[SPARK-10327][SQL] Cache Table is not working while subquery has alias in its project list

[chenghao-intel]

    import org.apache.spark.sql.hive.execution.HiveTableScan
    sql("select key, value, key + 1 from src").registerTempTable("abc")
    cacheTable("abc")

    val sparkPlan = sql(
      """select a.key, b.key, c.key from
        |abc a join abc b on a.key=b.key
        |join abc c on a.key=c.key""".stripMargin).queryExecution.sparkPlan

    assert(sparkPlan.collect { case e: InMemoryColumnarTableScan => e }.size === 3) // failed
    assert(sparkPlan.collect { case e: HiveTableScan => e }.size === 0) // failed

The actual plan is:

== Parsed Logical Plan ==
'Project [unresolvedalias('a.key),unresolvedalias('b.key),unresolvedalias('c.key)]
 'Join Inner, Some(('a.key = 'c.key))
  'Join Inner, Some(('a.key = 'b.key))
   'UnresolvedRelation [abc], Some(a)
   'UnresolvedRelation [abc], Some(b)
  'UnresolvedRelation [abc], Some(c)

== Analyzed Logical Plan ==
key: int, key: int, key: int
Project [key#14,key#61,key#66]
 Join Inner, Some((key#14 = key#66))
  Join Inner, Some((key#14 = key#61))
   Subquery a
    Subquery abc
     Project [key#14,value#15,(key#14 + 1) AS _c2#16]
      MetastoreRelation default, src, None
   Subquery b
    Subquery abc
     Project [key#61,value#62,(key#61 + 1) AS _c2#58]
      MetastoreRelation default, src, None
  Subquery c
   Subquery abc
    Project [key#66,value#67,(key#66 + 1) AS _c2#63]
     MetastoreRelation default, src, None

== Optimized Logical Plan ==
Project [key#14,key#61,key#66]
 Join Inner, Some((key#14 = key#66))
  Project [key#14,key#61]
   Join Inner, Some((key#14 = key#61))
    Project [key#14]
     InMemoryRelation [key#14,value#15,_c2#16], true, 10000, StorageLevel(true, true, false, true, 1), (Project [key#14,value#15,(key#14 + 1) AS _c2#16]), Some(abc)
    Project [key#61]
     MetastoreRelation default, src, None
  Project [key#66]
   MetastoreRelation default, src, None

== Physical Plan ==
TungstenProject [key#14,key#61,key#66]
 BroadcastHashJoin [key#14], [key#66], BuildRight
  TungstenProject [key#14,key#61]
   BroadcastHashJoin [key#14], [key#61], BuildRight
    ConvertToUnsafe
     InMemoryColumnarTableScan [key#14], (InMemoryRelation [key#14,value#15,_c2#16], true, 10000, StorageLevel(true, true, false, true, 1), (Project [key#14,value#15,(key#14 + 1) AS _c2#16]), Some(abc))
    ConvertToUnsafe
     HiveTableScan [key#61], (MetastoreRelation default, src, None)
  ConvertToUnsafe
   HiveTableScan [key#66], (MetastoreRelation default, src, None)

[chenghao-intel]

cc @marmbrus

[SparkQA]

Test build #41720 has finished for PR 8494 at commit bfd40d9.

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

[marmbrus]

Why does this have ()? It also needs scala doc. However, since its only ever used once, I'd consider just inlining it.

[SparkQA]

Test build #41812 has finished for PR 8494 at commit fc63b89.

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

[SparkQA]

Test build #41852 has finished for PR 8494 at commit b6c0cb9.

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

[marmbrus]

Thanks, merging to master.

[mbautin]

Would it make sense to use transformAllExpressions here instead of enumerating all possible ways of how expressions may occur in the logical plan, or would that produce a different result?

[marmbrus]

Hmmm, yeah that would probably work.