spark-instrumented-optimizer/sql
Ankur Dave 3f2a2b5fe6 [SPARK-33260][SQL] Fix incorrect results from SortExec when sortOrder is Stream
### What changes were proposed in this pull request?

The following query produces incorrect results. The query has two essential features: (1) it contains a string aggregate, resulting in a `SortExec` node, and (2) it contains a duplicate grouping key, causing `RemoveRepetitionFromGroupExpressions` to produce a sort order stored as a `Stream`.

```sql
SELECT bigint_col_1, bigint_col_9, MAX(CAST(bigint_col_1 AS string))
FROM table_4
GROUP BY bigint_col_1, bigint_col_9, bigint_col_9
```

When the sort order is stored as a `Stream`, the line `ordering.map(_.child.genCode(ctx))` in `GenerateOrdering#createOrderKeys()` produces unpredictable side effects to `ctx`. This is because `genCode(ctx)` modifies `ctx`. When ordering is a `Stream`, the modifications will not happen immediately as intended, but will instead occur lazily when the returned `Stream` is used later.

Similar bugs have occurred at least three times in the past: https://issues.apache.org/jira/browse/SPARK-24500, https://issues.apache.org/jira/browse/SPARK-25767, https://issues.apache.org/jira/browse/SPARK-26680.

The fix is to check if `ordering` is a `Stream` and force the modifications to happen immediately if so.

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

No.

### How was this patch tested?

Added a unit test for `SortExec` where `sortOrder` is a `Stream`. The test previously failed and now passes.

Closes #30160 from ankurdave/SPARK-33260.

Authored-by: Ankur Dave <ankurdave@gmail.com>
Signed-off-by: Dongjoon Hyun <dhyun@apple.com>
2020-10-27 13:20:22 -07:00
..
catalyst [SPARK-33260][SQL] Fix incorrect results from SortExec when sortOrder is Stream 2020-10-27 13:20:22 -07:00
core [SPARK-33260][SQL] Fix incorrect results from SortExec when sortOrder is Stream 2020-10-27 13:20:22 -07:00
hive [SPARK-33140][SQL] remove SQLConf and SparkSession in all sub-class of Rule[QueryPlan] 2020-10-27 12:40:57 +00:00
hive-thriftserver [SPARK-33193][SQL][TEST] Hive ThriftServer JDBC Database MetaData API Behavior Auditing 2020-10-23 13:34:33 -07:00
create-docs.sh [SPARK-31550][SQL][DOCS] Set nondeterministic configurations with general meanings in sql configuration doc 2020-04-27 17:08:52 +09:00
gen-sql-api-docs.py [SPARK-31474][SQL][FOLLOWUP] Replace _FUNC_ placeholder with functionname in the note field of expression info 2020-04-23 13:33:04 +09:00
gen-sql-config-docs.py [SPARK-31550][SQL][DOCS] Set nondeterministic configurations with general meanings in sql configuration doc 2020-04-27 17:08:52 +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.