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Posted to issues@spark.apache.org by "Josh Rosen (JIRA)" <ji...@apache.org> on 2017/01/06 00:42:58 UTC

[jira] [Created] (SPARK-19093) LeftAntiJoin doesn't seem to resolve cached tables on right side

Josh Rosen created SPARK-19093:
----------------------------------

             Summary: LeftAntiJoin doesn't seem to resolve cached tables on right side
                 Key: SPARK-19093
                 URL: https://issues.apache.org/jira/browse/SPARK-19093
             Project: Spark
          Issue Type: Bug
          Components: SQL
    Affects Versions: 2.1.0
            Reporter: Josh Rosen


See reproduction at https://databricks-prod-cloudfront.cloud.databricks.com/public/4027ec902e239c93eaaa8714f173bcfc/1903098128019500/2699761537338853/1395282846718893/latest.html

Consider the following:

{code}
Seq(("a", "b"), ("c", "d"))
  .toDS
  .write
  .parquet("/tmp/rows")

val df = spark.read.parquet("/tmp/rows")
df.cache()
df.count()
df.createOrReplaceTempView("rows")

spark.sql("""
  select * from rows cross join rows
""").explain(true)

spark.sql("""
  select * from rows where not exists (select * from rows)
""").explain(true)
{code}

In both plans, I'd expect that both sides of the joins would read from the cached table for both the cross join and anti join, but the left anti join produces the following plan which only reads the left side from cache and reads the right side via a regular non-cahced scan:

{code}
== Parsed Logical Plan ==
'Project [*]
+- 'Filter NOT exists#3994
   :  +- 'Project [*]
   :     +- 'UnresolvedRelation `rows`
   +- 'UnresolvedRelation `rows`

== Analyzed Logical Plan ==
_1: string, _2: string
Project [_1#3775, _2#3776]
+- Filter NOT predicate-subquery#3994 []
   :  +- Project [_1#3775 AS _1#3775#4001, _2#3776 AS _2#3776#4002]
   :     +- Project [_1#3775, _2#3776]
   :        +- SubqueryAlias rows
   :           +- Relation[_1#3775,_2#3776] parquet
   +- SubqueryAlias rows
      +- Relation[_1#3775,_2#3776] parquet

== Optimized Logical Plan ==
Join LeftAnti
:- InMemoryRelation [_1#3775, _2#3776], true, 10000, StorageLevel(disk, memory, deserialized, 1 replicas)
:     +- *FileScan parquet [_1#3775,_2#3776] Batched: true, Format: Parquet, Location: InMemoryFileIndex[dbfs:/tmp/rows], PartitionFilters: [], PushedFilters: [], ReadSchema: struct<_1:string,_2:string>
+- Project [_1#3775 AS _1#3775#4001, _2#3776 AS _2#3776#4002]
   +- Relation[_1#3775,_2#3776] parquet

== Physical Plan ==
BroadcastNestedLoopJoin BuildRight, LeftAnti
:- InMemoryTableScan [_1#3775, _2#3776]
:     +- InMemoryRelation [_1#3775, _2#3776], true, 10000, StorageLevel(disk, memory, deserialized, 1 replicas)
:           +- *FileScan parquet [_1#3775,_2#3776] Batched: true, Format: Parquet, Location: InMemoryFileIndex[dbfs:/tmp/rows], PartitionFilters: [], PushedFilters: [], ReadSchema: struct<_1:string,_2:string>
+- BroadcastExchange IdentityBroadcastMode
   +- *Project [_1#3775 AS _1#3775#4001, _2#3776 AS _2#3776#4002]
      +- *FileScan parquet [_1#3775,_2#3776] Batched: true, Format: Parquet, Location: InMemoryFileIndex[dbfs:/tmp/rows], PartitionFilters: [], PushedFilters: [], ReadSchema: struct<_1:string,_2:string>
{code}



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