spark-instrumented-optimizer/sql
Marco Gaido 553af22f2c
[SPARK-16323][SQL] Add IntegralDivide expression
## What changes were proposed in this pull request?

The PR takes over #14036 and it introduces a new expression `IntegralDivide` in order to avoid the several unneded cast added previously.

In order to prove the performance gain, the following benchmark has been run:

```
  test("Benchmark IntegralDivide") {
    val r = new scala.util.Random(91)
    val nData = 1000000
    val testDataInt = (1 to nData).map(_ => (r.nextInt(), r.nextInt()))
    val testDataLong = (1 to nData).map(_ => (r.nextLong(), r.nextLong()))
    val testDataShort = (1 to nData).map(_ => (r.nextInt().toShort, r.nextInt().toShort))

    // old code
    val oldExprsInt = testDataInt.map(x =>
      Cast(Divide(Cast(Literal(x._1), DoubleType), Cast(Literal(x._2), DoubleType)), LongType))
    val oldExprsLong = testDataLong.map(x =>
      Cast(Divide(Cast(Literal(x._1), DoubleType), Cast(Literal(x._2), DoubleType)), LongType))
    val oldExprsShort = testDataShort.map(x =>
      Cast(Divide(Cast(Literal(x._1), DoubleType), Cast(Literal(x._2), DoubleType)), LongType))

    // new code
    val newExprsInt = testDataInt.map(x => IntegralDivide(x._1, x._2))
    val newExprsLong = testDataLong.map(x => IntegralDivide(x._1, x._2))
    val newExprsShort = testDataShort.map(x => IntegralDivide(x._1, x._2))

    Seq(("Long", "old", oldExprsLong),
      ("Long", "new", newExprsLong),
      ("Int", "old", oldExprsInt),
      ("Int", "new", newExprsShort),
      ("Short", "old", oldExprsShort),
      ("Short", "new", oldExprsShort)).foreach { case (dt, t, ds) =>
      val start = System.nanoTime()
      ds.foreach(e => e.eval(EmptyRow))
      val endNoCodegen = System.nanoTime()
      println(s"Running $nData op with $t code on $dt (no-codegen): ${(endNoCodegen - start) / 1000000} ms")
    }
  }
```

The results on my laptop are:

```
Running 1000000 op with old code on Long (no-codegen): 600 ms
Running 1000000 op with new code on Long (no-codegen): 112 ms
Running 1000000 op with old code on Int (no-codegen): 560 ms
Running 1000000 op with new code on Int (no-codegen): 135 ms
Running 1000000 op with old code on Short (no-codegen): 317 ms
Running 1000000 op with new code on Short (no-codegen): 153 ms
```

Showing a 2-5X improvement. The benchmark doesn't include code generation as it is pretty hard to test the performance there as for such simple operations the most of the time is spent in the code generation/compilation process.

## How was this patch tested?

added UTs

Closes #22395 from mgaido91/SPARK-16323.

Authored-by: Marco Gaido <marcogaido91@gmail.com>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>
2018-09-17 11:33:50 -07:00
..
catalyst [SPARK-16323][SQL] Add IntegralDivide expression 2018-09-17 11:33:50 -07:00
core [SPARK-16323][SQL] Add IntegralDivide expression 2018-09-17 11:33:50 -07:00
hive [SPARK-25427][SQL][TEST] Add BloomFilter creation test cases 2018-09-17 19:33:51 +08:00
hive-thriftserver [SPARK-25436] Bump master branch version to 2.5.0-SNAPSHOT 2018-09-15 16:24:02 -07:00
create-docs.sh [MINOR][DOCS] Minor doc fixes related with doc build and uses script dir in SQL doc gen script 2017-08-26 13:56:24 +09:00
gen-sql-markdown.py [SPARK-21485][FOLLOWUP][SQL][DOCS] Describes examples and arguments separately, and note/since in SQL built-in function documentation 2017-08-05 10:10:56 -07:00
mkdocs.yml [SPARK-21485][SQL][DOCS] Spark SQL documentation generation for built-in functions 2017-07-26 09:38:51 -07:00
README.md [MINOR][DOC] Fix some typos and grammar issues 2018-04-06 13:37:08 +08:00

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 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.