## What changes were proposed in this pull request?
Follow-up for #17218, some minor fix for PySpark ```FPGrowth```.
## How was this patch tested?
Existing UT.
Author: Yanbo Liang <ybliang8@gmail.com>
Closes#18089 from yanboliang/spark-19281.
## What changes were proposed in this pull request?
Currently the whole block is fetched into memory(off heap by default) when shuffle-read. A block is defined by (shuffleId, mapId, reduceId). Thus it can be large when skew situations. If OOM happens during shuffle read, job will be killed and users will be notified to "Consider boosting spark.yarn.executor.memoryOverhead". Adjusting parameter and allocating more memory can resolve the OOM. However the approach is not perfectly suitable for production environment, especially for data warehouse.
Using Spark SQL as data engine in warehouse, users hope to have a unified parameter(e.g. memory) but less resource wasted(resource is allocated but not used). The hope is strong especially when migrating data engine to Spark from another one(e.g. Hive). Tuning the parameter for thousands of SQLs one by one is very time consuming.
It's not always easy to predict skew situations, when happen, it make sense to fetch remote blocks to disk for shuffle-read, rather than kill the job because of OOM.
In this pr, I propose to fetch big blocks to disk(which is also mentioned in SPARK-3019):
1. Track average size and also the outliers(which are larger than 2*avgSize) in MapStatus;
2. Request memory from `MemoryManager` before fetch blocks and release the memory to `MemoryManager` when `ManagedBuffer` is released.
3. Fetch remote blocks to disk when failing acquiring memory from `MemoryManager`, otherwise fetch to memory.
This is an improvement for memory control when shuffle blocks and help to avoid OOM in scenarios like below:
1. Single huge block;
2. Sizes of many blocks are underestimated in `MapStatus` and the actual footprint of blocks is much larger than the estimated.
## How was this patch tested?
Added unit test in `MapStatusSuite` and `ShuffleBlockFetcherIteratorSuite`.
Author: jinxing <jinxing6042@126.com>
Closes#16989 from jinxing64/SPARK-19659.
## What changes were proposed in this pull request?
Currently, when a task is calling spill() but it receives a killing request from driver (e.g., speculative task), the `TaskMemoryManager` will throw an `OOM` exception. And we don't catch `Fatal` exception when a error caused by `Thread.interrupt`. So for `ClosedByInterruptException`, we should throw `RuntimeException` instead of `OutOfMemoryError`.
https://issues.apache.org/jira/browse/SPARK-20250?jql=project%20%3D%20SPARK
## How was this patch tested?
Existing unit tests.
Author: Xianyang Liu <xianyang.liu@intel.com>
Closes#18090 from ConeyLiu/SPARK-20250.
## What changes were proposed in this pull request?
This is a follow-up to #18073. Taking a safer approach to shutdown the pool to prevent possible issue. Also using `ThreadUtils.newForkJoinPool` instead to set a better thread name.
## How was this patch tested?
Manually test.
Please review http://spark.apache.org/contributing.html before opening a pull request.
Author: Liang-Chi Hsieh <viirya@gmail.com>
Closes#18100 from viirya/SPARK-20848-followup.
## What changes were proposed in this pull request?
1. add instructions of 'cast' function When using 'show functions' and 'desc function cast'
command in spark-sql
2. Modify the instructions of functions，such as
boolean，tinyint，smallint，int，bigint，float，double，decimal，date，timestamp，binary，string
## How was this patch tested?
Before modification：
spark-sql>desc function boolean;
Function: boolean
Class: org.apache.spark.sql.catalyst.expressions.Cast
Usage: boolean(expr AS type) - Casts the value `expr` to the target data type `type`.
After modification：
spark-sql> desc function boolean;
Function: boolean
Class: org.apache.spark.sql.catalyst.expressions.Cast
Usage: boolean(expr) - Casts the value `expr` to the target data type `boolean`.
spark-sql> desc function cast
Function: cast
Class: org.apache.spark.sql.catalyst.expressions.Cast
Usage: cast(expr AS type) - Casts the value `expr` to the target data type `type`.
Author: liuxian <liu.xian3@zte.com.cn>
Closes#17698 from 10110346/wip_lx_0418.
## What changes were proposed in this pull request?
Follow-up to SPARK-16202:
1. Remove the duplication of the meaning of `SaveMode` (as one was in fact missing that had proven that the duplication may be incomplete in the future again)
2. Use standard scaladoc tags
/cc gatorsmile rxin yhuai (as they were involved previously)
## How was this patch tested?
local build
Author: Jacek Laskowski <jacek@japila.pl>
Closes#18026 from jaceklaskowski/CreatableRelationProvider-SPARK-16202.
## What changes were proposed in this pull request?
A one-liner change in `ShuffleExchange.nodeName` to cover the case when `coordinator` is `null`, so that the match expression is exhaustive.
Please refer to [SPARK-20872](https://issues.apache.org/jira/browse/SPARK-20872) for a description of the symptoms.
TL;DR is that inspecting a `ShuffleExchange` (directly or transitively) on the Executor side can hit a case where the `coordinator` field of a `ShuffleExchange` is null, and thus will trigger a `MatchError` in `ShuffleExchange.nodeName()`'s inexhaustive match expression.
Also changed two other match conditions in `ShuffleExchange` on the `coordinator` field to be consistent.
## How was this patch tested?
Manually tested this change with a case where the `coordinator` is null to make sure `ShuffleExchange.nodeName` doesn't throw a `MatchError` any more.
Author: Kris Mok <kris.mok@databricks.com>
Closes#18095 from rednaxelafx/shuffleexchange-nodename.
The DAGScheduler was sending a "stage submitted" event before it properly
updated the event's information. This meant that a listener (e.g. the
even logging listener) could record wrong information about the event.
This change sets the stage's submission time before the event is submitted,
when there are tasks to be executed in the stage.
Tested with existing unit tests.
Author: Marcelo Vanzin <vanzin@cloudera.com>
Closes#17925 from vanzin/SPARK-20205.
## What changes were proposed in this pull request?
This is a follow-up to SPARK-20857 to move the broadcast hint from Statistics into a new HintInfo class, so we can be more flexible in adding new hints in the future.
## How was this patch tested?
Updated test cases to reflect the change.
Author: Reynold Xin <rxin@databricks.com>
Closes#18087 from rxin/SPARK-20867.
## What changes were proposed in this pull request?
From JIRA: On each call to spark.read.parquet, a new ForkJoinPool is created. One of the threads in the pool is kept in the WAITING state, and never stopped, which leads to unbounded growth in number of threads.
We should shutdown the pool after reading parquet files.
## How was this patch tested?
Added a test to ParquetFileFormatSuite.
Please review http://spark.apache.org/contributing.html before opening a pull request.
Author: Liang-Chi Hsieh <viirya@gmail.com>
Closes#18073 from viirya/SPARK-20848.
## What changes were proposed in this pull request?
Fixed TypeError with python3 and numpy 1.12.1. Numpy's `reshape` no longer takes floats as arguments as of 1.12. Also, python3 uses float division for `/`, we should be using `//` to ensure that `_dataWithBiasSize` doesn't get set to a float.
## How was this patch tested?
Existing tests run using python3 and numpy 1.12.
Author: Bago Amirbekian <bago@databricks.com>
Closes#18081 from MrBago/BF-py3floatbug.
## What changes were proposed in this pull request?
- Fix incorrect tests for `_check_thresholds`.
- Move test to `ParamTests`.
## How was this patch tested?
Unit tests.
Author: zero323 <zero323@users.noreply.github.com>
Closes#18085 from zero323/SPARK-20631-FOLLOW-UP.
## What changes were proposed in this pull request?
Add test cases for PR-18062
## How was this patch tested?
The existing UT
Author: Peng <peng.meng@intel.com>
Closes#18068 from mpjlu/moreTest.
## What changes were proposed in this pull request?
When a TaskContext is not propagated properly to all child threads for the task, just like the reported cases in this issue, we fail to get to TID from TaskContext and that causes unable to release the lock and assertion failures. To resolve this, we have to explicitly pass the TID value to the `unlock` method.
## How was this patch tested?
Add new failing regression test case in `RDDSuite`.
Author: Xingbo Jiang <xingbo.jiang@databricks.com>
Closes#18076 from jiangxb1987/completion-iterator.
Changes:
pyspark.ml Estimators can take either a list of param maps or a dict of params. This change allows the CrossValidator and TrainValidationSplit Estimators to pass through lists of param maps to the underlying estimators so that those estimators can handle parallelization when appropriate (eg distributed hyper parameter tuning).
Testing:
Existing unit tests.
Author: Bago Amirbekian <bago@databricks.com>
Closes#18077 from MrBago/delegate_params.
The contribution is my original work and I license the work to the project under the project’s open source license.
Note: the Teradata JDBC connector limits the row size to 64K. The default string datatype equivalent I used is a 255 character/byte length varchar. This effectively limits the max number of string columns to 250 when using the Teradata jdbc connector.
## What changes were proposed in this pull request?
Added a teradataDialect for JDBC connection to Teradata. The Teradata dialect uses VARCHAR(255) in place of TEXT for string datatypes, and CHAR(1) in place of BIT(1) for boolean datatypes.
## How was this patch tested?
I added two unit tests to double check that the types get set correctly for a teradata jdbc url. I also ran a couple manual tests to make sure the jdbc connector worked with teradata and to make sure that an error was thrown if a row could potentially exceed 64K (this error comes from the teradata jdbc connector, not from the spark code). I did not check how string columns longer than 255 characters are handled.
Author: Kirby Linvill <kirby.linvill@teradata.com>
Author: klinvill <kjlinvill@gmail.com>
Closes#16746 from klinvill/master.
## What changes were proposed in this pull request?
This patch renames BroadcastHint to ResolvedHint (and Hint to UnresolvedHint) so the hint framework is more generic and would allow us to introduce other hint types in the future without introducing new hint nodes.
## How was this patch tested?
Updated test cases.
Author: Reynold Xin <rxin@databricks.com>
Closes#18072 from rxin/SPARK-20857.
## What changes were proposed in this pull request?
Joint coefficients with intercept for SparkR linear SVM summary.
## How was this patch tested?
Existing tests.
Author: Yanbo Liang <ybliang8@gmail.com>
Closes#18035 from yanboliang/svm-r.
## What changes were proposed in this pull request?
As srowen pointed in 609ba5f2b9 (commitcomment-22221259), the previous tests are not proper.
This follow-up is going to fix the tests.
## How was this patch tested?
Jenkins tests.
Please review http://spark.apache.org/contributing.html before opening a pull request.
Author: Liang-Chi Hsieh <viirya@gmail.com>
Closes#18048 from viirya/SPARK-20399-follow-up.
## What changes were proposed in this pull request?
This change skips tests that use the Hadoop libraries while running
on CRAN check with Windows as the operating system. This is to handle
cases where the Hadoop winutils binaries are missing on the target
system. The skipped tests consist of
1. Tests that save, load a model in MLlib
2. Tests that save, load CSV, JSON and Parquet files in SQL
3. Hive tests
## How was this patch tested?
Tested by running on a local windows VM with HADOOP_HOME unset. Also testing with https://win-builder.r-project.org
Author: Shivaram Venkataraman <shivaram@cs.berkeley.edu>
Closes#17966 from shivaram/sparkr-windows-cran.
## What changes were proposed in this pull request?
- Add a null check to RPackageUtils#checkManifestForR so that jars w/o manifests don't NPE.
## How was this patch tested?
- Unit tests and manual tests.
Author: James Shuster <jshuster@palantir.com>
Closes#18040 from jrshust/feature/r-package-utils.
### What changes were proposed in this pull request?
After we adding a new field `stats` into `CatalogTable`, we should not expose Hive-specific Stats metadata to `MetastoreRelation`. It complicates all the related codes. It also introduces a bug in `SHOW CREATE TABLE`. The statistics-related table properties should be skipped by `SHOW CREATE TABLE`, since it could be incorrect in the newly created table. See the Hive JIRA: https://issues.apache.org/jira/browse/HIVE-13792
Also fix the issue to fill Hive-generated RowCounts to our stats.
This PR is to handle Hive-specific Stats metadata in `HiveClientImpl`.
### How was this patch tested?
Added a few test cases.
Author: Xiao Li <gatorsmile@gmail.com>
Closes#14971 from gatorsmile/showCreateTableNew.
Restore code that was removed as part of SPARK-17979, but instead of
using the deprecated env variable name to propagate the class path, use
a new one.
Verified by running "./bin/spark-class o.a.s.executor.CoarseGrainedExecutorBackend"
manually.
Author: Marcelo Vanzin <vanzin@cloudera.com>
Closes#18037 from vanzin/SPARK-20814.
## What changes were proposed in this pull request?
support decision tree in R
## How was this patch tested?
added tests
Author: Zheng RuiFeng <ruifengz@foxmail.com>
Closes#17981 from zhengruifeng/dt_r.
and contains scala classes
## What changes were proposed in this pull request?
This change ensures that all references to guava from within the yarn shuffle jar pointed to the shaded guava class already provided in the jar.
Also, it explicitly excludes scala classes from being added to the jar.
## How was this patch tested?
Ran unit tests on the module and they passed.
javap now returns the expected result - reference to the shaded guava under `org/spark_project` (previously this was referring to `com.google...`
```
javap -cp common/network-yarn/target/scala-2.11/spark-2.3.0-SNAPSHOT-yarn-shuffle.jar -c org/apache/spark/network/yarn/YarnShuffleService | grep Lists
57: invokestatic #138 // Method org/spark_project/guava/collect/Lists.newArrayList:()Ljava/util/ArrayList;
```
Guava is still shaded in the jar:
```
jar -tf common/network-yarn/target/scala-2.11/spark-2.3.0-SNAPSHOT-yarn-shuffle.jar | grep guava | head
META-INF/maven/com.google.guava/
META-INF/maven/com.google.guava/guava/
META-INF/maven/com.google.guava/guava/pom.properties
META-INF/maven/com.google.guava/guava/pom.xml
org/spark_project/guava/
org/spark_project/guava/annotations/
org/spark_project/guava/annotations/Beta.class
org/spark_project/guava/annotations/GwtCompatible.class
org/spark_project/guava/annotations/GwtIncompatible.class
org/spark_project/guava/annotations/VisibleForTesting.class
```
(not sure if the above META-INF/* is a problem or not)
I took this jar, deployed it on a yarn cluster with shuffle service enabled, and made sure the YARN node managers came up. An application with a shuffle was run and it succeeded.
Author: Mark Grover <mark@apache.org>
Closes#17990 from markgrover/spark-20756.
## What changes were proposed in this pull request?
SPARK-20097 exposed degreesOfFreedom in LinearRegressionSummary and numInstances in GeneralizedLinearRegressionSummary. Python API should be updated to reflect these changes.
## How was this patch tested?
The existing UT
Author: Peng <peng.meng@intel.com>
Closes#18062 from mpjlu/spark-20764.
### What changes were proposed in this pull request?
Currently, we have a bug when we specify `IF NOT EXISTS` in `INSERT OVERWRITE` data source tables. For example, given a query:
```SQL
INSERT OVERWRITE TABLE $tableName partition (b=2, c=3) IF NOT EXISTS SELECT 9, 10
```
we will get the following error:
```
unresolved operator 'InsertIntoTable Relation[a#425,d#426,b#427,c#428] parquet, Map(b -> Some(2), c -> Some(3)), true, true;;
'InsertIntoTable Relation[a#425,d#426,b#427,c#428] parquet, Map(b -> Some(2), c -> Some(3)), true, true
+- Project [cast(9#423 as int) AS a#429, cast(10#424 as int) AS d#430]
+- Project [9 AS 9#423, 10 AS 10#424]
+- OneRowRelation$
```
This PR is to fix the issue to follow the behavior of Hive serde tables
> INSERT OVERWRITE will overwrite any existing data in the table or partition unless IF NOT EXISTS is provided for a partition
### How was this patch tested?
Modified an existing test case
Author: gatorsmile <gatorsmile@gmail.com>
Closes#18050 from gatorsmile/insertPartitionIfNotExists.
## What changes were proposed in this pull request?
Currently, when number of reduces is above 2000, HighlyCompressedMapStatus is used to store size of blocks. in HighlyCompressedMapStatus, only average size is stored for non empty blocks. Which is not good for memory control when we shuffle blocks. It makes sense to store the accurate size of block when it's above threshold.
## How was this patch tested?
Added test in MapStatusSuite.
Author: jinxing <jinxing6042@126.com>
Closes#18031 from jinxing64/SPARK-20801.
## What changes were proposed in this pull request?
On status column of the table, I removed the condition that forced only the display value to take on values Active, Blacklisted and Dead.
Before the removal, values used for sort and filter for that particular column was True and False.
## How was this patch tested?
Tested with Active, Blacklisted and Dead present as current status.
Author: John Lee <jlee2@yahoo-inc.com>
Closes#18036 from yoonlee95/SPARK-20813.
## What changes were proposed in this pull request?
This PR solution to run the SortShuffleSuite unit tests have residual spark_* system directory
For example:
OS:Windows 7
After the running SortShuffleSuite unit tests,
the system of TMP directory have '..\AppData\Local\Temp\spark-f64121f9-11b4-4ffd-a4f0-cfca66643503' not deleted
## How was this patch tested?
Run SortShuffleSuite unit test.
Author: caoxuewen <cao.xuewen@zte.com.cn>
Closes#17869 from heary-cao/SortShuffleSuite.
## What changes were proposed in this pull request?
Modified succeeded num in job detail page from "completed = stageData.completedIndices.size" to "completed = stageData.numCompleteTasks",which making succeeded tasks num in all jobs page and job detail page look more consistent, and more easily to find which stages the speculative task(s) were in.
## How was this patch tested?
manual tests
Author: fjh100456 <fu.jinhua6@zte.com.cn>
Closes#17923 from fjh100456/master.
Quick follow up to #17996 - forgot to add the HTML links to the relevant sections of the guide in the highlights list.
## How was this patch tested?
Built docs locally and tested links.
Author: Nick Pentreath <nickp@za.ibm.com>
Closes#18043 from MLnick/SPARK-20506-2.2-migration-guide-2.
## What changes were proposed in this pull request?
When two Breeze SparseMatrices are operated, the result matrix may contain provisional 0 values extra in rowIndices and data arrays. This causes an incoherence with the colPtrs data, but Breeze get away with this incoherence by keeping a counter of the valid data.
In spark, when this matrices are converted to SparseMatrices, Sparks relies solely on rowIndices, data, and colPtrs, but these might be incorrect because of breeze internal hacks. Therefore, we need to slice both rowIndices and data, using their counter of active data
This method is at least called by BlockMatrix when performing distributed block operations, causing exceptions on valid operations.
See http://stackoverflow.com/questions/33528555/error-thrown-when-using-blockmatrix-add
## How was this patch tested?
Added a test to MatricesSuite that verifies that the conversions are valid and that code doesn't crash. Originally the same code would crash on Spark.
Bugfix for https://issues.apache.org/jira/browse/SPARK-20687
Author: Ignacio Bermudez <ignaciobermudez@gmail.com>
Author: Ignacio Bermudez Corrales <icorrales@splunk.com>
Closes#17940 from ghoto/bug-fix/SPARK-20687.
## What changes were proposed in this pull request?
Replaced specific sequence encoders with generic sequence encoder to enable nesting of sequences.
Does not add support for nested arrays as that cannot be solved in this way.
## How was this patch tested?
```bash
build/mvn -DskipTests clean package && dev/run-tests
```
Additionally in Spark shell:
```
scala> Seq(Seq(Seq(1))).toDS.collect()
res0: Array[Seq[Seq[Int]]] = Array(List(List(1)))
```
Author: Michal Senkyr <mike.senkyr@gmail.com>
Closes#18011 from michalsenkyr/dataset-seq-nested.
## What changes were proposed in this pull request?
This PR improves the implementation of `ColumnStats` by using the following appoaches.
1. Declare subclasses of `ColumnStats` as `final`
2. Remove unnecessary call of `row.isNullAt(ordinal)`
3. Remove the dependency on `GenericInternalRow`
For 1., this declaration encourages method inlining and other optimizations of JIT compiler
For 2., in `gatherStats()`, while previous code in subclasses of `ColumnStats` always calls `row.isNullAt()` twice, the PR just calls `row.isNullAt()` only once.
For 3., `collectedStatistics()` returns `Array[Any]` instead of `GenericInternalRow`. This removes the dependency of unnecessary package and reduces the number of allocations of `GenericInternalRow`.
In addition to that, in the future, `gatherValueStats()`, which is specialized for each data type, can be effectively called from the generated code without using generic data structure `InternalRow`.
## How was this patch tested?
Tested by existing test suite
Author: Kazuaki Ishizaki <ishizaki@jp.ibm.com>
Closes#18002 from kiszk/SPARK-20770.
## What changes were proposed in this pull request?
spark-sql>SELECT ceil(1234567890123456);
1234567890123456
spark-sql>SELECT ceil(12345678901234567);
12345678901234568
spark-sql>SELECT ceil(123456789012345678);
123456789012345680
when the length of the getText is greater than 16. long to double will be precision loss.
but mysql handle the value is ok.
mysql> SELECT ceil(1234567890123456);
+------------------------+
| ceil(1234567890123456) |
+------------------------+
| 1234567890123456 |
+------------------------+
1 row in set (0.00 sec)
mysql> SELECT ceil(12345678901234567);
+-------------------------+
| ceil(12345678901234567) |
+-------------------------+
| 12345678901234567 |
+-------------------------+
1 row in set (0.00 sec)
mysql> SELECT ceil(123456789012345678);
+--------------------------+
| ceil(123456789012345678) |
+--------------------------+
| 123456789012345678 |
+--------------------------+
1 row in set (0.00 sec)
## How was this patch tested?
Supplement the unit test.
Author: caoxuewen <cao.xuewen@zte.com.cn>
Closes#18016 from heary-cao/ceil_long.
## What changes were proposed in this pull request?
PySpark StringIndexer supports StringOrderType added in #17879.
Author: Wayne Zhang <actuaryzhang@uber.com>
Closes#17978 from actuaryzhang/PythonStringIndexer.
## What changes were proposed in this pull request?
Currently, in the batch queries, timeout is disabled (i.e. GroupStateTimeout.NoTimeout) which means any GroupState.setTimeout*** operation would throw UnsupportedOperationException. This makes it weird when converting a streaming query into a batch query by changing the input DF from streaming to a batch DF. If the timeout was enabled and used, then the batch query will start throwing UnsupportedOperationException.
This PR creates the dummy state in batch queries with the provided timeoutConf so that it behaves in the same way. The code has been refactored to make it obvious when the state is being created for a batch query or a streaming query.
## How was this patch tested?
Additional tests
Author: Tathagata Das <tathagata.das1565@gmail.com>
Closes#18024 from tdas/SPARK-20792.
## What changes were proposed in this pull request?
Remove redundant check for libdir in CommandBuilderUtils
## How was this patch tested?
Existing tests
Author: Sean Owen <sowen@cloudera.com>
Closes#18032 from srowen/SPARK-20806.
Update ML guide for migration `2.1` -> `2.2` and the previous version migration guide section.
## How was this patch tested?
Build doc locally.
Author: Nick Pentreath <nickp@za.ibm.com>
Closes#17996 from MLnick/SPARK-20506-2.2-migration-guide.
## What changes were proposed in this pull request?
Some examples in the DataFrame methods are syntactically wrong, even though they are pseudo code. Fix these and some style issues.
Author: Wayne Zhang <actuaryzhang@uber.com>
Closes#18003 from actuaryzhang/sparkRDoc3.
## What changes were proposed in this pull request?
Rename `carsDF` to `df` in SparkR `rollup` and `cube` examples.
## How was this patch tested?
Manual tests.
Author: zero323 <zero323@users.noreply.github.com>
Closes#17988 from zero323/cube-docs.
## What changes were proposed in this pull request?
spark-sql>select month("1582-09-28");
spark-sql>10
For this case, the expected result is 9, but it is 10.
spark-sql>select day("1582-04-18");
spark-sql>28
For this case, the expected result is 18, but it is 28.
when the date before "1582-10-04", the function of `month` and `day` return the value which is not we expected.
## How was this patch tested?
unit tests
Author: liuxian <liu.xian3@zte.com.cn>
Closes#17997 from 10110346/wip_lx_0516.
## What changes were proposed in this pull request?
Add built-in SQL Function - COT.
## How was this patch tested?
unit tests
Author: Yuming Wang <wgyumg@gmail.com>
Closes#17999 from wangyum/SPARK-20751.
## What changes were proposed in this pull request?
This PR update to two:
1.adds the new unit tests.
testing would be performed when there is no shuffle stage,
shuffle will not generate the data file and the index files.
2.Modify the '[SPARK-4085] rerun map stage if reduce stage cannot find its local shuffle file' unit test,
parallelize is 1 but not is 2, Check the index file and delete.
## How was this patch tested?
The new unit test.
Author: caoxuewen <cao.xuewen@zte.com.cn>
Closes#17868 from heary-cao/ShuffleSuite.
Fix quadratic List indexing in ParquetWriteSupport.
I noticed this function while profiling some code with today. It showed up as a significant factor in a table with twenty columns; with hundreds of columns, it could dominate any other function call.
## What changes were proposed in this pull request?
The writeFields method iterates from 0 until number of fields, indexing into rootFieldWriters for each element. rootFieldWriters is a List, so indexing is a linear operation. The complexity of the writeFields method is thus quadratic in the number of fields.
Solution: explicitly convert rootFieldWriters to Array (implicitly converted to WrappedArray) for constant-time indexing.
## How was this patch tested?
This is a one-line change for performance reasons.
Author: tpoterba <tpoterba@broadinstitute.org>
Author: Tim Poterba <tpoterba@gmail.com>
Closes#18005 from tpoterba/tpoterba-patch-1.
## What changes were proposed in this pull request?
GenerateUnsafeProjection.writeStructToBuffer() did not honor the assumption that the caller must make sure that a value is not null before using the getter. This could lead to various errors. This change fixes that behavior.
Example of code generated before:
```scala
/* 059 */ final UTF8String fieldName = value.getUTF8String(0);
/* 060 */ if (value.isNullAt(0)) {
/* 061 */ rowWriter1.setNullAt(0);
/* 062 */ } else {
/* 063 */ rowWriter1.write(0, fieldName);
/* 064 */ }
```
Example of code generated now:
```scala
/* 060 */ boolean isNull1 = value.isNullAt(0);
/* 061 */ UTF8String value1 = isNull1 ? null : value.getUTF8String(0);
/* 062 */ if (isNull1) {
/* 063 */ rowWriter1.setNullAt(0);
/* 064 */ } else {
/* 065 */ rowWriter1.write(0, value1);
/* 066 */ }
```
## How was this patch tested?
Adds GenerateUnsafeProjectionSuite.
Author: Ala Luszczak <ala@databricks.com>
Closes#18030 from ala/fix-generate-unsafe-projection.
