[SPARK-4233] [SPARK-4367] [SPARK-3947] [SPARK-3056] [SQL] Aggregation Improvement

This is the first PR for the aggregation improvement, which is tracked by https://issues.apache.org/jira/browse/SPARK-4366 (umbrella JIRA). This PR contains work for its subtasks, SPARK-3056, SPARK-3947, SPARK-4233, and SPARK-4367.

This PR introduces a new code path for evaluating aggregate functions. This code path is guarded by `spark.sql.useAggregate2` and by default the value of this flag is true.

This new code path contains:
* A new aggregate function interface (`AggregateFunction2`) and 7 built-int aggregate functions based on this new interface (`AVG`, `COUNT`, `FIRST`, `LAST`, `MAX`, `MIN`, `SUM`)
* A UDAF interface (`UserDefinedAggregateFunction`) based on the new code path and two example UDAFs (`MyDoubleAvg` and `MyDoubleSum`).
* A sort-based aggregate operator (`Aggregate2Sort`) for the new aggregate function interface .
* A sort-based aggregate operator (`FinalAndCompleteAggregate2Sort`) for distinct aggregations (for distinct aggregations the query plan will use `Aggregate2Sort` and `FinalAndCompleteAggregate2Sort` together).

With this change, `spark.sql.useAggregate2` is `true`, the flow of compiling an aggregation query is:
1. Our analyzer looks up functions and returns aggregate functions built based on the old aggregate function interface.
2. When our planner is compiling the physical plan, it tries try to convert all aggregate functions to the ones built based on the new interface. The planner will fallback to the old code path if any of the following two conditions is true:
* code-gen is disabled.
* there is any function that cannot be converted (right now, Hive UDAFs).
* the schema of grouping expressions contain any complex data type.
* There are multiple distinct columns.

Right now, the new code path handles a single distinct column in the query (you can have multiple aggregate functions using that distinct column). For a query having a aggregate function with DISTINCT and regular aggregate functions, the generated plan will do partial aggregations for those regular aggregate function.

Thanks chenghao-intel for his initial work on it.

Author: Yin Huai <yhuai@databricks.com>
Author: Michael Armbrust <michael@databricks.com>

Closes #7458 from yhuai/UDAF and squashes the following commits:

7865f5e [Yin Huai] Put the catalyst expression in the comment of the generated code for it.
b04d6c8 [Yin Huai] Remove unnecessary change.
f1d5901 [Yin Huai] Merge remote-tracking branch 'upstream/master' into UDAF
35b0520 [Yin Huai] Use semanticEquals to replace grouping expressions in the output of the aggregate operator.
3b43b24 [Yin Huai] bug fix.
00eb298 [Yin Huai] Make it compile.
a3ca551 [Yin Huai] Merge remote-tracking branch 'upstream/master' into UDAF
e0afca3 [Yin Huai] Gracefully fallback to old aggregation code path.
8a8ac4a [Yin Huai] Merge remote-tracking branch 'upstream/master' into UDAF
88c7d4d [Yin Huai] Enable spark.sql.useAggregate2 by default for testing purpose.
dc96fd1 [Yin Huai] Many updates:
85c9c4b [Yin Huai] newline.
43de3de [Yin Huai] Merge remote-tracking branch 'upstream/master' into UDAF
c3614d7 [Yin Huai] Handle single distinct column.
68b8ee9 [Yin Huai] Support single distinct column set. WIP
3013579 [Yin Huai] Format.
d678aee [Yin Huai] Remove AggregateExpressionSuite.scala since our built-in aggregate functions will be based on AlgebraicAggregate and we need to have another way to test it.
e243ca6 [Yin Huai] Add aggregation iterators.
a101960 [Yin Huai] Change MyJavaUDAF to MyDoubleSum.
594cdf5 [Yin Huai] Change existing AggregateExpression to AggregateExpression1 and add an AggregateExpression as the common interface for both AggregateExpression1 and AggregateExpression2.
380880f [Yin Huai] Merge remote-tracking branch 'upstream/master' into UDAF
0a827b3 [Yin Huai] Add comments and doc. Move some classes to the right places.
a19fea6 [Yin Huai] Add UDAF interface.
262d4c4 [Yin Huai] Make it compile.
b2e358e [Yin Huai] Merge remote-tracking branch 'upstream/master' into UDAF
6edb5ac [Yin Huai] Format update.
70b169c [Yin Huai] Remove groupOrdering.
4721936 [Yin Huai] Add CheckAggregateFunction to extendedCheckRules.
d821a34 [Yin Huai] Cleanup.
32aea9c [Yin Huai] Merge remote-tracking branch 'upstream/master' into UDAF
5b46d41 [Yin Huai] Bug fix.
aff9534 [Yin Huai] Make Aggregate2Sort work with both algebraic AggregateFunctions and non-algebraic AggregateFunctions.
2857b55 [Yin Huai] Merge remote-tracking branch 'upstream/master' into UDAF
4435f20 [Yin Huai] Add ConvertAggregateFunction to HiveContext's analyzer.
1b490ed [Michael Armbrust] make hive test
8cfa6a9 [Michael Armbrust] add test
1b0bb3f [Yin Huai] Do not bind references in AlgebraicAggregate and use code gen for all places.
072209f [Yin Huai] Bug fix: Handle expressions in grouping columns that are not attribute references.
f7d9e54 [Michael Armbrust] Merge remote-tracking branch 'apache/master' into UDAF
39ee975 [Yin Huai] Code cleanup: Remove unnecesary AttributeReferences.
b7720ba [Yin Huai] Add an analysis rule to convert aggregate function to the new version.
5c00f3f [Michael Armbrust] First draft of codegen
6bbc6ba [Michael Armbrust] now with correct answers\!
f7996d0 [Michael Armbrust] Add AlgebraicAggregate
dded1c5 [Yin Huai] wip

2 files changed, 8 insertions, 0 deletions

diff --git a/sql/hive/compatibility/src/test/scala/org/apache/spark/sql/hive/execution/HiveWindowFunctionQuerySuite.scala b/sql/hive/compatibility/src/test/scala/org/apache/spark/sql/hive/execution/HiveWindowFunctionQuerySuite.scala
index 31a49a3683..24a758f531 100644
--- a/sql/hive/compatibility/src/test/scala/org/apache/spark/sql/hive/execution/HiveWindowFunctionQuerySuite.scala
+++ b/sql/hive/compatibility/src/test/scala/org/apache/spark/sql/hive/execution/HiveWindowFunctionQuerySuite.scala
@@ -833,6 +833,7 @@ abstract class HiveWindowFunctionQueryFileBaseSuite
     "windowing_adjust_rowcontainer_sz"
   )
 
+  // Only run those query tests in the realWhileList (do not try other ignored query files).
   override def testCases: Seq[(String, File)] = super.testCases.filter {
     case (name, _) => realWhiteList.contains(name)
   }
diff --git a/sql/hive/compatibility/src/test/scala/org/apache/spark/sql/hive/execution/SortMergeCompatibilitySuite.scala b/sql/hive/compatibility/src/test/scala/org/apache/spark/sql/hive/execution/SortMergeCompatibilitySuite.scala
index f458567e5d..1fe4fe9629 100644
--- a/sql/hive/compatibility/src/test/scala/org/apache/spark/sql/hive/execution/SortMergeCompatibilitySuite.scala
+++ b/sql/hive/compatibility/src/test/scala/org/apache/spark/sql/hive/execution/SortMergeCompatibilitySuite.scala
@@ -17,6 +17,8 @@
 
 package org.apache.spark.sql.hive.execution
 
+import java.io.File
+
 import org.apache.spark.sql.SQLConf
 import org.apache.spark.sql.hive.test.TestHive
 
@@ -159,4 +161,9 @@ class SortMergeCompatibilitySuite extends HiveCompatibilitySuite {
     "join_reorder4",
     "join_star"
   )
+
+  // Only run those query tests in the realWhileList (do not try other ignored query files).
+  override def testCases: Seq[(String, File)] = super.testCases.filter {
+    case (name, _) => realWhiteList.contains(name)
+  }
 }