[SPARK-2213] [SQL] sort merge join for spark sql

Thanks for the initial work from Ishiihara in #3173

This PR introduce a new join method of sort merge join, which firstly ensure that keys of same value are in the same partition, and inside each partition the Rows are sorted by key. Then we can run down both sides together, find matched rows using [sort merge join](http://en.wikipedia.org/wiki/Sort-merge_join). In this way, we don't have to store the whole hash table of one side as hash join, thus we have less memory usage. Also, this PR would benefit from #3438 , making the sorting phrase much more efficient.

We introduced a new configuration of "spark.sql.planner.sortMergeJoin" to switch between this(`true`) and ShuffledHashJoin(`false`), probably we want the default value of it be `false` at first.

Author: Daoyuan Wang <daoyuan.wang@intel.com>
Author: Michael Armbrust <michael@databricks.com>

This patch had conflicts when merged, resolved by
Committer: Michael Armbrust <michael@databricks.com>

Closes #5208 from adrian-wang/smj and squashes the following commits:

2493b9f [Daoyuan Wang] fix style
5049d88 [Daoyuan Wang] propagate rowOrdering for RangePartitioning
f91a2ae [Daoyuan Wang] yin's comment: use external sort if option is enabled, add comments
f515cd2 [Daoyuan Wang] yin's comment: outputOrdering, join suite refine
ec8061b [Daoyuan Wang] minor change
413fd24 [Daoyuan Wang] Merge pull request #3 from marmbrus/pr/5208
952168a [Michael Armbrust] add type
5492884 [Michael Armbrust] copy when ordering
7ddd656 [Michael Armbrust] Cleanup addition of ordering requirements
b198278 [Daoyuan Wang] inherit ordering in project
c8e82a3 [Daoyuan Wang] fix style
6e897dd [Daoyuan Wang] hide boundReference from manually construct RowOrdering for key compare in smj
8681d73 [Daoyuan Wang] refactor Exchange and fix copy for sorting
2875ef2 [Daoyuan Wang] fix changed configuration
61d7f49 [Daoyuan Wang] add omitted comment
00a4430 [Daoyuan Wang] fix bug
078d69b [Daoyuan Wang] address comments: add comments, do sort in shuffle, and others
3af6ba5 [Daoyuan Wang] use buffer for only one side
171001f [Daoyuan Wang] change default outputordering
47455c9 [Daoyuan Wang] add apache license ...
a28277f [Daoyuan Wang] fix style
645c70b [Daoyuan Wang] address comments using sort
068c35d [Daoyuan Wang] fix new style and add some tests
925203b [Daoyuan Wang] address comments
07ce92f [Daoyuan Wang] fix ArrayIndexOutOfBound
42fca0e [Daoyuan Wang] code clean
e3ec096 [Daoyuan Wang] fix comment style..
2edd235 [Daoyuan Wang] fix outputpartitioning
57baa40 [Daoyuan Wang] fix sort eval bug
303b6da [Daoyuan Wang] fix several errors
95db7ad [Daoyuan Wang] fix brackets for if-statement
4464f16 [Daoyuan Wang] fix error
880d8e9 [Daoyuan Wang] sort merge join for spark sql

2 files changed, 21 insertions, 2 deletions

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/rows.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/rows.scala
index 1b62e17ff4..b6ec7d3417 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/rows.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/rows.scala
@@ -17,8 +17,7 @@
 
 package org.apache.spark.sql.catalyst.expressions
 
-import org.apache.spark.sql.types.{UTF8String, StructType, NativeType}
-
+import org.apache.spark.sql.types.{UTF8String, DataType, StructType, NativeType}
 
 /**
  * An extended interface to [[Row]] that allows the values for each column to be updated.  Setting
@@ -239,3 +238,10 @@ class RowOrdering(ordering: Seq[SortOrder]) extends Ordering[Row] {
     return 0
   }
 }
+
+object RowOrdering {
+  def forSchema(dataTypes: Seq[DataType]): RowOrdering =
+    new RowOrdering(dataTypes.zipWithIndex.map {
+      case(dt, index) => new SortOrder(BoundReference(index, dt, nullable = true), Ascending)
+    })
+}
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/physical/partitioning.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/physical/partitioning.scala
index 288c11f69f..fb4217a448 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/physical/partitioning.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/physical/partitioning.scala
@@ -94,6 +94,9 @@ sealed trait Partitioning {
    * only compatible if the `numPartitions` of them is the same.
    */
   def compatibleWith(other: Partitioning): Boolean
+
+  /** Returns the expressions that are used to key the partitioning. */
+  def keyExpressions: Seq[Expression]
 }
 
 case class UnknownPartitioning(numPartitions: Int) extends Partitioning {
@@ -106,6 +109,8 @@ case class UnknownPartitioning(numPartitions: Int) extends Partitioning {
     case UnknownPartitioning(_) => true
     case _ => false
   }
+
+  override def keyExpressions: Seq[Expression] = Nil
 }
 
 case object SinglePartition extends Partitioning {
@@ -117,6 +122,8 @@ case object SinglePartition extends Partitioning {
     case SinglePartition => true
     case _ => false
   }
+
+  override def keyExpressions: Seq[Expression] = Nil
 }
 
 case object BroadcastPartitioning extends Partitioning {
@@ -128,6 +135,8 @@ case object BroadcastPartitioning extends Partitioning {
     case SinglePartition => true
     case _ => false
   }
+
+  override def keyExpressions: Seq[Expression] = Nil
 }
 
 /**
@@ -158,6 +167,8 @@ case class HashPartitioning(expressions: Seq[Expression], numPartitions: Int)
     case _ => false
   }
 
+  override def keyExpressions: Seq[Expression] = expressions
+
   override def eval(input: Row = null): EvaluatedType =
     throw new TreeNodeException(this, s"No function to evaluate expression. type: ${this.nodeName}")
 }
@@ -200,6 +211,8 @@ case class RangePartitioning(ordering: Seq[SortOrder], numPartitions: Int)
     case _ => false
   }
 
+  override def keyExpressions: Seq[Expression] = ordering.map(_.child)
+
   override def eval(input: Row): EvaluatedType =
     throw new TreeNodeException(this, s"No function to evaluate expression. type: ${this.nodeName}")
 }