c79f471d04
## What changes were proposed in this pull request?
Implemented a new SparkPlan that executes the query adaptively. It splits the query plan into independent stages and executes them in order according to their dependencies. The query stage materializes its output at the end. When one stage completes, the data statistics of the materialized output will be used to optimize the remainder of the query.
The adaptive mode is off by default, when turned on, user can see "AdaptiveSparkPlan" as the top node of a query or sub-query. The inner plan of "AdaptiveSparkPlan" is subject to change during query execution but becomes final once the execution is complete. Whether the inner plan is final is included in the EXPLAIN string. Below is an example of the EXPLAIN plan before and after execution:
Query:
```
SELECT * FROM testData JOIN testData2 ON key = a WHERE value = '1'
```
Before execution:
```
== Physical Plan ==
AdaptiveSparkPlan(isFinalPlan=false)
+- SortMergeJoin [key#13], [a#23], Inner
:- Sort [key#13 ASC NULLS FIRST], false, 0
: +- Exchange hashpartitioning(key#13, 5)
: +- Filter (isnotnull(value#14) AND (value#14 = 1))
: +- SerializeFromObject [knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData, true])).key AS key#13, staticinvoke(class org.apache.spark.unsafe.types.UTF8String, StringType, fromString, knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData, true])).value, true, false) AS value#14]
: +- Scan[obj#12]
+- Sort [a#23 ASC NULLS FIRST], false, 0
+- Exchange hashpartitioning(a#23, 5)
+- SerializeFromObject [knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData2, true])).a AS a#23, knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData2, true])).b AS b#24]
+- Scan[obj#22]
```
After execution:
```
== Physical Plan ==
AdaptiveSparkPlan(isFinalPlan=true)
+- *(1) BroadcastHashJoin [key#13], [a#23], Inner, BuildLeft
:- BroadcastQueryStage 2
: +- BroadcastExchange HashedRelationBroadcastMode(List(cast(input[0, int, false] as bigint)))
: +- ShuffleQueryStage 0
: +- Exchange hashpartitioning(key#13, 5)
: +- *(1) Filter (isnotnull(value#14) AND (value#14 = 1))
: +- *(1) SerializeFromObject [knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData, true])).key AS key#13, staticinvoke(class org.apache.spark.unsafe.types.UTF8String, StringType, fromString, knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData, true])).value, true, false) AS value#14]
: +- Scan[obj#12]
+- ShuffleQueryStage 1
+- Exchange hashpartitioning(a#23, 5)
+- *(1) SerializeFromObject [knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData2, true])).a AS a#23, knownnotnull(assertnotnull(input[0, org.apache.spark.sql.test.SQLTestData$TestData2, true])).b AS b#24]
+- Scan[obj#22]
```
Credit also goes to carsonwang and cloud-fan
## How was this patch tested?
Added new UT.
Closes #24706 from maryannxue/aqe.
Authored-by: maryannxue <maryannxue@apache.org>
Signed-off-by: herman <herman@databricks.com>
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|---|---|---|
| .. | ||
| catalyst | ||
| core | ||
| hive | ||
| hive-thriftserver | ||
| create-docs.sh | ||
| gen-sql-markdown.py | ||
| mkdocs.yml | ||
| 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 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 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.