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[SPARK-22961][REGRESSION] Constant columns should generate QueryPlanConstraints #20155

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adrian-ionescu
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What changes were proposed in this pull request?

#19201 introduced the following regression: given something like df.withColumn("c", lit(2)), we're no longer picking up c === 2 as a constraint and infer filters from it when joins are involved, which may lead to noticeable performance degradation.

This patch re-enables this optimization by picking up Aliases of Literals in Projection lists as constraints and making sure they're not treated as aliased columns.

How was this patch tested?

Unit test was added.

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SparkQA commented Jan 4, 2018

Test build #85687 has finished for PR 20155 at commit 9c8f5c2.

  • This patch passes all tests.
  • This patch merges cleanly.
  • This patch adds no public classes.

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LGTM

@gatorsmile
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Thanks! Merged to master/2.3

asfgit pushed a commit that referenced this pull request Jan 5, 2018
…onstraints

## What changes were proposed in this pull request?

#19201 introduced the following regression: given something like `df.withColumn("c", lit(2))`, we're no longer picking up `c === 2` as a constraint and infer filters from it when joins are involved, which may lead to noticeable performance degradation.

This patch re-enables this optimization by picking up Aliases of Literals in Projection lists as constraints and making sure they're not treated as aliased columns.

## How was this patch tested?

Unit test was added.

Author: Adrian Ionescu <adrian@databricks.com>

Closes #20155 from adrian-ionescu/constant_constraints.

(cherry picked from commit 51c33bd)
Signed-off-by: gatorsmile <gatorsmile@gmail.com>
@asfgit asfgit closed this in 51c33bd Jan 5, 2018
@gengliangwang
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A late LGTM!

asfgit pushed a commit that referenced this pull request Sep 9, 2018
## What changes were proposed in this pull request?
How to reproduce:
```scala
val df1 = spark.createDataFrame(Seq(
   (1, 1)
)).toDF("a", "b").withColumn("c", lit(null).cast("int"))
val df2 = df1.union(df1).withColumn("d", spark_partition_id).filter($"c".isNotNull)
df2.show

+---+---+----+---+
|  a|  b|   c|  d|
+---+---+----+---+
|  1|  1|null|  0|
|  1|  1|null|  1|
+---+---+----+---+
```
`filter($"c".isNotNull)` was transformed to `(null <=> c#10)` before #19201, but it is transformed to `(c#10 = null)` since #20155. This pr revert it to `(null <=> c#10)` to fix this issue.

## How was this patch tested?

unit tests

Closes #22368 from wangyum/SPARK-25368.

Authored-by: Yuming Wang <yumwang@ebay.com>
Signed-off-by: gatorsmile <gatorsmile@gmail.com>
(cherry picked from commit 77c9964)
Signed-off-by: gatorsmile <gatorsmile@gmail.com>
asfgit pushed a commit that referenced this pull request Sep 9, 2018
How to reproduce:
```scala
val df1 = spark.createDataFrame(Seq(
   (1, 1)
)).toDF("a", "b").withColumn("c", lit(null).cast("int"))
val df2 = df1.union(df1).withColumn("d", spark_partition_id).filter($"c".isNotNull)
df2.show

+---+---+----+---+
|  a|  b|   c|  d|
+---+---+----+---+
|  1|  1|null|  0|
|  1|  1|null|  1|
+---+---+----+---+
```
`filter($"c".isNotNull)` was transformed to `(null <=> c#10)` before #19201, but it is transformed to `(c#10 = null)` since #20155. This pr revert it to `(null <=> c#10)` to fix this issue.

unit tests

Closes #22368 from wangyum/SPARK-25368.

Authored-by: Yuming Wang <yumwang@ebay.com>
Signed-off-by: gatorsmile <gatorsmile@gmail.com>
(cherry picked from commit 77c9964)
Signed-off-by: gatorsmile <gatorsmile@gmail.com>
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4 participants