History

allisonwang-db 4a8dc5f7a3 [SPARK-36747][SQL] Do not collapse Project with Aggregate when correlated subqueries are present in the project list ### What changes were proposed in this pull request? This PR adds a check in the optimizer rule `CollapseProject` to avoid combining Project with Aggregate when the project list contains one or more correlated scalar subqueries that reference the output of the aggregate. Combining Project with Aggregate can lead to an invalid plan after correlated subquery rewrite. This is because correlated scalar subqueries' references are used as join conditions, which cannot host aggregate expressions. For example ```sql select (select sum(c2) from t where c1 = cast(s as int)) from (select sum(c2) s from t) ``` ``` == Optimized Logical Plan == Aggregate [sum(c2)#10L AS scalarsubquery(s)#11L] <--- Aggregate has neither grouping nor aggregate expressions. +- Project [sum(c2)#10L] +- Join LeftOuter, (c1#2 = cast(sum(c2#3) as int)) <--- Aggregate expression in join condition :- LocalRelation [c2#3] +- Aggregate [c1#2], [sum(c2#3) AS sum(c2)#10L, c1#2] +- LocalRelation [c1#2, c2#3] java.lang.UnsupportedOperationException: Cannot generate code for expression: sum(input[0, int, false]) ``` Currently, we only allow a correlated scalar subquery in Aggregate if it is also in the grouping expressions. `079a9c5292/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/optimizer/subquery.scala (L661-L666)` ### Why are the changes needed? To fix an existing optimizer issue. ### Does this PR introduce _any_ user-facing change? No ### How was this patch tested? Unit test. Closes #33990 from allisonwang-db/spark-36747-collapse-agg. Authored-by: allisonwang-db <allison.wang@databricks.com> Signed-off-by: Wenchen Fan <wenchen@databricks.com>		2021-09-23 12:50:27 +08:00
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catalyst	[SPARK-36747][SQL] Do not collapse Project with Aggregate when correlated subqueries are present in the project list	2021-09-23 12:50:27 +08:00
core	[SPARK-36747][SQL] Do not collapse Project with Aggregate when correlated subqueries are present in the project list	2021-09-23 12:50:27 +08:00
hive	[SPARK-32709][SQL] Support writing Hive bucketed table (Parquet/ORC format with Hive hash)	2021-09-17 14:28:51 +08:00
hive-thriftserver	[SPARK-36774][CORE][TESTS] Move SparkSubmitTestUtils to core module and use it in SparkSubmitSuite	2021-09-16 14:28:47 -07:00
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-36657][SQL] Update comment in 'gen-sql-config-docs.py'	2021-09-02 18:50:59 -07:00
gen-sql-functions-docs.py
mkdocs.yml
README.md

README.md

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.