Apache Spark - A unified analytics engine for large-scale data processing
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Robert (Bobby) Evans fac469e2e0 [SPARK-28774][SQL] Fix exchange reuse for columnar data
### What changes were proposed in this pull request?
The rule ReuseExchange optimization rule will look for instances of Exchange that have the same plan and convert dedupe them to them to a ReuseExchangeExec instance. In the current Spark codebase all Exchange instances are row based, but if we use the spark.sql.extensions config to put in our own columnar based exchange implementation reuse will throw an exception saying that there was a columnar mismatch.

### Why are the changes needed?
Without it Reused Columnar Exchanges throw an exception

### Does this PR introduce any user-facing change?
No

### How was this patch tested?

I tested this patch by running it against a query that was showing this exact issue and it fixed it.

I also added a very simple unit test that shows the issue.

Closes #25499 from revans2/reused-columnar-exchange.

Authored-by: Robert (Bobby) Evans <bobby@apache.org>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
2019-08-21 18:10:26 +08:00
.github [SPARK-28578][INFRA] Improve Github pull request template 2019-08-16 09:45:15 +09:00
assembly [SPARK-27300][GRAPH] Add Spark Graph modules and dependencies 2019-06-09 00:26:26 -07:00
bin [SPARK-28525][DEPLOY] Allow Launcher to be applied Java options 2019-07-30 12:45:32 -07:00
build [SPARK-27979][BUILD][test-maven] Remove deprecated --force option in build/mvn and run-tests.py 2019-06-10 18:40:46 -07:00
common [MINOR] Fix typos in comments and replace an explicit type with <> 2019-08-10 16:47:11 -05:00
conf [SPARK-28475][CORE] Add regex MetricFilter to GraphiteSink 2019-08-02 17:50:15 +08:00
core [SPARK-27937][CORE] Revert partial logic for auto namespace discovery 2019-08-20 12:42:35 -07:00
data [SPARK-22666][ML][SQL] Spark datasource for image format 2018-09-05 11:59:00 -07:00
dev [SPARK-28737][CORE] Update Jersey to 2.29 2019-08-16 15:08:04 -07:00
docs [SPARK-28541][WEBUI] Document Storage page 2019-08-20 20:05:13 -05:00
examples [MINOR] Fix typos in comments and replace an explicit type with <> 2019-08-10 16:47:11 -05:00
external [SPARK-28744][SQL][TEST] rename SharedSQLContext to SharedSparkSession 2019-08-19 19:01:56 +08:00
graph [SPARK-27300][GRAPH] Add Spark Graph modules and dependencies 2019-06-09 00:26:26 -07:00
graphx [SPARK-27682][CORE][GRAPHX][MLLIB] Replace use of collections and methods that will be removed in Scala 2.13 with work-alikes 2019-05-15 09:29:12 -05:00
hadoop-cloud [SPARK-23977][SQL] Support High Performance S3A committers [test-hadoop3.2] 2019-08-15 09:39:26 -07:00
launcher [MINOR] Fix typos in comments and replace an explicit type with <> 2019-08-10 16:47:11 -05:00
licenses [SPARK-27557][DOC] Add copy button to Python API docs for easier copying of code-blocks 2019-05-01 11:26:18 -05:00
licenses-binary [SPARK-28737][CORE] Update Jersey to 2.29 2019-08-16 15:08:04 -07:00
mllib [SPARK-28434][TESTS][ML] Fix values in dummy tree in DecisionTreeSuite 2019-08-19 17:01:14 -05:00
mllib-local [SPARK-28421][ML] SparseVector.apply performance optimization 2019-07-23 20:20:22 -05:00
project Revert "[SPARK-28527][SQL][TEST] Re-run all the tests in SQLQueryTestSuite via Thrift Server" 2019-08-18 16:54:24 -07:00
python [SPARK-28777][PYTHON][DOCS] Fix format_string doc string with the correct parameters 2019-08-19 20:44:46 -07:00
R [SPARK-28756][R][FOLLOW-UP] Specify minimum and maximum Java versions 2019-08-19 20:15:17 +09:00
repl [SPARK-28601][CORE][SQL] Use StandardCharsets.UTF_8 instead of "UTF-8" string representation, and get rid of UnsupportedEncodingException 2019-08-05 20:45:54 -07:00
resource-managers [SPARK-28634][YARN] Ignore kerberos login config in client mode AM 2019-08-19 11:06:02 -07:00
sbin [SPARK-28164] Fix usage description of start-slave.sh 2019-06-26 12:42:33 -05:00
sql [SPARK-28774][SQL] Fix exchange reuse for columnar data 2019-08-21 18:10:26 +08:00
streaming [MINOR] Fix typos in comments and replace an explicit type with <> 2019-08-10 16:47:11 -05:00
tools [SPARK-25956] Make Scala 2.12 as default Scala version in Spark 3.0 2018-11-14 16:22:23 -08:00
.gitattributes [SPARK-3870] EOL character enforcement 2014-10-31 12:39:52 -07:00
.gitignore [SPARK-27371][CORE] Support GPU-aware resources scheduling in Standalone 2019-08-09 07:49:03 -05:00
appveyor.yml [MINOR] Fix typos in comments and replace an explicit type with <> 2019-08-10 16:47:11 -05:00
CONTRIBUTING.md [MINOR][DOCS] Tighten up some key links to the project and download pages to use HTTPS 2019-05-21 10:56:42 -07:00
LICENSE [SPARK-27557][DOC] Add copy button to Python API docs for easier copying of code-blocks 2019-05-01 11:26:18 -05:00
LICENSE-binary [SPARK-28737][CORE] Update Jersey to 2.29 2019-08-16 15:08:04 -07:00
NOTICE [SPARK-23654][BUILD] remove jets3t as a dependency of spark 2018-08-16 12:34:23 -07:00
NOTICE-binary [SPARK-27862][BUILD] Move to json4s 3.6.6 2019-05-30 19:42:56 -05:00
pom.xml Revert "[SPARK-28759][BUILD] Upgrade scala-maven-plugin to 4.1.1" 2019-08-19 20:32:07 +09:00
README.md [SPARK-28473][DOC] Stylistic consistency of build command in README 2019-07-23 16:29:46 -07:00
scalastyle-config.xml [SPARK-25986][BUILD] Add rules to ban throw Errors in application code 2018-11-14 13:05:18 -08:00

Apache Spark

Spark is a unified analytics engine for large-scale data processing. 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 Structured Streaming for stream processing.

https://spark.apache.org/

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Online Documentation

You can find the latest Spark documentation, including a programming guide, on the project web page. 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 general development tips, including info on developing Spark using an IDE, see "Useful Developer Tools".

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 1,000,000,000:

scala> spark.range(1000 * 1000 * 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 1,000,000,000:

>>> spark.range(1000 * 1000 * 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.

There is also a Kubernetes integration test, see resource-managers/kubernetes/integration-tests/README.md

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 and Enabling YARN" 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.

Contributing

Please review the Contribution to Spark guide for information on how to get started contributing to the project.