spark-instrumented-optimizer/python
Jungtaek Lim 8d4d433191 [SPARK-33836][SS][PYTHON] Expose DataStreamReader.table and DataStreamWriter.toTable
### What changes were proposed in this pull request?

This PR proposes to expose `DataStreamReader.table` (SPARK-32885) and `DataStreamWriter.toTable` (SPARK-32896) to PySpark, which are the only way to read and write with table in Structured Streaming.

### Why are the changes needed?

Please refer SPARK-32885 and SPARK-32896 for rationalizations of these public APIs. This PR only exposes them to PySpark.

### Does this PR introduce _any_ user-facing change?

Yes, PySpark users will be able to read and write with table in Structured Streaming query.

### How was this patch tested?

Manually tested.

> v1 table

>> create table A and ingest to the table A

```
spark.sql("""
create table table_pyspark_parquet (
    value long,
    `timestamp` timestamp
) USING parquet
""")
df = spark.readStream.format('rate').option('rowsPerSecond', 100).load()
query = df.writeStream.toTable('table_pyspark_parquet', checkpointLocation='/tmp/checkpoint5')
query.lastProgress
query.stop()
```

>> read table A and ingest to the table B which doesn't exist

```
df2 = spark.readStream.table('table_pyspark_parquet')
query2 = df2.writeStream.toTable('table_pyspark_parquet_nonexist', format='parquet', checkpointLocation='/tmp/checkpoint2')
query2.lastProgress
query2.stop()
```

>> select tables

```
spark.sql("DESCRIBE TABLE table_pyspark_parquet").show()
spark.sql("SELECT * FROM table_pyspark_parquet").show()

spark.sql("DESCRIBE TABLE table_pyspark_parquet_nonexist").show()
spark.sql("SELECT * FROM table_pyspark_parquet_nonexist").show()
```

> v2 table (leveraging Apache Iceberg as it provides V2 table and custom catalog as well)

>> create table A and ingest to the table A

```
spark.sql("""
create table iceberg_catalog.default.table_pyspark_v2table (
    value long,
    `timestamp` timestamp
) USING iceberg
""")
df = spark.readStream.format('rate').option('rowsPerSecond', 100).load()
query = df.select('value', 'timestamp').writeStream.toTable('iceberg_catalog.default.table_pyspark_v2table', checkpointLocation='/tmp/checkpoint_v2table_1')
query.lastProgress
query.stop()
```

>> ingest to the non-exist table B

```
df2 = spark.readStream.format('rate').option('rowsPerSecond', 100).load()
query2 = df2.select('value', 'timestamp').writeStream.toTable('iceberg_catalog.default.table_pyspark_v2table_nonexist', checkpointLocation='/tmp/checkpoint_v2table_2')
query2.lastProgress
query2.stop()
```

>> ingest to the non-exist table C partitioned by `value % 10`

```
df3 = spark.readStream.format('rate').option('rowsPerSecond', 100).load()
df3a = df3.selectExpr('value', 'timestamp', 'value % 10 AS partition').repartition('partition')
query3 = df3a.writeStream.partitionBy('partition').toTable('iceberg_catalog.default.table_pyspark_v2table_nonexist_partitioned', checkpointLocation='/tmp/checkpoint_v2table_3')
query3.lastProgress
query3.stop()
```

>> select tables

```
spark.sql("DESCRIBE TABLE iceberg_catalog.default.table_pyspark_v2table").show()
spark.sql("SELECT * FROM iceberg_catalog.default.table_pyspark_v2table").show()

spark.sql("DESCRIBE TABLE iceberg_catalog.default.table_pyspark_v2table_nonexist").show()
spark.sql("SELECT * FROM iceberg_catalog.default.table_pyspark_v2table_nonexist").show()

spark.sql("DESCRIBE TABLE iceberg_catalog.default.table_pyspark_v2table_nonexist_partitioned").show()
spark.sql("SELECT * FROM iceberg_catalog.default.table_pyspark_v2table_nonexist_partitioned").show()
```

Closes #30835 from HeartSaVioR/SPARK-33836.

Lead-authored-by: Jungtaek Lim <kabhwan.opensource@gmail.com>
Co-authored-by: Jungtaek Lim (HeartSaVioR) <kabhwan.opensource@gmail.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
2020-12-21 19:42:59 +09:00
..
docs [SPARK-33824][PYTHON][DOCS] Restructure and improve Python package management page 2020-12-18 10:03:07 +09:00
lib [SPARK-30884][PYSPARK] Upgrade to Py4J 0.10.9 2020-02-20 09:09:30 -08:00
pyspark [SPARK-33836][SS][PYTHON] Expose DataStreamReader.table and DataStreamWriter.toTable 2020-12-21 19:42:59 +09:00
test_coverage [SPARK-7721][PYTHON][TESTS] Adds PySpark coverage generation script 2018-01-22 22:12:50 +09:00
test_support Spelling r common dev mlib external project streaming resource managers python 2020-11-27 10:22:45 -06:00
.coveragerc [SPARK-7721][PYTHON][TESTS] Adds PySpark coverage generation script 2018-01-22 22:12:50 +09:00
.gitignore [SPARK-3946] gitignore in /python includes wrong directory 2014-10-14 14:09:39 -07:00
MANIFEST.in [SPARK-32714][PYTHON] Initial pyspark-stubs port 2020-09-24 14:15:36 +09:00
mypy.ini [SPARK-32320][PYSPARK] Remove mutable default arguments 2020-12-08 09:35:36 +08:00
pylintrc [SPARK-32435][PYTHON] Remove heapq3 port from Python 3 2020-07-27 20:10:13 +09:00
README.md [SPARK-30884][PYSPARK] Upgrade to Py4J 0.10.9 2020-02-20 09:09:30 -08:00
run-tests [SPARK-29672][PYSPARK] update spark testing framework to use python3 2019-11-14 10:18:55 -08:00
run-tests-with-coverage [SPARK-26252][PYTHON] Add support to run specific unittests and/or doctests in python/run-tests script 2018-12-05 15:22:08 +08:00
run-tests.py [SPARK-33565][BUILD][PYTHON] remove python3.8 and fix breakage 2020-11-25 15:15:50 -08:00
setup.cfg [SPARK-1267][SPARK-18129] Allow PySpark to be pip installed 2016-11-16 14:22:15 -08:00
setup.py [SPARK-33371][PYTHON] Update setup.py and tests for Python 3.9 2020-11-06 15:05:37 -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/

Online Documentation

You can find the latest Spark documentation, including a programming guide, on the project web page

Python Packaging

This README file only contains basic information related to pip installed PySpark. This packaging is currently experimental and may change in future versions (although we will do our best to keep compatibility). Using PySpark requires the Spark JARs, and if you are building this from source please see the builder instructions at "Building Spark".

The Python packaging for Spark is not intended to replace all of the other use cases. This Python packaged version of Spark is suitable for interacting with an existing cluster (be it Spark standalone, YARN, or Mesos) - but does not contain the tools required to set up your own standalone Spark cluster. You can download the full version of Spark from the Apache Spark downloads page.

NOTE: If you are using this with a Spark standalone cluster you must ensure that the version (including minor version) matches or you may experience odd errors.

Python Requirements

At its core PySpark depends on Py4J, but some additional sub-packages have their own extra requirements for some features (including numpy, pandas, and pyarrow).