spark-instrumented-optimizer/sql
Yuming Wang 4a6afb4875 [SPARK-36280][SQL] Remove redundant aliases after RewritePredicateSubquery
### What changes were proposed in this pull request?

Remove redundant aliases after `RewritePredicateSubquery`. For example:
```scala
sql("CREATE TABLE t1 USING parquet AS SELECT id AS a, id AS b, id AS c FROM range(10)")
sql("CREATE TABLE t2 USING parquet AS SELECT id AS x, id AS y FROM range(8)")
sql(
  """
    |SELECT *
    |FROM  t1
    |WHERE  a IN (SELECT x
    |  FROM  (SELECT x AS x,
    |           Rank() OVER (partition BY x ORDER BY Sum(y) DESC) AS ranking
    |    FROM   t2
    |    GROUP  BY x) tmp1
    |  WHERE  ranking <= 5)
    |""".stripMargin).explain
```
Before this PR:
```
== Physical Plan ==
AdaptiveSparkPlan isFinalPlan=false
+- BroadcastHashJoin [a#10L], [x#7L], LeftSemi, BuildRight, false
   :- FileScan parquet default.t1[a#10L,b#11L,c#12L]
   +- BroadcastExchange HashedRelationBroadcastMode(List(input[0, bigint, true]),false), [id=#68]
      +- Project [x#7L]
         +- Filter (ranking#8 <= 5)
            +- Window [rank(_w2#25L) windowspecdefinition(x#15L, _w2#25L DESC NULLS LAST, specifiedwindowframe(RowFrame, unboundedpreceding$(), currentrow$())) AS ranking#8], [x#15L], [_w2#25L DESC NULLS LAST]
               +- Sort [x#15L ASC NULLS FIRST, _w2#25L DESC NULLS LAST], false, 0
                  +- Exchange hashpartitioning(x#15L, 5), ENSURE_REQUIREMENTS, [id=#62]
                     +- HashAggregate(keys=[x#15L], functions=[sum(y#16L)])
                        +- Exchange hashpartitioning(x#15L, 5), ENSURE_REQUIREMENTS, [id=#59]
                           +- HashAggregate(keys=[x#15L], functions=[partial_sum(y#16L)])
                              +- FileScan parquet default.t2[x#15L,y#16L]
```

After this PR:
```
== Physical Plan ==
AdaptiveSparkPlan isFinalPlan=false
+- BroadcastHashJoin [a#10L], [x#15L], LeftSemi, BuildRight, false
   :- FileScan parquet default.t1[a#10L,b#11L,c#12L]
   +- BroadcastExchange HashedRelationBroadcastMode(List(input[0, bigint, true]),false), [id=#67]
      +- Project [x#15L]
         +- Filter (ranking#8 <= 5)
            +- Window [rank(_w2#25L) windowspecdefinition(x#15L, _w2#25L DESC NULLS LAST, specifiedwindowframe(RowFrame, unboundedpreceding$(), currentrow$())) AS ranking#8], [x#15L], [_w2#25L DESC NULLS LAST]
               +- Sort [x#15L ASC NULLS FIRST, _w2#25L DESC NULLS LAST], false, 0
                  +- HashAggregate(keys=[x#15L], functions=[sum(y#16L)])
                     +- Exchange hashpartitioning(x#15L, 5), ENSURE_REQUIREMENTS, [id=#59]
                        +- HashAggregate(keys=[x#15L], functions=[partial_sum(y#16L)])
                           +- FileScan parquet default.t2[x#15L,y#16L]
```

### Why are the changes needed?

Reduce shuffle to improve query performance. This change can benefit TPC-DS q70.

### Does this PR introduce _any_ user-facing change?

No.

### How was this patch tested?

Unit test.

Closes #33509 from wangyum/SPARK-36280.

Authored-by: Yuming Wang <yumwang@ebay.com>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
2021-08-03 13:56:59 -07:00
..
catalyst [SPARK-36280][SQL] Remove redundant aliases after RewritePredicateSubquery 2021-08-03 13:56:59 -07:00
core [SPARK-36280][SQL] Remove redundant aliases after RewritePredicateSubquery 2021-08-03 13:56:59 -07:00
hive [SPARK-36349][SQL] Disallow ANSI intervals in file-based datasources 2021-08-03 20:30:20 +03:00
hive-thriftserver [SPARK-36224][SQL] Use Void as the type name of NullType 2021-08-02 23:19:54 +08:00
create-docs.sh [SPARK-34010][SQL][DODCS] Use python3 instead of python in SQL documentation build 2021-01-05 19:48:10 +09:00
gen-sql-api-docs.py [SPARK-34747][SQL][DOCS] Add virtual operators to the built-in function document 2021-03-19 10:19:26 +09:00
gen-sql-config-docs.py [SPARK-32194][PYTHON] Use proper exception classes instead of plain Exception 2021-05-26 11:54:40 +09:00
gen-sql-functions-docs.py [SPARK-31562][SQL] Update ExpressionDescription for substring, current_date, and current_timestamp 2020-04-26 11:46:52 -07:00
mkdocs.yml [SPARK-30731] Update deprecated Mkdocs option 2020-02-19 17:28:58 +09:00
README.md [SPARK-30510][SQL][DOCS] Publicly document Spark SQL configuration options 2020-02-09 19:20:47 +09:00

Spark SQL

This module provides support for executing relational queries expressed in either SQL or the DataFrame/Dataset API.

Spark SQL is broken up into four subprojects:

  • Catalyst (sql/catalyst) - An implementation-agnostic framework for manipulating trees of relational operators and expressions.
  • Execution (sql/core) - A query planner / execution engine for translating Catalyst's logical query plans into Spark RDDs. This component also includes a new public interface, SQLContext, that allows users to execute SQL or LINQ statements against existing RDDs and Parquet files.
  • Hive Support (sql/hive) - Includes extensions that allow users to write queries using a subset of HiveQL and access data from a Hive Metastore using Hive SerDes. There are also wrappers that allow users to run queries that include Hive UDFs, UDAFs, and UDTFs.
  • HiveServer and CLI support (sql/hive-thriftserver) - Includes support for the SQL CLI (bin/spark-sql) and a HiveServer2 (for JDBC/ODBC) compatible server.

Running ./sql/create-docs.sh generates SQL documentation for built-in functions under sql/site, and SQL configuration documentation that gets included as part of configuration.md in the main docs directory.