## What changes were proposed in this pull request?
Currently we check pandas version by capturing if `ImportError` for the specific imports is raised or not but we can compare `LooseVersion` of the version strings as the same as we're checking pyarrow version.
## How was this patch tested?
Existing tests.
Author: Takuya UESHIN <ueshin@databricks.com>
Closes#20054 from ueshin/issues/SPARK-22874.
## What changes were proposed in this pull request?
Upgrade Spark to Arrow 0.8.0 for Java and Python. Also includes an upgrade of Netty to 4.1.17 to resolve dependency requirements.
The highlights that pertain to Spark for the update from Arrow versoin 0.4.1 to 0.8.0 include:
* Java refactoring for more simple API
* Java reduced heap usage and streamlined hot code paths
* Type support for DecimalType, ArrayType
* Improved type casting support in Python
* Simplified type checking in Python
## How was this patch tested?
Existing tests
Author: Bryan Cutler <cutlerb@gmail.com>
Author: Shixiong Zhu <zsxwing@gmail.com>
Closes#19884 from BryanCutler/arrow-upgrade-080-SPARK-22324.
## What changes were proposed in this pull request?
This change adds local checkpoint support to datasets and respective bind from Python Dataframe API.
If reliability requirements can be lowered to favor performance, as in cases of further quick transformations followed by a reliable save, localCheckpoints() fit very well.
Furthermore, at the moment Reliable checkpoints still incur double computation (see #9428)
In general it makes the API more complete as well.
## How was this patch tested?
Python land quick use case:
```python
>>> from time import sleep
>>> from pyspark.sql import types as T
>>> from pyspark.sql import functions as F
>>> def f(x):
sleep(1)
return x*2
...:
>>> df1 = spark.range(30, numPartitions=6)
>>> df2 = df1.select(F.udf(f, T.LongType())("id"))
>>> %time _ = df2.collect()
CPU times: user 7.79 ms, sys: 5.84 ms, total: 13.6 ms
Wall time: 12.2 s
>>> %time df3 = df2.localCheckpoint()
CPU times: user 2.38 ms, sys: 2.3 ms, total: 4.68 ms
Wall time: 10.3 s
>>> %time _ = df3.collect()
CPU times: user 5.09 ms, sys: 410 µs, total: 5.5 ms
Wall time: 148 ms
>>> sc.setCheckpointDir(".")
>>> %time df3 = df2.checkpoint()
CPU times: user 4.04 ms, sys: 1.63 ms, total: 5.67 ms
Wall time: 20.3 s
```
Author: Fernando Pereira <fernando.pereira@epfl.ch>
Closes#19805 from ferdonline/feature_dataset_localCheckpoint.
## What changes were proposed in this pull request?
When converting Pandas DataFrame/Series from/to Spark DataFrame using `toPandas()` or pandas udfs, timestamp values behave to respect Python system timezone instead of session timezone.
For example, let's say we use `"America/Los_Angeles"` as session timezone and have a timestamp value `"1970-01-01 00:00:01"` in the timezone. Btw, I'm in Japan so Python timezone would be `"Asia/Tokyo"`.
The timestamp value from current `toPandas()` will be the following:
```
>>> spark.conf.set("spark.sql.session.timeZone", "America/Los_Angeles")
>>> df = spark.createDataFrame([28801], "long").selectExpr("timestamp(value) as ts")
>>> df.show()
+-------------------+
| ts|
+-------------------+
|1970-01-01 00:00:01|
+-------------------+
>>> df.toPandas()
ts
0 1970-01-01 17:00:01
```
As you can see, the value becomes `"1970-01-01 17:00:01"` because it respects Python timezone.
As we discussed in #18664, we consider this behavior is a bug and the value should be `"1970-01-01 00:00:01"`.
## How was this patch tested?
Added tests and existing tests.
Author: Takuya UESHIN <ueshin@databricks.com>
Closes#19607 from ueshin/issues/SPARK-22395.
## What changes were proposed in this pull request?
Adding date and timestamp support with Arrow for `toPandas()` and `pandas_udf`s. Timestamps are stored in Arrow as UTC and manifested to the user as timezone-naive localized to the Python system timezone.
## How was this patch tested?
Added Scala tests for date and timestamp types under ArrowConverters, ArrowUtils, and ArrowWriter suites. Added Python tests for `toPandas()` and `pandas_udf`s with date and timestamp types.
Author: Bryan Cutler <cutlerb@gmail.com>
Author: Takuya UESHIN <ueshin@databricks.com>
Closes#18664 from BryanCutler/arrow-date-timestamp-SPARK-21375.
## What changes were proposed in this pull request?
This PR proposes to mark the existing warnings as `DeprecationWarning` and print out warnings for deprecated functions.
This could be actually useful for Spark app developers. I use (old) PyCharm and this IDE can detect this specific `DeprecationWarning` in some cases:
**Before**
<img src="https://user-images.githubusercontent.com/6477701/31762664-df68d9f8-b4f6-11e7-8773-f0468f70a2cc.png" height="45" />
**After**
<img src="https://user-images.githubusercontent.com/6477701/31762662-de4d6868-b4f6-11e7-98dc-3c8446a0c28a.png" height="70" />
For console usage, `DeprecationWarning` is usually disabled (see https://docs.python.org/2/library/warnings.html#warning-categories and https://docs.python.org/3/library/warnings.html#warning-categories):
```
>>> import warnings
>>> filter(lambda f: f[2] == DeprecationWarning, warnings.filters)
[('ignore', <_sre.SRE_Pattern object at 0x10ba58c00>, <type 'exceptions.DeprecationWarning'>, <_sre.SRE_Pattern object at 0x10bb04138>, 0), ('ignore', None, <type 'exceptions.DeprecationWarning'>, None, 0)]
```
so, it won't actually mess up the terminal much unless it is intended.
If this is intendedly enabled, it'd should as below:
```
>>> import warnings
>>> warnings.simplefilter('always', DeprecationWarning)
>>>
>>> from pyspark.sql import functions
>>> functions.approxCountDistinct("a")
.../spark/python/pyspark/sql/functions.py:232: DeprecationWarning: Deprecated in 2.1, use approx_count_distinct instead.
"Deprecated in 2.1, use approx_count_distinct instead.", DeprecationWarning)
...
```
These instances were found by:
```
cd python/pyspark
grep -r "Deprecated" .
grep -r "deprecated" .
grep -r "deprecate" .
```
## How was this patch tested?
Manually tested.
Author: hyukjinkwon <gurwls223@gmail.com>
Closes#19535 from HyukjinKwon/deprecated-warning.
## What changes were proposed in this pull request?
Currently percentile_approx never returns the first element when percentile is in (relativeError, 1/N], where relativeError default 1/10000, and N is the total number of elements. But ideally, percentiles in [0, 1/N] should all return the first element as the answer.
For example, given input data 1 to 10, if a user queries 10% (or even less) percentile, it should return 1, because the first value 1 already reaches 10%. Currently it returns 2.
Based on the paper, targetError is not rounded up, and searching index should start from 0 instead of 1. By following the paper, we should be able to fix the cases mentioned above.
## How was this patch tested?
Added a new test case and fix existing test cases.
Author: Zhenhua Wang <wzh_zju@163.com>
Closes#19438 from wzhfy/improve_percentile_approx.
## What changes were proposed in this pull request?
This PR adds an apply() function on df.groupby(). apply() takes a pandas udf that is a transformation on `pandas.DataFrame` -> `pandas.DataFrame`.
Static schema
-------------------
```
schema = df.schema
pandas_udf(schema)
def normalize(df):
df = df.assign(v1 = (df.v1 - df.v1.mean()) / df.v1.std()
return df
df.groupBy('id').apply(normalize)
```
Dynamic schema
-----------------------
**This use case is removed from the PR and we will discuss this as a follow up. See discussion https://github.com/apache/spark/pull/18732#pullrequestreview-66583248**
Another example to use pd.DataFrame dtypes as output schema of the udf:
```
sample_df = df.filter(df.id == 1).toPandas()
def foo(df):
ret = # Some transformation on the input pd.DataFrame
return ret
foo_udf = pandas_udf(foo, foo(sample_df).dtypes)
df.groupBy('id').apply(foo_udf)
```
In interactive use case, user usually have a sample pd.DataFrame to test function `foo` in their notebook. Having been able to use `foo(sample_df).dtypes` frees user from specifying the output schema of `foo`.
Design doc: https://github.com/icexelloss/spark/blob/pandas-udf-doc/docs/pyspark-pandas-udf.md
## How was this patch tested?
* Added GroupbyApplyTest
Author: Li Jin <ice.xelloss@gmail.com>
Author: Takuya UESHIN <ueshin@databricks.com>
Author: Bryan Cutler <cutlerb@gmail.com>
Closes#18732 from icexelloss/groupby-apply-SPARK-20396.
## What changes were proposed in this pull request?
This is a follow-up of #19384.
In the previous pr, only definitions of the config names were modified, but we also need to modify the names in runtime or tests specified as string literal.
## How was this patch tested?
Existing tests but modified the config names.
Author: Takuya UESHIN <ueshin@databricks.com>
Closes#19462 from ueshin/issues/SPARK-22159/fup1.
## What changes were proposed in this pull request?
The `percentile_approx` function previously accepted numeric type input and output double type results.
But since all numeric types, date and timestamp types are represented as numerics internally, `percentile_approx` can support them easily.
After this PR, it supports date type, timestamp type and numeric types as input types. The result type is also changed to be the same as the input type, which is more reasonable for percentiles.
This change is also required when we generate equi-height histograms for these types.
## How was this patch tested?
Added a new test and modified some existing tests.
Author: Zhenhua Wang <wangzhenhua@huawei.com>
Closes#19321 from wzhfy/approx_percentile_support_types.
## What changes were proposed in this pull request?
When calling `DataFrame.toPandas()` (without Arrow enabled), if there is a `IntegralType` column (`IntegerType`, `ShortType`, `ByteType`) that has null values the following exception is thrown:
ValueError: Cannot convert non-finite values (NA or inf) to integer
This is because the null values first get converted to float NaN during the construction of the Pandas DataFrame in `from_records`, and then it is attempted to be converted back to to an integer where it fails.
The fix is going to check if the Pandas DataFrame can cause such failure when converting, if so, we don't do the conversion and use the inferred type by Pandas.
Closes#18945
## How was this patch tested?
Added pyspark test.
Author: Liang-Chi Hsieh <viirya@gmail.com>
Closes#19319 from viirya/SPARK-21766.
## What changes were proposed in this pull request?
Correct DataFrame doc.
## How was this patch tested?
Only doc change, no tests.
Author: Yanbo Liang <ybliang8@gmail.com>
Closes#19173 from yanboliang/df-doc.
## What changes were proposed in this pull request?
This PR proposes to support unicodes in Param methods in ML, other missed functions in DataFrame.
For example, this causes a `ValueError` in Python 2.x when param is a unicode string:
```python
>>> from pyspark.ml.classification import LogisticRegression
>>> lr = LogisticRegression()
>>> lr.hasParam("threshold")
True
>>> lr.hasParam(u"threshold")
Traceback (most recent call last):
...
raise TypeError("hasParam(): paramName must be a string")
TypeError: hasParam(): paramName must be a string
```
This PR is based on https://github.com/apache/spark/pull/13036
## How was this patch tested?
Unit tests in `python/pyspark/ml/tests.py` and `python/pyspark/sql/tests.py`.
Author: hyukjinkwon <gurwls223@gmail.com>
Author: sethah <seth.hendrickson16@gmail.com>
Closes#17096 from HyukjinKwon/SPARK-15243.
## What changes were proposed in this pull request?
This PR proposes to add a wrapper for `unionByName` API to R and Python as well.
**Python**
```python
df1 = spark.createDataFrame([[1, 2, 3]], ["col0", "col1", "col2"])
df2 = spark.createDataFrame([[4, 5, 6]], ["col1", "col2", "col0"])
df1.unionByName(df2).show()
```
```
+----+----+----+
|col0|col1|col3|
+----+----+----+
| 1| 2| 3|
| 6| 4| 5|
+----+----+----+
```
**R**
```R
df1 <- select(createDataFrame(mtcars), "carb", "am", "gear")
df2 <- select(createDataFrame(mtcars), "am", "gear", "carb")
head(unionByName(limit(df1, 2), limit(df2, 2)))
```
```
carb am gear
1 4 1 4
2 4 1 4
3 4 1 4
4 4 1 4
```
## How was this patch tested?
Doctests for Python and unit test added in `test_sparkSQL.R` for R.
Author: hyukjinkwon <gurwls223@gmail.com>
Closes#19105 from HyukjinKwon/unionByName-r-python.
## What changes were proposed in this pull request?
This PR make `DataFrame.sample(...)` can omit `withReplacement` defaulting `False`, consistently with equivalent Scala / Java API.
In short, the following examples are allowed:
```python
>>> df = spark.range(10)
>>> df.sample(0.5).count()
7
>>> df.sample(fraction=0.5).count()
3
>>> df.sample(0.5, seed=42).count()
5
>>> df.sample(fraction=0.5, seed=42).count()
5
```
In addition, this PR also adds some type checking logics as below:
```python
>>> df = spark.range(10)
>>> df.sample().count()
...
TypeError: withReplacement (optional), fraction (required) and seed (optional) should be a bool, float and number; however, got [].
>>> df.sample(True).count()
...
TypeError: withReplacement (optional), fraction (required) and seed (optional) should be a bool, float and number; however, got [<type 'bool'>].
>>> df.sample(42).count()
...
TypeError: withReplacement (optional), fraction (required) and seed (optional) should be a bool, float and number; however, got [<type 'int'>].
>>> df.sample(fraction=False, seed="a").count()
...
TypeError: withReplacement (optional), fraction (required) and seed (optional) should be a bool, float and number; however, got [<type 'bool'>, <type 'str'>].
>>> df.sample(seed=[1]).count()
...
TypeError: withReplacement (optional), fraction (required) and seed (optional) should be a bool, float and number; however, got [<type 'list'>].
>>> df.sample(withReplacement="a", fraction=0.5, seed=1)
...
TypeError: withReplacement (optional), fraction (required) and seed (optional) should be a bool, float and number; however, got [<type 'str'>, <type 'float'>, <type 'int'>].
```
## How was this patch tested?
Manually tested, unit tests added in doc tests and manually checked the built documentation for Python.
Author: hyukjinkwon <gurwls223@gmail.com>
Closes#18999 from HyukjinKwon/SPARK-21779.
## What changes were proposed in this pull request?
Adds the recently added `summary` method to the python dataframe interface.
## How was this patch tested?
Additional inline doctests.
Author: Andrew Ray <ray.andrew@gmail.com>
Closes#18762 from aray/summary-py.
## What changes were proposed in this pull request?
JIRA issue: https://issues.apache.org/jira/browse/SPARK-21658
Add default None for value in `na.replace` since `Dataframe.replace` and `DataframeNaFunctions.replace` are alias.
The default values are the same now.
```
>>> df = sqlContext.createDataFrame([('Alice', 10, 80.0)])
>>> df.replace({"Alice": "a"}).first()
Row(_1=u'a', _2=10, _3=80.0)
>>> df.na.replace({"Alice": "a"}).first()
Row(_1=u'a', _2=10, _3=80.0)
```
## How was this patch tested?
Existing tests.
cc viirya
Author: byakuinss <grace.chinhanyu@gmail.com>
Closes#18895 from byakuinss/SPARK-21658.
## What changes were proposed in this pull request?
Currently `df.na.replace("*", Map[String, String]("NULL" -> null))` will produce exception.
This PR enables passing null/None as value in the replacement map in DataFrame.replace().
Note that the replacement map keys and values should still be the same type, while the values can have a mix of null/None and that type.
This PR enables following operations for example:
`df.na.replace("*", Map[String, String]("NULL" -> null))`(scala)
`df.na.replace("*", Map[Any, Any](60 -> null, 70 -> 80))`(scala)
`df.na.replace('Alice', None)`(python)
`df.na.replace([10, 20])`(python, replacing with None is by default)
One use case could be: I want to replace all the empty strings with null/None because they were incorrectly generated and then drop all null/None data
`df.na.replace("*", Map("" -> null)).na.drop()`(scala)
`df.replace(u'', None).dropna()`(python)
## How was this patch tested?
Scala unit test.
Python doctest and unit test.
Author: bravo-zhang <mzhang1230@gmail.com>
Closes#18820 from bravo-zhang/spark-14932.
## What changes were proposed in this pull request?
Integrate Apache Arrow with Spark to increase performance of `DataFrame.toPandas`. This has been done by using Arrow to convert data partitions on the executor JVM to Arrow payload byte arrays where they are then served to the Python process. The Python DataFrame can then collect the Arrow payloads where they are combined and converted to a Pandas DataFrame. Data types except complex, date, timestamp, and decimal are currently supported, otherwise an `UnsupportedOperation` exception is thrown.
Additions to Spark include a Scala package private method `Dataset.toArrowPayload` that will convert data partitions in the executor JVM to `ArrowPayload`s as byte arrays so they can be easily served. A package private class/object `ArrowConverters` that provide data type mappings and conversion routines. In Python, a private method `DataFrame._collectAsArrow` is added to collect Arrow payloads and a SQLConf "spark.sql.execution.arrow.enable" can be used in `toPandas()` to enable using Arrow (uses the old conversion by default).
## How was this patch tested?
Added a new test suite `ArrowConvertersSuite` that will run tests on conversion of Datasets to Arrow payloads for supported types. The suite will generate a Dataset and matching Arrow JSON data, then the dataset is converted to an Arrow payload and finally validated against the JSON data. This will ensure that the schema and data has been converted correctly.
Added PySpark tests to verify the `toPandas` method is producing equal DataFrames with and without pyarrow. A roundtrip test to ensure the pandas DataFrame produced by pyspark is equal to a one made directly with pandas.
Author: Bryan Cutler <cutlerb@gmail.com>
Author: Li Jin <ice.xelloss@gmail.com>
Author: Li Jin <li.jin@twosigma.com>
Author: Wes McKinney <wes.mckinney@twosigma.com>
Closes#18459 from BryanCutler/toPandas_with_arrow-SPARK-13534.
## What changes were proposed in this pull request?
Currently, it throws a NPE when missing columns but join type is speicified in join at PySpark as below:
```python
spark.conf.set("spark.sql.crossJoin.enabled", "false")
spark.range(1).join(spark.range(1), how="inner").show()
```
```
Traceback (most recent call last):
...
py4j.protocol.Py4JJavaError: An error occurred while calling o66.join.
: java.lang.NullPointerException
at org.apache.spark.sql.Dataset.join(Dataset.scala:931)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
...
```
```python
spark.conf.set("spark.sql.crossJoin.enabled", "true")
spark.range(1).join(spark.range(1), how="inner").show()
```
```
...
py4j.protocol.Py4JJavaError: An error occurred while calling o84.join.
: java.lang.NullPointerException
at org.apache.spark.sql.Dataset.join(Dataset.scala:931)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
...
```
This PR suggests to follow Scala's one as below:
```scala
scala> spark.conf.set("spark.sql.crossJoin.enabled", "false")
scala> spark.range(1).join(spark.range(1), Seq.empty[String], "inner").show()
```
```
org.apache.spark.sql.AnalysisException: Detected cartesian product for INNER join between logical plans
Range (0, 1, step=1, splits=Some(8))
and
Range (0, 1, step=1, splits=Some(8))
Join condition is missing or trivial.
Use the CROSS JOIN syntax to allow cartesian products between these relations.;
...
```
```scala
scala> spark.conf.set("spark.sql.crossJoin.enabled", "true")
scala> spark.range(1).join(spark.range(1), Seq.empty[String], "inner").show()
```
```
+---+---+
| id| id|
+---+---+
| 0| 0|
+---+---+
```
**After**
```python
spark.conf.set("spark.sql.crossJoin.enabled", "false")
spark.range(1).join(spark.range(1), how="inner").show()
```
```
Traceback (most recent call last):
...
pyspark.sql.utils.AnalysisException: u'Detected cartesian product for INNER join between logical plans\nRange (0, 1, step=1, splits=Some(8))\nand\nRange (0, 1, step=1, splits=Some(8))\nJoin condition is missing or trivial.\nUse the CROSS JOIN syntax to allow cartesian products between these relations.;'
```
```python
spark.conf.set("spark.sql.crossJoin.enabled", "true")
spark.range(1).join(spark.range(1), how="inner").show()
```
```
+---+---+
| id| id|
+---+---+
| 0| 0|
+---+---+
```
## How was this patch tested?
Added tests in `python/pyspark/sql/tests.py`.
Author: hyukjinkwon <gurwls223@gmail.com>
Closes#18484 from HyukjinKwon/SPARK-21264.
## What changes were proposed in this pull request?
Integrate Apache Arrow with Spark to increase performance of `DataFrame.toPandas`. This has been done by using Arrow to convert data partitions on the executor JVM to Arrow payload byte arrays where they are then served to the Python process. The Python DataFrame can then collect the Arrow payloads where they are combined and converted to a Pandas DataFrame. All non-complex data types are currently supported, otherwise an `UnsupportedOperation` exception is thrown.
Additions to Spark include a Scala package private method `Dataset.toArrowPayloadBytes` that will convert data partitions in the executor JVM to `ArrowPayload`s as byte arrays so they can be easily served. A package private class/object `ArrowConverters` that provide data type mappings and conversion routines. In Python, a public method `DataFrame.collectAsArrow` is added to collect Arrow payloads and an optional flag in `toPandas(useArrow=False)` to enable using Arrow (uses the old conversion by default).
## How was this patch tested?
Added a new test suite `ArrowConvertersSuite` that will run tests on conversion of Datasets to Arrow payloads for supported types. The suite will generate a Dataset and matching Arrow JSON data, then the dataset is converted to an Arrow payload and finally validated against the JSON data. This will ensure that the schema and data has been converted correctly.
Added PySpark tests to verify the `toPandas` method is producing equal DataFrames with and without pyarrow. A roundtrip test to ensure the pandas DataFrame produced by pyspark is equal to a one made directly with pandas.
Author: Bryan Cutler <cutlerb@gmail.com>
Author: Li Jin <ice.xelloss@gmail.com>
Author: Li Jin <li.jin@twosigma.com>
Author: Wes McKinney <wes.mckinney@twosigma.com>
Closes#15821 from BryanCutler/wip-toPandas_with_arrow-SPARK-13534.
## What changes were proposed in this pull request?
Currently we convert a spark DataFrame to Pandas Dataframe by `pd.DataFrame.from_records`. It infers the data type from the data and doesn't respect the spark DataFrame Schema. This PR fixes it.
## How was this patch tested?
a new regression test
Author: hyukjinkwon <gurwls223@gmail.com>
Author: Wenchen Fan <wenchen@databricks.com>
Author: Wenchen Fan <cloud0fan@gmail.com>
Closes#18378 from cloud-fan/to_pandas.
## What changes were proposed in this pull request?
Document Dataset.union is resolution by position, not by name, since this has been a confusing point for a lot of users.
## How was this patch tested?
N/A - doc only change.
Author: Reynold Xin <rxin@databricks.com>
Closes#18256 from rxin/SPARK-21042.
## What changes were proposed in this pull request?
Allow fill/replace of NAs with booleans, both in Python and Scala
## How was this patch tested?
Unit tests, doctests
This PR is original work from me and I license this work to the Spark project
Author: Ruben Berenguel Montoro <ruben@mostlymaths.net>
Author: Ruben Berenguel <ruben@mostlymaths.net>
Closes#18164 from rberenguel/SPARK-19732-fillna-bools.
### What changes were proposed in this pull request?
This PR does the following tasks:
- Added since
- Added the Python API
- Added test cases
### How was this patch tested?
Added test cases to both Scala and Python
Author: gatorsmile <gatorsmile@gmail.com>
Closes#18147 from gatorsmile/createOrReplaceGlobalTempView.
Now that Structured Streaming has been out for several Spark release and has large production use cases, the `Experimental` label is no longer appropriate. I've left `InterfaceStability.Evolving` however, as I think we may make a few changes to the pluggable Source & Sink API in Spark 2.3.
Author: Michael Armbrust <michael@databricks.com>
Closes#18065 from marmbrus/streamingGA.
## What changes were proposed in this pull request?
Adds `hint` method to PySpark `DataFrame`.
## How was this patch tested?
Unit tests, doctests.
Author: zero323 <zero323@users.noreply.github.com>
Closes#17850 from zero323/SPARK-20584.
## What changes were proposed in this pull request?
Currently pyspark Dataframe.fillna API supports boolean type when we pass dict, but it is missing in documentation.
## How was this patch tested?
>>> spark.createDataFrame([Row(a=True),Row(a=None)]).fillna({"a" : True}).show()
+----+
| a|
+----+
|true|
|true|
+----+
Please review http://spark.apache.org/contributing.html before opening a pull request.
Author: Srinivasa Reddy Vundela <vsr@cloudera.com>
Closes#17688 from vundela/fillna_doc_fix.
## What changes were proposed in this pull request?
- Allows skipping `value` argument if `to_replace` is a `dict`:
```python
df = sc.parallelize([("Alice", 1, 3.0)]).toDF()
df.replace({"Alice": "Bob"}).show()
````
- Adds validation step to ensure homogeneous values / replacements.
- Simplifies internal control flow.
- Improves unit tests coverage.
## How was this patch tested?
Existing unit tests, additional unit tests, manual testing.
Author: zero323 <zero323@users.noreply.github.com>
Closes#16793 from zero323/SPARK-19454.
## What changes were proposed in this pull request?
Update docs for NaN handling in approxQuantile.
## How was this patch tested?
existing tests.
Author: Zheng RuiFeng <ruifengz@foxmail.com>
Closes#17369 from zhengruifeng/doc_quantiles_nan.
## What changes were proposed in this pull request?
This PR adds a special streaming deduplication operator to support `dropDuplicates` with `aggregation` and watermark. It reuses the `dropDuplicates` API but creates new logical plan `Deduplication` and new physical plan `DeduplicationExec`.
The following cases are supported:
- one or multiple `dropDuplicates()` without aggregation (with or without watermark)
- `dropDuplicates` before aggregation
Not supported cases:
- `dropDuplicates` after aggregation
Breaking changes:
- `dropDuplicates` without aggregation doesn't work with `complete` or `update` mode.
## How was this patch tested?
The new unit tests.
Author: Shixiong Zhu <shixiong@databricks.com>
Closes#16970 from zsxwing/dedup.
## What changes were proposed in this pull request?
Add coalesce on DataFrame for down partitioning without shuffle and coalesce on Column
## How was this patch tested?
manual, unit tests
Author: Felix Cheung <felixcheung_m@hotmail.com>
Closes#16739 from felixcheung/rcoalesce.
## What changes were proposed in this pull request?
- Provides correct description of the semantics of a `dict` argument passed as `to_replace`.
- Describes type requirements for collection arguments.
- Describes behavior with `to_replace: List[T]` and `value: T`
## How was this patch tested?
Manual testing, documentation build.
Author: zero323 <zero323@users.noreply.github.com>
Closes#16792 from zero323/SPARK-19453.
## What changes were proposed in this pull request?
1, add the multi-cols support based on current private api
2, add the multi-cols support to pyspark
## How was this patch tested?
unit tests
Author: Zheng RuiFeng <ruifengz@foxmail.com>
Author: Ruifeng Zheng <ruifengz@foxmail.com>
Closes#12135 from zhengruifeng/quantile4multicols.
## What changes were proposed in this pull request?
- [X] Make sure all join types are clearly mentioned
- [X] Make join labeling/style consistent
- [X] Make join label ordering docs the same
- [X] Improve join documentation according to above for Scala
- [X] Improve join documentation according to above for Python
- [X] Improve join documentation according to above for R
## How was this patch tested?
No tests b/c docs.
Please review http://spark.apache.org/contributing.html before opening a pull request.
Author: anabranch <wac.chambers@gmail.com>
Closes#16504 from anabranch/SPARK-19126.
## What changes were proposed in this pull request?
This PR adds two of the newly added methods of `Dataset`s to Python:
`withWatermark` and `checkpoint`
## How was this patch tested?
Doc tests
Author: Burak Yavuz <brkyvz@gmail.com>
Closes#15921 from brkyvz/py-watermark.
## What changes were proposed in this pull request?
I found the documentation for the sample method to be confusing, this adds more clarification across all languages.
- [x] Scala
- [x] Python
- [x] R
- [x] RDD Scala
- [ ] RDD Python with SEED
- [X] RDD Java
- [x] RDD Java with SEED
- [x] RDD Python
## How was this patch tested?
NA
Please review https://cwiki.apache.org/confluence/display/SPARK/Contributing+to+Spark before opening a pull request.
Author: anabranch <wac.chambers@gmail.com>
Author: Bill Chambers <bill@databricks.com>
Closes#15815 from anabranch/SPARK-18365.
## What changes were proposed in this pull request?
Add a crossJoin function to the DataFrame API similar to that in Scala. Joins with no condition (cartesian products) must be specified with the crossJoin API
## How was this patch tested?
Added python tests to ensure that an AnalysisException if a cartesian product is specified without crossJoin(), and that cartesian products can execute if specified via crossJoin()
(Please explain how this patch was tested. E.g. unit tests, integration tests, manual tests)
(If this patch involves UI changes, please attach a screenshot; otherwise, remove this)
Please review https://cwiki.apache.org/confluence/display/SPARK/Contributing+to+Spark before opening a pull request.
Author: Srinath Shankar <srinath@databricks.com>
Closes#15493 from srinathshankar/crosspython.
[SPARK-11905](https://issues.apache.org/jira/browse/SPARK-11905) added support for `persist`/`cache` for `Dataset`. However, there is no user-facing API to check if a `Dataset` is cached and if so what the storage level is. This PR adds `getStorageLevel` to `Dataset`, analogous to `RDD.getStorageLevel`.
Updated `DatasetCacheSuite`.
Author: Nick Pentreath <nickp@za.ibm.com>
Closes#13780 from MLnick/ds-storagelevel.
Signed-off-by: Michael Armbrust <michael@databricks.com>
## What changes were proposed in this pull request?
In PySpark, the invalid join type will not throw error for the following join:
```df1.join(df2, how='not-a-valid-join-type')```
The signature of the join is:
```def join(self, other, on=None, how=None):```
The existing code completely ignores the `how` parameter when `on` is `None`. This patch will process the arguments passed to join and pass in to JVM Spark SQL Analyzer, which will validate the join type passed.
## How was this patch tested?
Used manual and existing test suites.
Author: Bijay Pathak <bkpathak@mtu.edu>
Closes#15409 from bkpathak/SPARK-14761.
## What changes were proposed in this pull request?
Global temporary view is a cross-session temporary view, which means it's shared among all sessions. Its lifetime is the lifetime of the Spark application, i.e. it will be automatically dropped when the application terminates. It's tied to a system preserved database `global_temp`(configurable via SparkConf), and we must use the qualified name to refer a global temp view, e.g. SELECT * FROM global_temp.view1.
changes for `SessionCatalog`:
1. add a new field `gloabalTempViews: GlobalTempViewManager`, to access the shared global temp views, and the global temp db name.
2. `createDatabase` will fail if users wanna create `global_temp`, which is system preserved.
3. `setCurrentDatabase` will fail if users wanna set `global_temp`, which is system preserved.
4. add `createGlobalTempView`, which is used in `CreateViewCommand` to create global temp views.
5. add `dropGlobalTempView`, which is used in `CatalogImpl` to drop global temp view.
6. add `alterTempViewDefinition`, which is used in `AlterViewAsCommand` to update the view definition for local/global temp views.
7. `renameTable`/`dropTable`/`isTemporaryTable`/`lookupRelation`/`getTempViewOrPermanentTableMetadata`/`refreshTable` will handle global temp views.
changes for SQL commands:
1. `CreateViewCommand`/`AlterViewAsCommand` is updated to support global temp views
2. `ShowTablesCommand` outputs a new column `database`, which is used to distinguish global and local temp views.
3. other commands can also handle global temp views if they call `SessionCatalog` APIs which accepts global temp views, e.g. `DropTableCommand`, `AlterTableRenameCommand`, `ShowColumnsCommand`, etc.
changes for other public API
1. add a new method `dropGlobalTempView` in `Catalog`
2. `Catalog.findTable` can find global temp view
3. add a new method `createGlobalTempView` in `Dataset`
## How was this patch tested?
new tests in `SQLViewSuite`
Author: Wenchen Fan <wenchen@databricks.com>
Closes#14897 from cloud-fan/global-temp-view.
## What changes were proposed in this pull request?
In PySpark, `df.take(1)` runs a single-stage job which computes only one partition of the DataFrame, while `df.limit(1).collect()` computes all partitions and runs a two-stage job. This difference in performance is confusing.
The reason why `limit(1).collect()` is so much slower is that `collect()` internally maps to `df.rdd.<some-pyspark-conversions>.toLocalIterator`, which causes Spark SQL to build a query where a global limit appears in the middle of the plan; this, in turn, ends up being executed inefficiently because limits in the middle of plans are now implemented by repartitioning to a single task rather than by running a `take()` job on the driver (this was done in #7334, a patch which was a prerequisite to allowing partition-local limits to be pushed beneath unions, etc.).
In order to fix this performance problem I think that we should generalize the fix from SPARK-10731 / #8876 so that `DataFrame.collect()` also delegates to the Scala implementation and shares the same performance properties. This patch modifies `DataFrame.collect()` to first collect all results to the driver and then pass them to Python, allowing this query to be planned using Spark's `CollectLimit` optimizations.
## How was this patch tested?
Added a regression test in `sql/tests.py` which asserts that the expected number of jobs, stages, and tasks are run for both queries.
Author: Josh Rosen <joshrosen@databricks.com>
Closes#15068 from JoshRosen/pyspark-collect-limit.
## What changes were proposed in this pull request?
Require the use of CROSS join syntax in SQL (and a new crossJoin
DataFrame API) to specify explicit cartesian products between relations.
By cartesian product we mean a join between relations R and S where
there is no join condition involving columns from both R and S.
If a cartesian product is detected in the absence of an explicit CROSS
join, an error must be thrown. Turning on the
"spark.sql.crossJoin.enabled" configuration flag will disable this check
and allow cartesian products without an explicit CROSS join.
The new crossJoin DataFrame API must be used to specify explicit cross
joins. The existing join(DataFrame) method will produce a INNER join
that will require a subsequent join condition.
That is df1.join(df2) is equivalent to select * from df1, df2.
## How was this patch tested?
Added cross-join.sql to the SQLQueryTestSuite to test the check for cartesian products. Added a couple of tests to the DataFrameJoinSuite to test the crossJoin API. Modified various other test suites to explicitly specify a cross join where an INNER join or a comma-separated list was previously used.
Author: Srinath Shankar <srinath@databricks.com>
Closes#14866 from srinathshankar/crossjoin.
## What changes were proposed in this pull request?
`withColumnRenamed` and `drop` is a no-op if the given column name does not exists. Python documentation also describe that, but this PR adds more explicit line consistently with Scala to reduce the ambiguity.
## How was this patch tested?
It's about docs.
Author: Dongjoon Hyun <dongjoon@apache.org>
Closes#14288 from dongjoon-hyun/SPARK-16651.
## What changes were proposed in this pull request?
doc change only
## How was this patch tested?
doc change only
Author: Mortada Mehyar <mortada.mehyar@gmail.com>
Closes#14253 from mortada/histogram_typos.
