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Dongjoon Hyun aef506e39a [SPARK-17739][SQL] Collapse adjacent similar Window operators
## What changes were proposed in this pull request?

Currently, Spark does not collapse adjacent windows with the same partitioning and sorting. This PR implements `CollapseWindow` optimizer to do the followings.

1. If the partition specs and order specs are the same, collapse into the parent.
2. If the partition specs are the same and one order spec is a prefix of the other, collapse to the more specific one.

For example:
```scala
val df = spark.range(1000).select($"id" % 100 as "grp", $"id", rand() as "col1", rand() as "col2")

// Add summary statistics for all columns
import org.apache.spark.sql.expressions.Window
val cols = Seq("id", "col1", "col2")
val window = Window.partitionBy($"grp").orderBy($"id")
val result = cols.foldLeft(df) { (base, name) =>
  base.withColumn(s"${name}_avg", avg(col(name)).over(window))
      .withColumn(s"${name}_stddev", stddev(col(name)).over(window))
      .withColumn(s"${name}_min", min(col(name)).over(window))
      .withColumn(s"${name}_max", max(col(name)).over(window))
}
```

**Before**
```scala
scala> result.explain
== Physical Plan ==
Window [max(col2#19) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col2_max#234], [grp#17L], [id#14L ASC NULLS FIRST]
+- Window [min(col2#19) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col2_min#216], [grp#17L], [id#14L ASC NULLS FIRST]
   +- Window [stddev_samp(col2#19) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col2_stddev#191], [grp#17L], [id#14L ASC NULLS FIRST]
      +- Window [avg(col2#19) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col2_avg#167], [grp#17L], [id#14L ASC NULLS FIRST]
         +- Window [max(col1#18) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col1_max#152], [grp#17L], [id#14L ASC NULLS FIRST]
            +- Window [min(col1#18) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col1_min#138], [grp#17L], [id#14L ASC NULLS FIRST]
               +- Window [stddev_samp(col1#18) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col1_stddev#117], [grp#17L], [id#14L ASC NULLS FIRST]
                  +- Window [avg(col1#18) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col1_avg#97], [grp#17L], [id#14L ASC NULLS FIRST]
                     +- Window [max(id#14L) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS id_max#86L], [grp#17L], [id#14L ASC NULLS FIRST]
                        +- Window [min(id#14L) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS id_min#76L], [grp#17L], [id#14L ASC NULLS FIRST]
                           +- *Project [grp#17L, id#14L, col1#18, col2#19, id_avg#26, id_stddev#42]
                              +- Window [stddev_samp(_w0#59) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS id_stddev#42], [grp#17L], [id#14L ASC NULLS FIRST]
                                 +- *Project [grp#17L, id#14L, col1#18, col2#19, id_avg#26, cast(id#14L as double) AS _w0#59]
                                    +- Window [avg(id#14L) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS id_avg#26], [grp#17L], [id#14L ASC NULLS FIRST]
                                       +- *Sort [grp#17L ASC NULLS FIRST, id#14L ASC NULLS FIRST], false, 0
                                          +- Exchange hashpartitioning(grp#17L, 200)
                                             +- *Project [(id#14L % 100) AS grp#17L, id#14L, rand(-6329949029880411066) AS col1#18, rand(-7251358484380073081) AS col2#19]
                                                +- *Range (0, 1000, step=1, splits=Some(8))
```

**After**
```scala
scala> result.explain
== Physical Plan ==
Window [max(col2#5) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col2_max#220, min(col2#5) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col2_min#202, stddev_samp(col2#5) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col2_stddev#177, avg(col2#5) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col2_avg#153, max(col1#4) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col1_max#138, min(col1#4) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col1_min#124, stddev_samp(col1#4) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col1_stddev#103, avg(col1#4) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col1_avg#83, max(id#0L) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS id_max#72L, min(id#0L) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS id_min#62L], [grp#3L], [id#0L ASC NULLS FIRST]
+- *Project [grp#3L, id#0L, col1#4, col2#5, id_avg#12, id_stddev#28]
   +- Window [stddev_samp(_w0#45) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS id_stddev#28], [grp#3L], [id#0L ASC NULLS FIRST]
      +- *Project [grp#3L, id#0L, col1#4, col2#5, id_avg#12, cast(id#0L as double) AS _w0#45]
         +- Window [avg(id#0L) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS id_avg#12], [grp#3L], [id#0L ASC NULLS FIRST]
            +- *Sort [grp#3L ASC NULLS FIRST, id#0L ASC NULLS FIRST], false, 0
               +- Exchange hashpartitioning(grp#3L, 200)
                  +- *Project [(id#0L % 100) AS grp#3L, id#0L, rand(6537478539664068821) AS col1#4, rand(-8961093871295252795) AS col2#5]
                     +- *Range (0, 1000, step=1, splits=Some(8))
```

## How was this patch tested?

Pass the Jenkins tests with a newly added testsuite.

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #15317 from dongjoon-hyun/SPARK-17739.
2016-09-30 21:05:06 -07:00
.github [MINOR][MAINTENANCE] Fix typo for the pull request template. 2016-02-24 00:45:31 -08:00
assembly [SPARK-16967] move mesos to module 2016-08-26 12:25:22 -07:00
bin [SPARK-16781][PYSPARK] java launched by PySpark as gateway may not be the same java used in the spark environment 2016-08-24 20:04:09 +01:00
build [SPARK-14279][BUILD] Pick the spark version from pom 2016-06-06 09:42:50 -07:00
common [SPARK-15962][SQL] Introduce implementation with a dense format for UnsafeArrayData 2016-09-27 14:18:32 +08:00
conf [SPARK-13238][CORE] Add ganglia dmax parameter 2016-08-05 13:07:52 -07:00
core [SPARK-15353][CORE] Making peer selection for block replication pluggable 2016-09-30 18:24:39 -07:00
data [SPARK-16421][EXAMPLES][ML] Improve ML Example Outputs 2016-08-05 20:57:46 +01:00
dev [SPARK-17651][SPARKR] Set R package version number along with mvn 2016-09-23 14:35:18 -07:00
docs [SPARK-17412][DOC] All test should not be run by root or any admin user 2016-09-29 16:01:45 -07:00
examples [SPARK-14525][SQL] Make DataFrameWrite.save work for jdbc 2016-09-26 09:54:22 +01:00
external [SPARK-17418] Prevent kinesis-asl-assembly artifacts from being published 2016-09-21 11:38:10 -07:00
graphx [SPARK-11496][GRAPHX] Parallel implementation of personalized pagerank 2016-09-10 00:15:59 -07:00
launcher [SPARK-17178][SPARKR][SPARKSUBMIT] Allow to set sparkr shell command through --conf 2016-08-31 00:20:41 -07:00
licenses [MINOR][BUILD] Add modernizr MIT license; specify "2014 and onwards" in license copyright 2016-06-04 21:41:27 +01:00
mesos [SPARK-17648][CORE] TaskScheduler really needs offers to be an IndexedSeq 2016-09-29 15:36:40 -04:00
mllib [SPARK-14077][ML][FOLLOW-UP] Revert change for NB Model's Load to maintain compatibility with the model stored before 2.0 2016-09-30 08:18:48 -07:00
mllib-local [SPARK-17721][MLLIB][ML] Fix for multiplying transposed SparseMatrix with SparseVector 2016-09-29 15:39:57 -07:00
project [SPARK-17717][SQL] Add exist/find methods to Catalog. 2016-09-29 17:56:32 -07:00
python [SPARK-17699] Support for parsing JSON string columns 2016-09-29 13:01:10 -07:00
R [SPARK-17499][SPARKR][FOLLOWUP] Check null first for layers in spark.mlp to avoid warnings in test results 2016-09-27 21:19:59 -07:00
repl [SPARK-15487][WEB UI] Spark Master UI to reverse proxy Application and Workers UI 2016-09-08 17:20:20 -07:00
sbin [SPARK-17546][DEPLOY] start-* scripts should use hostname -f 2016-09-18 16:22:31 +01:00
sql [SPARK-17739][SQL] Collapse adjacent similar Window operators 2016-09-30 21:05:06 -07:00
streaming [SPARK-17638][STREAMING] Stop JVM StreamingContext when the Python process is dead 2016-09-22 14:26:45 -07:00
tools [SPARK-16535][BUILD] In pom.xml, remove groupId which is redundant definition and inherited from the parent 2016-07-19 11:59:46 +01:00
yarn [SPARK-16757] Set up Spark caller context to HDFS and YARN 2016-09-27 08:10:38 -05:00
.gitattributes [SPARK-3870] EOL character enforcement 2014-10-31 12:39:52 -07:00
.gitignore [MINOR][SPARKR] Add sparkr-vignettes.html to gitignore. 2016-09-24 01:03:11 -07:00
.travis.yml [SPARK-16967] move mesos to module 2016-08-26 12:25:22 -07:00
appveyor.yml [SPARK-17200][PROJECT INFRA][BUILD][SPARKR] Automate building and testing on Windows (currently SparkR only) 2016-09-08 08:26:59 -07:00
CONTRIBUTING.md [SPARK-17445][DOCS] Reference an ASF page as the main place to find third-party packages 2016-09-14 10:10:16 +01:00
LICENSE [SPARK-16781][PYSPARK] java launched by PySpark as gateway may not be the same java used in the spark environment 2016-08-24 20:04:09 +01:00
NOTICE [MINOR][BUILD] Add modernizr MIT license; specify "2014 and onwards" in license copyright 2016-06-04 21:41:27 +01:00
pom.xml [SPARK-17639][BUILD] Add jce.jar to buildclasspath when building. 2016-09-22 21:35:25 -07:00
README.md [SPARK-15821][DOCS] Include parallel build info 2016-06-14 13:59:01 +01:00
scalastyle-config.xml [SPARK-16877][BUILD] Add rules for preventing to use Java annotations (Deprecated and Override) 2016-08-04 21:43:05 +01:00

Apache Spark

Spark is a fast and general cluster computing system for Big Data. It provides high-level APIs in Scala, Java, Python, and R, and an optimized engine that supports general computation graphs for data analysis. It also supports a rich set of higher-level tools including Spark SQL for SQL and DataFrames, MLlib for machine learning, GraphX for graph processing, and Spark Streaming for stream processing.

http://spark.apache.org/

Online Documentation

You can find the latest Spark documentation, including a programming guide, on the project web page and project wiki. This README file only contains basic setup instructions.

Building Spark

Spark is built using Apache Maven. To build Spark and its example programs, run:

build/mvn -DskipTests clean package

(You do not need to do this if you downloaded a pre-built package.)

You can build Spark using more than one thread by using the -T option with Maven, see "Parallel builds in Maven 3". More detailed documentation is available from the project site, at "Building Spark". For developing Spark using an IDE, see Eclipse and IntelliJ.

Interactive Scala Shell

The easiest way to start using Spark is through the Scala shell:

./bin/spark-shell

Try the following command, which should return 1000:

scala> sc.parallelize(1 to 1000).count()

Interactive Python Shell

Alternatively, if you prefer Python, you can use the Python shell:

./bin/pyspark

And run the following command, which should also return 1000:

>>> sc.parallelize(range(1000)).count()

Example Programs

Spark also comes with several sample programs in the examples directory. To run one of them, use ./bin/run-example <class> [params]. For example:

./bin/run-example SparkPi

will run the Pi example locally.

You can set the MASTER environment variable when running examples to submit examples to a cluster. This can be a mesos:// or spark:// URL, "yarn" to run on YARN, and "local" to run locally with one thread, or "local[N]" to run locally with N threads. You can also use an abbreviated class name if the class is in the examples package. For instance:

MASTER=spark://host:7077 ./bin/run-example SparkPi

Many of the example programs print usage help if no params are given.

Running Tests

Testing first requires building Spark. Once Spark is built, tests can be run using:

./dev/run-tests

Please see the guidance on how to run tests for a module, or individual tests.

A Note About Hadoop Versions

Spark uses the Hadoop core library to talk to HDFS and other Hadoop-supported storage systems. Because the protocols have changed in different versions of Hadoop, you must build Spark against the same version that your cluster runs.

Please refer to the build documentation at "Specifying the Hadoop Version" for detailed guidance on building for a particular distribution of Hadoop, including building for particular Hive and Hive Thriftserver distributions.

Configuration

Please refer to the Configuration Guide in the online documentation for an overview on how to configure Spark.