From bbe0d8caa88cfe5e3cde80b85898a198d785370d Mon Sep 17 00:00:00 2001
From: Stan Zhai <zhaishidan@haizhi.com>
Date: Wed, 1 Mar 2017 07:52:35 -0800
Subject: [PATCH] [SPARK-19766][SQL] Constant alias columns in INNER JOIN
should not be folded by FoldablePropagation rule
## What changes were proposed in this pull request?
This PR fixes the code in Optimizer phase where the constant alias columns of a `INNER JOIN` query are folded in Rule `FoldablePropagation`.
For the following query():
```
val sqlA =
"""
|create temporary view ta as
|select a, 'a' as tag from t1 union all
|select a, 'b' as tag from t2
""".stripMargin
val sqlB =
"""
|create temporary view tb as
|select a, 'a' as tag from t3 union all
|select a, 'b' as tag from t4
""".stripMargin
val sql =
"""
|select tb.* from ta inner join tb on
|ta.a = tb.a and
|ta.tag = tb.tag
""".stripMargin
```
The tag column is an constant alias column, it's folded by `FoldablePropagation` like this:
```
TRACE SparkOptimizer:
=== Applying Rule org.apache.spark.sql.catalyst.optimizer.FoldablePropagation ===
Project [a#4, tag#14] Project [a#4, tag#14]
!+- Join Inner, ((a#0 = a#4) && (tag#8 = tag#14)) +- Join Inner, ((a#0 = a#4) && (a = a))
:- Union :- Union
: :- Project [a#0, a AS tag#8] : :- Project [a#0, a AS tag#8]
: : +- LocalRelation [a#0] : : +- LocalRelation [a#0]
: +- Project [a#2, b AS tag#9] : +- Project [a#2, b AS tag#9]
: +- LocalRelation [a#2] : +- LocalRelation [a#2]
+- Union +- Union
:- Project [a#4, a AS tag#14] :- Project [a#4, a AS tag#14]
: +- LocalRelation [a#4] : +- LocalRelation [a#4]
+- Project [a#6, b AS tag#15] +- Project [a#6, b AS tag#15]
+- LocalRelation [a#6] +- LocalRelation [a#6]
```
Finally the Result of Batch Operator Optimizations is:
```
Project [a#4, tag#14] Project [a#4, tag#14]
!+- Join Inner, ((a#0 = a#4) && (tag#8 = tag#14)) +- Join Inner, (a#0 = a#4)
! :- SubqueryAlias ta, `ta` :- Union
! : +- Union : :- LocalRelation [a#0]
! : :- Project [a#0, a AS tag#8] : +- LocalRelation [a#2]
! : : +- SubqueryAlias t1, `t1` +- Union
! : : +- Project [a#0] :- LocalRelation [a#4, tag#14]
! : : +- SubqueryAlias grouping +- LocalRelation [a#6, tag#15]
! : : +- LocalRelation [a#0]
! : +- Project [a#2, b AS tag#9]
! : +- SubqueryAlias t2, `t2`
! : +- Project [a#2]
! : +- SubqueryAlias grouping
! : +- LocalRelation [a#2]
! +- SubqueryAlias tb, `tb`
! +- Union
! :- Project [a#4, a AS tag#14]
! : +- SubqueryAlias t3, `t3`
! : +- Project [a#4]
! : +- SubqueryAlias grouping
! : +- LocalRelation [a#4]
! +- Project [a#6, b AS tag#15]
! +- SubqueryAlias t4, `t4`
! +- Project [a#6]
! +- SubqueryAlias grouping
! +- LocalRelation [a#6]
```
The condition `tag#8 = tag#14` of INNER JOIN has been removed. This leads to the data of inner join being wrong.
After fix:
```
=== Result of Batch LocalRelation ===
GlobalLimit 21 GlobalLimit 21
+- LocalLimit 21 +- LocalLimit 21
+- Project [a#4, tag#11] +- Project [a#4, tag#11]
+- Join Inner, ((a#0 = a#4) && (tag#8 = tag#11)) +- Join Inner, ((a#0 = a#4) && (tag#8 = tag#11))
! :- SubqueryAlias ta :- Union
! : +- Union : :- LocalRelation [a#0, tag#8]
! : :- Project [a#0, a AS tag#8] : +- LocalRelation [a#2, tag#9]
! : : +- SubqueryAlias t1 +- Union
! : : +- Project [a#0] :- LocalRelation [a#4, tag#11]
! : : +- SubqueryAlias grouping +- LocalRelation [a#6, tag#12]
! : : +- LocalRelation [a#0]
! : +- Project [a#2, b AS tag#9]
! : +- SubqueryAlias t2
! : +- Project [a#2]
! : +- SubqueryAlias grouping
! : +- LocalRelation [a#2]
! +- SubqueryAlias tb
! +- Union
! :- Project [a#4, a AS tag#11]
! : +- SubqueryAlias t3
! : +- Project [a#4]
! : +- SubqueryAlias grouping
! : +- LocalRelation [a#4]
! +- Project [a#6, b AS tag#12]
! +- SubqueryAlias t4
! +- Project [a#6]
! +- SubqueryAlias grouping
! +- LocalRelation [a#6]
```
## How was this patch tested?
add sql-tests/inputs/inner-join.sql
All tests passed.
Author: Stan Zhai <zhaishidan@haizhi.com>
Closes #17099 from stanzhai/fix-inner-join.
(cherry picked from commit 5502a9cf883b2058209904c152e5d2c2a106b072)
Signed-off-by: Xiao Li <gatorsmile@gmail.com>
---
.../sql/catalyst/optimizer/expressions.scala | 2 +-
.../optimizer/FoldablePropagationSuite.scala | 14 ++++
.../resources/sql-tests/inputs/inner-join.sql | 17 +++++
.../sql-tests/results/inner-join.sql.out | 68 +++++++++++++++++++
4 files changed, 100 insertions(+), 1 deletion(-)
create mode 100644 sql/core/src/test/resources/sql-tests/inputs/inner-join.sql
create mode 100644 sql/core/src/test/resources/sql-tests/results/inner-join.sql.out
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/expressions.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/expressions.scala
index 949ccdcb45..243bb592f5 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/expressions.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/expressions.scala
@@ -451,7 +451,7 @@ object FoldablePropagation extends Rule[LogicalPlan] {
// join is not always picked from its children, but can also be null.
// TODO(cloud-fan): It seems more reasonable to use new attributes as the output attributes
// of outer join.
- case j @ Join(_, _, Inner, _) =>
+ case j @ Join(_, _, Inner, _) if !stop =>
j.transformExpressions(replaceFoldable)
// We can fold the projections an expand holds. However expand changes the output columns
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/FoldablePropagationSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/FoldablePropagationSuite.scala
index 82756f545a..d128315b68 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/FoldablePropagationSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/optimizer/FoldablePropagationSuite.scala
@@ -130,6 +130,20 @@ class FoldablePropagationSuite extends PlanTest {
comparePlans(optimized, correctAnswer)
}
+ test("Propagate in inner join") {
+ val ta = testRelation.select('a, Literal(1).as('tag))
+ .union(testRelation.select('a, Literal(2).as('tag)))
+ .subquery('ta)
+ val tb = testRelation.select('a, Literal(1).as('tag))
+ .union(testRelation.select('a, Literal(2).as('tag)))
+ .subquery('tb)
+ val query = ta.join(tb, Inner,
+ Some("ta.a".attr === "tb.a".attr && "ta.tag".attr === "tb.tag".attr))
+ val optimized = Optimize.execute(query.analyze)
+ val correctAnswer = query.analyze
+ comparePlans(optimized, correctAnswer)
+ }
+
test("Propagate in expand") {
val c1 = Literal(1).as('a)
val c2 = Literal(2).as('b)
diff --git a/sql/core/src/test/resources/sql-tests/inputs/inner-join.sql b/sql/core/src/test/resources/sql-tests/inputs/inner-join.sql
new file mode 100644
index 0000000000..38739cb950
--- /dev/null
+++ b/sql/core/src/test/resources/sql-tests/inputs/inner-join.sql
@@ -0,0 +1,17 @@
+CREATE TEMPORARY VIEW t1 AS SELECT * FROM VALUES (1) AS GROUPING(a);
+CREATE TEMPORARY VIEW t2 AS SELECT * FROM VALUES (1) AS GROUPING(a);
+CREATE TEMPORARY VIEW t3 AS SELECT * FROM VALUES (1), (1) AS GROUPING(a);
+CREATE TEMPORARY VIEW t4 AS SELECT * FROM VALUES (1), (1) AS GROUPING(a);
+
+CREATE TEMPORARY VIEW ta AS
+SELECT a, 'a' AS tag FROM t1
+UNION ALL
+SELECT a, 'b' AS tag FROM t2;
+
+CREATE TEMPORARY VIEW tb AS
+SELECT a, 'a' AS tag FROM t3
+UNION ALL
+SELECT a, 'b' AS tag FROM t4;
+
+-- SPARK-19766 Constant alias columns in INNER JOIN should not be folded by FoldablePropagation rule
+SELECT tb.* FROM ta INNER JOIN tb ON ta.a = tb.a AND ta.tag = tb.tag;
diff --git a/sql/core/src/test/resources/sql-tests/results/inner-join.sql.out b/sql/core/src/test/resources/sql-tests/results/inner-join.sql.out
new file mode 100644
index 0000000000..aa20537d44
--- /dev/null
+++ b/sql/core/src/test/resources/sql-tests/results/inner-join.sql.out
@@ -0,0 +1,68 @@
+-- Automatically generated by SQLQueryTestSuite
+-- Number of queries: 13
+
+
+-- !query 0
+CREATE TEMPORARY VIEW t1 AS SELECT * FROM VALUES (1) AS GROUPING(a)
+-- !query 0 schema
+struct<>
+-- !query 0 output
+
+
+
+-- !query 1
+CREATE TEMPORARY VIEW t2 AS SELECT * FROM VALUES (1) AS GROUPING(a)
+-- !query 1 schema
+struct<>
+-- !query 1 output
+
+
+
+-- !query 2
+CREATE TEMPORARY VIEW t3 AS SELECT * FROM VALUES (1), (1) AS GROUPING(a)
+-- !query 2 schema
+struct<>
+-- !query 2 output
+
+
+
+-- !query 3
+CREATE TEMPORARY VIEW t4 AS SELECT * FROM VALUES (1), (1) AS GROUPING(a)
+-- !query 3 schema
+struct<>
+-- !query 3 output
+
+
+
+-- !query 4
+CREATE TEMPORARY VIEW ta AS
+SELECT a, 'a' AS tag FROM t1
+UNION ALL
+SELECT a, 'b' AS tag FROM t2
+-- !query 4 schema
+struct<>
+-- !query 4 output
+
+
+
+-- !query 5
+CREATE TEMPORARY VIEW tb AS
+SELECT a, 'a' AS tag FROM t3
+UNION ALL
+SELECT a, 'b' AS tag FROM t4
+-- !query 5 schema
+struct<>
+-- !query 5 output
+
+
+
+-- !query 6
+SELECT tb.* FROM ta INNER JOIN tb ON ta.a = tb.a AND ta.tag = tb.tag
+-- !query 6 schema
+struct<a:int,tag:string>
+-- !query 6 output
+1 a
+1 a
+1 b
+1 b
+
--
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