Apache Spark - A unified analytics engine for large-scale data processing
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gatorsmile 1f06a5b6a0 [SPARK-17353][SPARK-16943][SPARK-16942][SQL] Fix multiple bugs in CREATE TABLE LIKE command
### What changes were proposed in this pull request?
The existing `CREATE TABLE LIKE` command has multiple issues:

- The generated table is non-empty when the source table is a data source table. The major reason is the data source table is using the table property `path` to store the location of table contents. Currently, we keep it unchanged. Thus, we still create the same table with the same location.

- The table type of the generated table is `EXTERNAL` when the source table is an external Hive Serde table. Currently, we explicitly set it to `MANAGED`, but Hive is checking the table property `EXTERNAL` to decide whether the table is `EXTERNAL` or not. (See https://github.com/apache/hive/blob/master/metastore/src/java/org/apache/hadoop/hive/metastore/ObjectStore.java#L1407-L1408) Thus, the created table is still `EXTERNAL`.

- When the source table is a `VIEW`, the metadata of the generated table contains the original view text and view original text. So far, this does not break anything, but it could cause something wrong in Hive. (For example, https://github.com/apache/hive/blob/master/metastore/src/java/org/apache/hadoop/hive/metastore/ObjectStore.java#L1405-L1406)

- The issue regarding the table `comment`. To follow what Hive does, the table comment should be cleaned, but the column comments should be still kept.

- The `INDEX` table is not supported. Thus, we should throw an exception in this case.

- `owner` should not be retained. `ToHiveTable` set it [here](e679bc3c1c/sql/hive/src/main/scala/org/apache/spark/sql/hive/client/HiveClientImpl.scala (L793)) no matter which value we set in `CatalogTable`. We set it to an empty string for avoiding the confusing output in Explain.

- Add a support for temp tables

- Like Hive, we should not copy the table properties from the source table to the created table, especially for the statistics-related properties, which could be wrong in the created table.

- `unsupportedFeatures` should not be copied from the source table. The created table does not have these unsupported features.

- When the type of source table is a view, the target table is using the default format of data source tables: `spark.sql.sources.default`.

This PR is to fix the above issues.

### How was this patch tested?
Improve the test coverage by adding more test cases

Author: gatorsmile <gatorsmile@gmail.com>

Closes #14531 from gatorsmile/createTableLike.
2016-09-01 16:36:14 +08:00
.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-17332][CORE] Make Java Loggers static members 2016-08-31 11:09:14 -07:00
conf [SPARK-13238][CORE] Add ganglia dmax parameter 2016-08-05 13:07:52 -07:00
core [SPARK-17332][CORE] Make Java Loggers static members 2016-08-31 11:09:14 -07:00
data [SPARK-16421][EXAMPLES][ML] Improve ML Example Outputs 2016-08-05 20:57:46 +01:00
dev [SPARK-17329][BUILD] Don't build PRs with -Pyarn unless YARN code changed 2016-09-01 09:10:01 +01:00
docs fixed typos 2016-09-01 09:32:05 +01:00
examples [SPARK-17001][ML] Enable standardScaler to standardize sparse vectors when withMean=True 2016-08-27 08:48:56 +01:00
external [SPARK-17229][SQL] PostgresDialect shouldn't widen float and short types during reads 2016-08-25 23:22:40 +02:00
graphx [SPARK-16779][TRIVIAL] Avoid using postfix operators where they do not add much and remove whitelisting 2016-08-08 15:54:03 -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-17316][TESTS] Fix MesosCoarseGrainedSchedulerBackendSuite 2016-08-31 15:25:13 -07:00
mllib [SPARK-17241][SPARKR][MLLIB] SparkR spark.glm should have configurable regularization parameter 2016-08-31 21:39:31 -07:00
mllib-local [ML][MLLIB] The require condition and message doesn't match in SparseMatrix. 2016-08-27 08:46:01 +01:00
project [SPARK-16967] move mesos to module 2016-08-26 12:25:22 -07:00
python [SPARK-17264][SQL] DataStreamWriter should document that it only supports Parquet for now 2016-08-30 11:19:45 +01:00
R [SPARK-17241][SPARKR][MLLIB] SparkR spark.glm should have configurable regularization parameter 2016-08-31 21:39:31 -07:00
repl [SPARK-17318][TESTS] Fix ReplSuite replicating blocks of object with class defined in repl again 2016-08-31 23:25:20 -07:00
sbin [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
sql [SPARK-17353][SPARK-16943][SPARK-16942][SQL] Fix multiple bugs in CREATE TABLE LIKE command 2016-09-01 16:36:14 +08:00
streaming [SPARK-17038][STREAMING] fix metrics retrieval source of 'lastReceivedBatch' 2016-08-17 16:31:42 -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-5682][CORE] Add encrypted shuffle in spark 2016-08-30 09:15:31 -07:00
.gitattributes [SPARK-3870] EOL character enforcement 2014-10-31 12:39:52 -07:00
.gitignore [SPARKR][BUILD] ignore cran-check.out under R folder 2016-08-25 12:11:27 -07:00
.travis.yml [SPARK-16967] move mesos to module 2016-08-26 12:25:22 -07:00
CONTRIBUTING.md [SPARK-6889] [DOCS] CONTRIBUTING.md updates to accompany contribution doc updates 2015-04-21 22:34:31 -07:00
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-5682][CORE] Add encrypted shuffle in spark 2016-08-30 09:15:31 -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.