + postAggregatorSpecs +
            '}';
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+    if (!super.equals(o)) return false;
+
+    TopNQuery topNQuery = (TopNQuery) o;
+
+    if (threshold != topNQuery.threshold) return false;
+    if (aggregatorSpecs != null ? !aggregatorSpecs.equals(topNQuery.aggregatorSpecs) : topNQuery.aggregatorSpecs != null)
+      return false;
+    if (dimFilter != null ? !dimFilter.equals(topNQuery.dimFilter) : topNQuery.dimFilter != null) return false;
+    if (dimensionSpec != null ? !dimensionSpec.equals(topNQuery.dimensionSpec) : topNQuery.dimensionSpec != null)
+      return false;
+    if (granularity != null ? !granularity.equals(topNQuery.granularity) : topNQuery.granularity != null) return false;
+    if (postAggregatorSpecs != null ? !postAggregatorSpecs.equals(topNQuery.postAggregatorSpecs) : topNQuery.postAggregatorSpecs != null)
+      return false;
+    if (topNMetricSpec != null ? !topNMetricSpec.equals(topNQuery.topNMetricSpec) : topNQuery.topNMetricSpec != null)
+      return false;
+
+    return true;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = super.hashCode();
+    result = 31 * result + (dimensionSpec != null ? dimensionSpec.hashCode() : 0);
+    result = 31 * result + (topNMetricSpec != null ? topNMetricSpec.hashCode() : 0);
+    result = 31 * result + threshold;
+    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;
+  }
 }

processing/src/main/java/io/druid/query/topn/TopNQueryBuilder.java

@@ -21,6 +21,8 @@ package io.druid.query.topn;
 
 import com.google.common.collect.Lists;
 import io.druid.granularity.QueryGranularity;
+import io.druid.query.DataSource;
+import io.druid.query.TableDataSource;
 import io.druid.query.aggregation.AggregatorFactory;
 import io.druid.query.aggregation.PostAggregator;
 import io.druid.query.dimension.DefaultDimensionSpec;
@@ -58,7 +60,7 @@ import java.util.Map;
  */
 public class TopNQueryBuilder
 {
-  private String dataSource;
+  private DataSource dataSource;
   private DimensionSpec dimensionSpec;
   private TopNMetricSpec topNMetricSpec;
   private int threshold;
@@ -71,7 +73,7 @@ public class TopNQueryBuilder
 
   public TopNQueryBuilder()
   {
-    dataSource = "";
+    dataSource = null;
     dimensionSpec = null;
     topNMetricSpec = null;
     threshold = 0;
@@ -83,7 +85,7 @@ public class TopNQueryBuilder
     context = null;
   }
 
-  public String getDataSource()
+  public DataSource getDataSource()
   {
     return dataSource;
   }
@@ -152,7 +154,7 @@ public class TopNQueryBuilder
   public TopNQueryBuilder copy(TopNQuery query)
   {
     return new TopNQueryBuilder()
-        .dataSource(query.getDataSource())
+        .dataSource(query.getDataSource().toString())
         .dimension(query.getDimensionSpec())
         .metric(query.getTopNMetricSpec())
         .threshold(query.getThreshold())
@@ -180,6 +182,12 @@ public class TopNQueryBuilder
   }
 
   public TopNQueryBuilder dataSource(String d)
+  {
+    dataSource = new TableDataSource(d);
+    return this;
+  }
+
+  public TopNQueryBuilder dataSource(DataSource d)
   {
     dataSource = d;
     return this;