Apache Spark - A unified analytics engine for large-scale data processing
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Marco Gaido cd10f9df82 [SPARK-23916][SQL] Add array_join function
## What changes were proposed in this pull request?

The PR adds the SQL function `array_join`. The behavior of the function is based on Presto's one.

The function accepts an `array` of `string` which is to be joined, a `string` which is the delimiter to use between the items of the first argument and optionally a `string` which is used to replace `null` values.

## How was this patch tested?

added UTs

Author: Marco Gaido <marcogaido91@gmail.com>

Closes #21011 from mgaido91/SPARK-23916.
2018-04-26 13:37:13 +09:00
.github [SPARK-18073][DOCS][WIP] Migrate wiki to spark.apache.org web site 2016-11-23 11:25:47 +00:00
assembly [SPARK-23807][BUILD] Add Hadoop 3.1 profile with relevant POM fix ups 2018-04-24 09:57:09 -07:00
bin [SPARK-22839][K8S] Remove the use of init-container for downloading remote dependencies 2018-03-19 11:29:56 -07:00
build [SPARK-19810][BUILD][CORE] Remove support for Scala 2.10 2017-07-13 17:06:24 +08:00
common [SPARK-24029][CORE] Follow up: set SO_REUSEADDR on the server socket. 2018-04-24 09:10:29 +08:00
conf [SPARK-22466][SPARK SUBMIT] export SPARK_CONF_DIR while conf is default 2017-11-09 14:33:08 +09:00
core [SPARK-23807][BUILD] Add Hadoop 3.1 profile with relevant POM fix ups 2018-04-24 09:57:09 -07:00
data [SPARK-23205][ML] Update ImageSchema.readImages to correctly set alpha values for four-channel images 2018-01-25 18:15:29 -06:00
dev [SPARK-23807][BUILD] Add Hadoop 3.1 profile with relevant POM fix ups 2018-04-24 09:57:09 -07:00
docs [SPARK-22683][CORE] Add a executorAllocationRatio parameter to throttle the parallelism of the dynamic allocation 2018-04-24 10:56:55 -05:00
examples [SPARK-22968][DSTREAM] Throw an exception on partition revoking issue 2018-04-17 21:08:42 -05:00
external [SPARK-24050][SS] Calculate input / processing rates correctly for DataSourceV2 streaming sources 2018-04-25 12:21:55 -07:00
graphx [SPARK-23028] Bump master branch version to 2.4.0-SNAPSHOT 2018-01-13 00:37:59 +08:00
hadoop-cloud [SPARK-23807][BUILD] Add Hadoop 3.1 profile with relevant POM fix ups 2018-04-24 09:57:09 -07:00
launcher [SPARK-22941][CORE] Do not exit JVM when submit fails with in-process launcher. 2018-04-11 10:13:44 -05:00
licenses [SPARK-19112][CORE] Support for ZStandard codec 2017-11-01 14:54:08 +01:00
mllib [SPARK-23990][ML] Instruments logging improvements - ML regression package 2018-04-24 11:02:22 -07:00
mllib-local [SPARK-23085][ML] API parity for mllib.linalg.Vectors.sparse 2018-01-19 09:28:35 -06:00
project [SPARK-23455][ML] Default Params in ML should be saved separately in metadata 2018-04-24 10:40:25 -07:00
python [SPARK-23916][SQL] Add array_join function 2018-04-26 13:37:13 +09:00
R [SPARK-24069][R] Add array_min / array_max functions 2018-04-26 09:12:38 +08:00
repl [SPARK-23538][CORE] Remove custom configuration for SSL client. 2018-03-05 15:03:27 -08:00
resource-managers [SPARK-23956][YARN] Use effective RPC port in AM registration 2018-04-16 12:01:42 +08:00
sbin [SPARK-22994][K8S] Use a single image for all Spark containers. 2018-01-11 10:37:35 -08:00
sql [SPARK-23916][SQL] Add array_join function 2018-04-26 13:37:13 +09:00
streaming [SPARK-23361][YARN] Allow AM to restart after initial tokens expire. 2018-03-23 13:59:21 +08:00
tools [SPARK-23028] Bump master branch version to 2.4.0-SNAPSHOT 2018-01-13 00:37:59 +08:00
.gitattributes [SPARK-3870] EOL character enforcement 2014-10-31 12:39:52 -07:00
.gitignore [SPARK-23572][DOCS] Bring "security.md" up to date. 2018-03-26 12:45:45 -07:00
.travis.yml [SPARK-18278][SCHEDULER] Spark on Kubernetes - Basic Scheduler Backend 2017-11-28 23:02:09 -08:00
appveyor.yml [SPARK-22817][R] Use fixed testthat version for SparkR tests in AppVeyor 2017-12-17 14:40:41 +09:00
CONTRIBUTING.md [SPARK-18073][DOCS][WIP] Migrate wiki to spark.apache.org web site 2016-11-23 11:25:47 +00:00
LICENSE [SPARK-19112][CORE] Support for ZStandard codec 2017-11-01 14:54:08 +01:00
NOTICE [SPARK-18278][SCHEDULER] Spark on Kubernetes - Basic Scheduler Backend 2017-11-28 23:02:09 -08:00
pom.xml [SPARK-23807][BUILD] Add Hadoop 3.1 profile with relevant POM fix ups 2018-04-24 09:57:09 -07:00
README.md [MINOR][DOCS] Replace non-breaking space to normal spaces that breaks rendering markdown 2017-04-03 10:09:11 +01:00
scalastyle-config.xml [SPARK-23550][CORE] Cleanup Utils. 2018-03-07 13:42:06 -08:00

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. 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 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.

Contributing

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