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https://issues.apache.org/jira/browse/SPARK-16951?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15412882#comment-15412882
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Nattavut Sutyanyong edited comment on SPARK-16951 at 12/21/16 7:13 PM:
-----------------------------------------------------------------------
The following output is tested on Spark master trunk built on August 5, 2016.
{noformat}
scala> Seq(1,2).toDF("c1").createOrReplaceTempView("t1")
scala> Seq(1).toDF("c2").createOrReplaceTempView("t2")
scala> sql("select t2.c2+1 as c3 from t1 left join t2 on
t1.c1=t2.c2").createOrReplaceTempView("t3")
scala> sql("select * from t1").show
+---+
| c1|
+---+
| 1|
| 2|
+---+
scala> sql("select * from t2").show
+---+
| c2|
+---+
| 1|
+---+
scala> sql("select * from t3").show
+----+
| c3|
+----+
| 2|
|null|
+----+
{noformat}
Case 1:
{noformat}
scala> sql("select * from t3 where c3 not in (select c2 from t2)").show
+----+
| c3|
+----+
| 2|
|null|
+----+
{noformat}
The correct result is:
{noformat}
+----+
| c3|
+----+
| 2|
+----+
{noformat}
Case 2:
{noformat}
scala> sql("select * from t1 where c1 not in (select c3 from t3)").show
+---+
| c1|
+---+
+---+
{noformat}
The answer is correct.
was (Author: nsyca):
The following output is tested on Spark master trunk built on August 5, 2016.
{noformat}
scala> Seq(1,2).toDF("c1").createOrReplaceTempView("t1")
scala> Seq(1).toDF("c2").createOrReplaceTempView("t2")
scala> sql("select t2.c2+1 as c3 from t1 left join t2 on
t1.c1=t2.c2").createOrReplaceTempView("t3")
scala> sql("select * from t1").show
+---+
| c1|
+---+
| 1|
| 2|
+---+
scala> sql("select * from t2").show
+---+
| c2|
+---+
| 1|
+---+
scala> sql("select * from t3").show
+----+
| c3|
+----+
| 2|
|null|
+----+
{noformat}
Case 1:
{noformat}
scala> sql("select * from t3 where c3 not in (select c2 from t2)").show
+----+
| c3|
+----+
| 2|
|null|
+----+
{noformat}
The correct result is:
{noformat}
+----+
| c3|
+----+
| 2|
+----+
{noformat}
Case 2:
{noformat}
scala> sql("select * from t1 where c1 not in (select c3 from t3)").show
+---+
| c1|
+---+
+---+
{noformat}
The answer is correct.
Case 3:
{noformat}
scala> sql("select * from t1 where c1 not in (select c2 from t2 where
1=2)").show
+---+
| c1|
+---+
| 1|
| 2|
+---+
{noformat}
The correct result is:
{noformat}
+---+
| c1|
+---+
+---+
{noformat}
> Alternative implementation of NOT IN to Anti-join
> -------------------------------------------------
>
> Key: SPARK-16951
> URL: https://issues.apache.org/jira/browse/SPARK-16951
> Project: Spark
> Issue Type: Sub-task
> Components: SQL
> Affects Versions: 2.0.0
> Reporter: Nattavut Sutyanyong
>
> A transformation currently used to process {{NOT IN}} subquery is to rewrite
> to a form of Anti-join with null-aware property in the Logical Plan and then
> translate to a form of {{OR}} predicate joining the parent side and the
> subquery side of the {{NOT IN}}. As a result, the presence of {{OR}}
> predicate is limited to the nested-loop join execution plan, which will have
> a major performance implication if both sides' results are large.
> This JIRA sketches an idea of changing the OR predicate to a form similar to
> the technique used in the implementation of the Existence join that addresses
> the problem of {{EXISTS (..) OR ..}} type of queries.
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