spark-instrumented-optimizer/sql
Takeshi YAMAMURO 94922d79e9 [SPARK-17289][SQL] Fix a bug to satisfy sort requirements in partial aggregations
## What changes were proposed in this pull request?
Partial aggregations are generated in `EnsureRequirements`, but the planner fails to
check if partial aggregation satisfies sort requirements.
For the following query:
```
val df2 = (0 to 1000).map(x => (x % 2, x.toString)).toDF("a", "b").createOrReplaceTempView("t2")
spark.sql("select max(b) from t2 group by a").explain(true)
```
Now, the SortAggregator won't insert Sort operator before partial aggregation, this will break sort-based partial aggregation.
```
== Physical Plan ==
SortAggregate(key=[a#5], functions=[max(b#6)], output=[max(b)#17])
+- *Sort [a#5 ASC], false, 0
   +- Exchange hashpartitioning(a#5, 200)
      +- SortAggregate(key=[a#5], functions=[partial_max(b#6)], output=[a#5, max#19])
         +- LocalTableScan [a#5, b#6]
```
Actually, a correct plan is:
```
== Physical Plan ==
SortAggregate(key=[a#5], functions=[max(b#6)], output=[max(b)#17])
+- *Sort [a#5 ASC], false, 0
   +- Exchange hashpartitioning(a#5, 200)
      +- SortAggregate(key=[a#5], functions=[partial_max(b#6)], output=[a#5, max#19])
         +- *Sort [a#5 ASC], false, 0
            +- LocalTableScan [a#5, b#6]
```

## How was this patch tested?
Added tests in `PlannerSuite`.

Author: Takeshi YAMAMURO <linguin.m.s@gmail.com>

Closes #14865 from maropu/SPARK-17289.
2016-08-30 16:43:47 +08:00
..
catalyst [SPARK-17301][SQL] Remove unused classTag field from AtomicType base class 2016-08-30 09:58:00 +08:00
core [SPARK-17289][SQL] Fix a bug to satisfy sort requirements in partial aggregations 2016-08-30 16:43:47 +08:00
hive [SPARK-17063] [SQL] Improve performance of MSCK REPAIR TABLE with Hive metastore 2016-08-29 11:23:53 -07:00
hive-thriftserver [SPARK-17190][SQL] Removal of HiveSharedState 2016-08-25 12:50:03 +08:00
README.md [SPARK-16557][SQL] Remove stale doc in sql/README.md 2016-07-14 19:24:42 -07:00

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 an extension of SQLContext called HiveContext that allows users to write queries using a subset of HiveQL and access data from a Hive Metastore using Hive SerDes. There are also wrappers that allows 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.