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4235 commits

Author SHA1 Message Date
Herman van Hovell c2a1576c23 [SPARK-17335][SQL] Fix ArrayType and MapType CatalogString.
## What changes were proposed in this pull request?
the `catalogString` for `ArrayType` and `MapType` currently calls the `simpleString` method on its children. This is a problem when the child is a struct, the `struct.simpleString` implementation truncates the number of fields it shows (25 at max). This breaks the generation of a proper `catalogString`, and has shown to cause errors while writing to Hive.

This PR fixes this by providing proper `catalogString` implementations for `ArrayData` or `MapData`.

## How was this patch tested?
Added testing for `catalogString` to `DataTypeSuite`.

Author: Herman van Hovell <hvanhovell@databricks.com>

Closes #14938 from hvanhovell/SPARK-17335.
2016-09-03 19:02:20 +02:00
Sandeep Singh a8a35b39b9 [MINOR][SQL] Not dropping all necessary tables
## What changes were proposed in this pull request?
was not dropping table `parquet_t3`

## How was this patch tested?
tested `LogicalPlanToSQLSuite` locally

Author: Sandeep Singh <sandeep@techaddict.me>

Closes #13767 from techaddict/minor-8.
2016-09-03 15:35:19 +01:00
Srinath Shankar e6132a6cf1 [SPARK-17298][SQL] Require explicit CROSS join for cartesian products
## 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.
2016-09-03 00:20:43 +02:00
Sameer Agarwal a2c9acb0e5 [SPARK-16334] Reusing same dictionary column for decoding consecutive row groups shouldn't throw an error
## What changes were proposed in this pull request?

This patch fixes a bug in the vectorized parquet reader that's caused by re-using the same dictionary column vector while reading consecutive row groups. Specifically, this issue manifests for a certain distribution of dictionary/plain encoded data while we read/populate the underlying bit packed dictionary data into a column-vector based data structure.

## How was this patch tested?

Manually tested on datasets provided by the community. Thanks to Chris Perluss and Keith Kraus for their invaluable help in tracking down this issue!

Author: Sameer Agarwal <sameerag@cs.berkeley.edu>

Closes #14941 from sameeragarwal/parquet-exception-2.
2016-09-02 15:16:16 -07:00
Davies Liu ed9c884dcf [SPARK-17230] [SQL] Should not pass optimized query into QueryExecution in DataFrameWriter
## What changes were proposed in this pull request?

Some analyzer rules have assumptions on logical plans, optimizer may break these assumption, we should not pass an optimized query plan into QueryExecution (will be analyzed again), otherwise we may some weird bugs.

For example, we have a rule for decimal calculation to promote the precision before binary operations, use PromotePrecision as placeholder to indicate that this rule should not apply twice. But a Optimizer rule will remove this placeholder, that break the assumption, then the rule applied twice, cause wrong result.

Ideally, we should make all the analyzer rules all idempotent, that may require lots of effort to double checking them one by one (may be not easy).

An easier approach could be never feed a optimized plan into Analyzer, this PR fix the case for RunnableComand, they will be optimized, during execution, the passed `query` will also be passed into QueryExecution again. This PR make these `query` not part of the children, so they will not be optimized and analyzed again.

Right now, we did not know a logical plan is optimized or not, we could introduce a flag for that, and make sure a optimized logical plan will not be analyzed again.

## How was this patch tested?

Added regression tests.

Author: Davies Liu <davies@databricks.com>

Closes #14797 from davies/fix_writer.
2016-09-02 15:10:12 -07:00
Josh Rosen 6bcbf9b743 [SPARK-17351] Refactor JDBCRDD to expose ResultSet -> Seq[Row] utility methods
This patch refactors the internals of the JDBC data source in order to allow some of its code to be re-used in an automated comparison testing harness. Here are the key changes:

- Move the JDBC `ResultSetMetadata` to `StructType` conversion logic from `JDBCRDD.resolveTable()` to the `JdbcUtils` object (as a new `getSchema(ResultSet, JdbcDialect)` method), allowing it to be applied on `ResultSet`s that are created elsewhere.
- Move the `ResultSet` to `InternalRow` conversion methods from `JDBCRDD` to `JdbcUtils`:
  - It makes sense to move the `JDBCValueGetter` type and `makeGetter` functions here given that their write-path counterparts (`JDBCValueSetter`) are already in `JdbcUtils`.
  - Add an internal `resultSetToSparkInternalRows` method which takes a `ResultSet` and schema and returns an `Iterator[InternalRow]`. This effectively extracts the main loop of `JDBCRDD` into its own method.
  - Add a public `resultSetToRows` method to `JdbcUtils`, which wraps the minimal machinery around `resultSetToSparkInternalRows` in order to allow it to be called from outside of a Spark job.
- Make `JdbcDialect.get` into a `DeveloperApi` (`JdbcDialect` itself is already a `DeveloperApi`).

Put together, these changes enable the following testing pattern:

```scala
val jdbResultSet: ResultSet = conn.prepareStatement(query).executeQuery()
val resultSchema: StructType = JdbcUtils.getSchema(jdbResultSet, JdbcDialects.get("jdbc:postgresql"))
val jdbcRows: Seq[Row] = JdbcUtils.resultSetToRows(jdbResultSet, schema).toSeq
checkAnswer(sparkResult, jdbcRows) // in a test case
```

Author: Josh Rosen <joshrosen@databricks.com>

Closes #14907 from JoshRosen/modularize-jdbc-internals.
2016-09-02 18:53:12 +02:00
Robert Kruszewski 806d8a8e98 [SPARK-16984][SQL] don't try whole dataset immediately when first partition doesn't have…
## What changes were proposed in this pull request?

Try increase number of partitions to try so we don't revert to all.

## How was this patch tested?

Empirically. This is common case optimization.

Author: Robert Kruszewski <robertk@palantir.com>

Closes #14573 from robert3005/robertk/execute-take-backoff.
2016-09-02 17:14:43 +02:00
gatorsmile 247a4faf06 [SPARK-16935][SQL] Verification of Function-related ExternalCatalog APIs
### What changes were proposed in this pull request?
Function-related `HiveExternalCatalog` APIs do not have enough verification logics. After the PR, `HiveExternalCatalog` and `InMemoryCatalog` become consistent in the error handling.

For example, below is the exception we got when calling `renameFunction`.
```
15:13:40.369 WARN org.apache.hadoop.hive.metastore.ObjectStore: Failed to get database db1, returning NoSuchObjectException
15:13:40.377 WARN org.apache.hadoop.hive.metastore.ObjectStore: Failed to get database db2, returning NoSuchObjectException
15:13:40.739 ERROR DataNucleus.Datastore.Persist: Update of object "org.apache.hadoop.hive.metastore.model.MFunction205629e9" using statement "UPDATE FUNCS SET FUNC_NAME=? WHERE FUNC_ID=?" failed : org.apache.derby.shared.common.error.DerbySQLIntegrityConstraintViolationException: The statement was aborted because it would have caused a duplicate key value in a unique or primary key constraint or unique index identified by 'UNIQUEFUNCTION' defined on 'FUNCS'.
	at org.apache.derby.impl.jdbc.SQLExceptionFactory.getSQLException(Unknown Source)
	at org.apache.derby.impl.jdbc.Util.generateCsSQLException(Unknown Source)
	at org.apache.derby.impl.jdbc.TransactionResourceImpl.wrapInSQLException(Unknown Source)
	at org.apache.derby.impl.jdbc.TransactionResourceImpl.handleException(Unknown Source)
```

### How was this patch tested?
Improved the existing test cases to check whether the messages are right.

Author: gatorsmile <gatorsmile@gmail.com>

Closes #14521 from gatorsmile/functionChecking.
2016-09-02 22:31:01 +08:00
Jacek Laskowski a3097e2b31 [SQL][DOC][MINOR] Add (Scala-specific) and (Java-specific)
## What changes were proposed in this pull request?

Adds (Scala-specific) and (Java-specific) to Scaladoc.

## How was this patch tested?

local build

Author: Jacek Laskowski <jacek@japila.pl>

Closes #14891 from jaceklaskowski/scala-specifics.
2016-09-02 10:25:42 +01:00
Brian Cho f2d6e2ef23 [SPARK-16926][SQL] Add unit test to compare table and partition column metadata.
## What changes were proposed in this pull request?

Add unit test for changes made in PR #14515. It makes sure that a newly created table has the same number of columns in table and partition metadata. This test fails before the changes introduced in #14515.

## How was this patch tested?

Run new unit test.

Author: Brian Cho <bcho@fb.com>

Closes #14930 from dafrista/partition-metadata-unit-test.
2016-09-02 11:12:34 +08:00
Lianhui Wang 06e33985c6 [SPARK-16302][SQL] Set the right number of partitions for reading data from a local collection.
follow #13137 This pr sets the right number of partitions when reading data from a local collection.
Query 'val df = Seq((1, 2)).toDF("key", "value").count' always use defaultParallelism tasks. So it causes run many empty or small tasks.

Manually tested and checked.

Author: Lianhui Wang <lianhuiwang09@gmail.com>

Closes #13979 from lianhuiwang/localTable-Parallel.
2016-09-01 17:09:23 -07:00
Qifan Pu 03d77af9ec [SPARK-16525] [SQL] Enable Row Based HashMap in HashAggregateExec
## What changes were proposed in this pull request?

This PR is the second step for the following feature:

For hash aggregation in Spark SQL, we use a fast aggregation hashmap to act as a "cache" in order to boost aggregation performance. Previously, the hashmap is backed by a `ColumnarBatch`. This has performance issues when we have wide schema for the aggregation table (large number of key fields or value fields).
In this JIRA, we support another implementation of fast hashmap, which is backed by a `RowBatch`. We then automatically pick between the two implementations based on certain knobs.

In this second-step PR, we enable `RowBasedHashMapGenerator` in `HashAggregateExec`.

## How was this patch tested?

Added tests: `RowBasedAggregateHashMapSuite` and ` VectorizedAggregateHashMapSuite`
Additional micro-benchmarks tests and TPCDS results will be added in a separate PR in the series.

Author: Qifan Pu <qifan.pu@gmail.com>
Author: ooq <qifan.pu@gmail.com>

Closes #14176 from ooq/rowbasedfastaggmap-pr2.
2016-09-01 16:56:35 -07:00
Josh Rosen 15539e54c2 [SPARK-17355] Workaround for HIVE-14684 / HiveResultSetMetaData.isSigned exception
## What changes were proposed in this pull request?

Attempting to use Spark SQL's JDBC data source against the Hive ThriftServer results in a `java.sql.SQLException: Method` not supported exception from `org.apache.hive.jdbc.HiveResultSetMetaData.isSigned`. Here are two user reports of this issue:

- https://stackoverflow.com/questions/34067686/spark-1-5-1-not-working-with-hive-jdbc-1-2-0
- https://stackoverflow.com/questions/32195946/method-not-supported-in-spark

I have filed [HIVE-14684](https://issues.apache.org/jira/browse/HIVE-14684) to attempt to fix this in Hive by implementing the isSigned method, but in the meantime / for compatibility with older JDBC drivers I think we should add special-case error handling to work around this bug.

This patch updates `JDBCRDD`'s `ResultSetMetadata` to schema conversion to catch the "Method not supported" exception from Hive and return `isSigned = true`. I believe that this is safe because, as far as I know, Hive does not support unsigned numeric types.

## How was this patch tested?

Tested manually against a Spark Thrift Server.

Author: Josh Rosen <joshrosen@databricks.com>

Closes #14911 from JoshRosen/hive-jdbc-workaround.
2016-09-01 16:45:26 -07:00
hyukjinkwon d314677cfd [SPARK-16461][SQL] Support partition batch pruning with <=> predicate in InMemoryTableScanExec
## What changes were proposed in this pull request?

It seems `EqualNullSafe` filter was missed for batch pruneing partitions in cached tables.

It seems supporting this improves the performance roughly 5 times faster.

Running the codes below:

```scala
test("Null-safe equal comparison") {
  val N = 20000000
  val df = spark.range(N).repartition(20)
  val benchmark = new Benchmark("Null-safe equal comparison", N)
  df.createOrReplaceTempView("t")
  spark.catalog.cacheTable("t")
  sql("select id from t where id <=> 1").collect()

  benchmark.addCase("Null-safe equal comparison", 10) { _ =>
    sql("select id from t where id <=> 1").collect()
  }
  benchmark.run()
}
```

produces the results below:

**Before:**

```
Running benchmark: Null-safe equal comparison
  Running case: Null-safe equal comparison
  Stopped after 10 iterations, 2098 ms

Java HotSpot(TM) 64-Bit Server VM 1.8.0_45-b14 on Mac OS X 10.11.5
Intel(R) Core(TM) i7-4850HQ CPU  2.30GHz

Null-safe equal comparison:              Best/Avg Time(ms)    Rate(M/s)   Per Row(ns)   Relative
------------------------------------------------------------------------------------------------
Null-safe equal comparison                     204 /  210         98.1          10.2       1.0X
```

**After:**

```
Running benchmark: Null-safe equal comparison
  Running case: Null-safe equal comparison
  Stopped after 10 iterations, 478 ms

Java HotSpot(TM) 64-Bit Server VM 1.8.0_45-b14 on Mac OS X 10.11.5
Intel(R) Core(TM) i7-4850HQ CPU  2.30GHz

Null-safe equal comparison:              Best/Avg Time(ms)    Rate(M/s)   Per Row(ns)   Relative
------------------------------------------------------------------------------------------------
Null-safe equal comparison                      42 /   48        474.1           2.1       1.0X
```

## How was this patch tested?

Unit tests in `PartitionBatchPruningSuite`.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #14117 from HyukjinKwon/SPARK-16461.
2016-09-01 15:32:07 -07:00
Yucai Yu e388bd5449 [SPARK-16732][SQL] Remove unused codes in subexpressionEliminationForWholeStageCodegen
## What changes were proposed in this pull request?
Some codes in subexpressionEliminationForWholeStageCodegen are never used actually.
Remove them using this PR.

## How was this patch tested?
Local unit tests.

Author: Yucai Yu <yucai.yu@intel.com>

Closes #14366 from yucai/subExpr_unused_codes.
2016-09-01 14:13:38 -07:00
Brian Cho 473d78649d [SPARK-16926] [SQL] Remove partition columns from partition metadata.
## What changes were proposed in this pull request?

This removes partition columns from column metadata of partitions to match tables.

A change introduced in SPARK-14388 removed partition columns from the column metadata of tables, but not for partitions. This causes TableReader to believe that the schema is different between table and partition, and create an unnecessary conversion object inspector in TableReader.

## How was this patch tested?

Existing unit tests.

Author: Brian Cho <bcho@fb.com>

Closes #14515 from dafrista/partition-columns-metadata.
2016-09-01 14:13:17 -07:00
Sean Owen 3893e8c576 [SPARK-17331][CORE][MLLIB] Avoid allocating 0-length arrays
## What changes were proposed in this pull request?

Avoid allocating some 0-length arrays, esp. in UTF8String, and by using Array.empty in Scala over Array[T]()

## How was this patch tested?

Jenkins

Author: Sean Owen <sowen@cloudera.com>

Closes #14895 from srowen/SPARK-17331.
2016-09-01 12:13:07 -07:00
Herman van Hovell 2be5f8d7e0 [SPARK-17263][SQL] Add hexadecimal literal parsing
## What changes were proposed in this pull request?
This PR adds the ability to parse SQL (hexadecimal) binary literals (AKA bit strings). It follows the following syntax `X'[Hexadecimal Characters]+'`, for example: `X'01AB'` would create a binary the following binary array `0x01AB`.

If an uneven number of hexadecimal characters is passed, then the upper 4 bits of the initial byte are kept empty, and the lower 4 bits are filled using the first character. For example `X'1C7'` would create the following binary array `0x01C7`.

Binary data (Array[Byte]) does not have a proper `hashCode` and `equals` functions. This meant that comparing `Literal`s containing binary data was a pain. I have updated Literal.hashCode and Literal.equals to deal properly with binary data.

## How was this patch tested?
Added tests to the `ExpressionParserSuite`, `SQLQueryTestSuite` and `ExpressionSQLBuilderSuite`.

Author: Herman van Hovell <hvanhovell@databricks.com>

Closes #14832 from hvanhovell/SPARK-17263.
2016-09-01 12:01:22 -07:00
Tejas Patil adaaffa34e [SPARK-17271][SQL] Remove redundant semanticEquals() from SortOrder
## What changes were proposed in this pull request?

Removing `semanticEquals()` from `SortOrder` because it can use the `semanticEquals()` provided by its parent class (`Expression`). This was as per suggestion by cloud-fan at 7192418b3a (r77106801)

## How was this patch tested?

Ran the test added in https://github.com/apache/spark/pull/14841

Author: Tejas Patil <tejasp@fb.com>

Closes #14910 from tejasapatil/SPARK-17271_remove_semantic_ordering.
2016-09-01 16:47:37 +08:00
Wenchen Fan 8e740ae44d [SPARK-17257][SQL] the physical plan of CREATE TABLE or CTAS should take CatalogTable
## What changes were proposed in this pull request?

This is kind of a follow-up of https://github.com/apache/spark/pull/14482 . As we put `CatalogTable` in the logical plan directly, it makes sense to let physical plans take `CatalogTable` directly, instead of extracting some fields of `CatalogTable` in planner and then construct a new `CatalogTable` in physical plan.

## How was this patch tested?

existing tests.

Author: Wenchen Fan <wenchen@databricks.com>

Closes #14823 from cloud-fan/create-table.
2016-09-01 16:45:22 +08:00
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
Sean Zhong a18c169fd0 [SPARK-16283][SQL] Implements percentile_approx aggregation function which supports partial aggregation.
## What changes were proposed in this pull request?

This PR implements aggregation function `percentile_approx`. Function `percentile_approx` returns the approximate percentile(s) of a column at the given percentage(s). A percentile is a watermark value below which a given percentage of the column values fall. For example, the percentile of column `col` at percentage 50% is the median value of column `col`.

### Syntax:
```
# Returns percentile at a given percentage value. The approximation error can be reduced by increasing parameter accuracy, at the cost of memory.
percentile_approx(col, percentage [, accuracy])

# Returns percentile value array at given percentage value array
percentile_approx(col, array(percentage1 [, percentage2]...) [, accuracy])
```

### Features:
1. This function supports partial aggregation.
2. The memory consumption is bounded. The larger `accuracy` parameter we choose, we smaller error we get. The default accuracy value is 10000, to match with Hive default setting. Choose a smaller value for smaller memory footprint.
3.  This function supports window function aggregation.

### Example usages:
```
## Returns the 25th percentile value, with default accuracy
SELECT percentile_approx(col, 0.25) FROM table

## Returns an array of percentile value (25th, 50th, 75th), with default accuracy
SELECT percentile_approx(col, array(0.25, 0.5, 0.75)) FROM table

## Returns 25th percentile value, with custom accuracy value 100, larger accuracy parameter yields smaller approximation error
SELECT percentile_approx(col, 0.25, 100) FROM table

## Returns the 25th, and 50th percentile values, with custom accuracy value 100
SELECT percentile_approx(col, array(0.25, 0.5), 100) FROM table
```

### NOTE:
1. The `percentile_approx` implementation is different from Hive, so the result returned on same query maybe slightly different with Hive. This implementation uses `QuantileSummaries` as the underlying probabilistic data structure, and mainly follows paper `Space-efficient Online Computation of Quantile Summaries` by Greenwald, Michael and Khanna, Sanjeev. (http://dx.doi.org/10.1145/375663.375670)`
2. The current implementation of `QuantileSummaries` doesn't support automatic compression. This PR has a rule to do compression automatically at the caller side, but it may not be optimal.

## How was this patch tested?

Unit test, and Sql query test.

## Acknowledgement
1. This PR's work in based on lw-lin's PR https://github.com/apache/spark/pull/14298, with improvements like supporting partial aggregation, fixing out of memory issue.

Author: Sean Zhong <seanzhong@databricks.com>

Closes #14868 from clockfly/appro_percentile_try_2.
2016-09-01 16:31:13 +08:00
Wenchen Fan aaf632b213 revert PR#10896 and PR#14865
## What changes were proposed in this pull request?

according to the discussion in the original PR #10896 and the new approach PR #14876 , we decided to revert these 2 PRs and go with the new approach.

## How was this patch tested?

N/A

Author: Wenchen Fan <wenchen@databricks.com>

Closes #14909 from cloud-fan/revert.
2016-09-01 13:19:15 +08:00
Wenchen Fan 12fd0cd615 [SPARK-17180][SPARK-17309][SPARK-17323][SQL] create AlterViewAsCommand to handle ALTER VIEW AS
## What changes were proposed in this pull request?

Currently we use `CreateViewCommand` to implement ALTER VIEW AS, which has 3 bugs:

1. SPARK-17180: ALTER VIEW AS should alter temp view if view name has no database part and temp view exists
2. SPARK-17309: ALTER VIEW AS should issue exception if view does not exist.
3. SPARK-17323: ALTER VIEW AS should keep the previous table properties, comment, create_time, etc.

The root cause is, ALTER VIEW AS is quite different from CREATE VIEW, we need different code path to handle them. However, in `CreateViewCommand`, there is no way to distinguish ALTER VIEW AS and CREATE VIEW, we have to introduce extra flag. But instead of doing this, I think a more natural way is to separate the ALTER VIEW AS logic into a new command.

## How was this patch tested?

new tests in SQLViewSuite

Author: Wenchen Fan <wenchen@databricks.com>

Closes #14874 from cloud-fan/minor4.
2016-08-31 17:08:08 +08:00
Kazuaki Ishizaki d92cd227cf [SPARK-15985][SQL] Eliminate redundant cast from an array without null or a map without null
## What changes were proposed in this pull request?

This PR eliminates redundant cast from an `ArrayType` with `containsNull = false` or a `MapType` with `containsNull = false`.

For example, in `ArrayType` case, current implementation leaves a cast `cast(value#63 as array<double>).toDoubleArray`. However, we can eliminate `cast(value#63 as array<double>)` if we know `value#63` does not include `null`. This PR apply this elimination for `ArrayType` and `MapType` in `SimplifyCasts` at a plan optimization phase.

In summary, we got 1.2-1.3x performance improvements over the code before applying this PR.
Here are performance results of benchmark programs:
```
  test("Read array in Dataset") {
    import sparkSession.implicits._

    val iters = 5
    val n = 1024 * 1024
    val rows = 15

    val benchmark = new Benchmark("Read primnitive array", n)

    val rand = new Random(511)
    val intDS = sparkSession.sparkContext.parallelize(0 until rows, 1)
      .map(i => Array.tabulate(n)(i => i)).toDS()
    intDS.count() // force to create ds
    val lastElement = n - 1
    val randElement = rand.nextInt(lastElement)

    benchmark.addCase(s"Read int array in Dataset", numIters = iters)(iter => {
      val idx0 = randElement
      val idx1 = lastElement
      intDS.map(a => a(0) + a(idx0) + a(idx1)).collect
    })

    val doubleDS = sparkSession.sparkContext.parallelize(0 until rows, 1)
      .map(i => Array.tabulate(n)(i => i.toDouble)).toDS()
    doubleDS.count() // force to create ds

    benchmark.addCase(s"Read double array in Dataset", numIters = iters)(iter => {
      val idx0 = randElement
      val idx1 = lastElement
      doubleDS.map(a => a(0) + a(idx0) + a(idx1)).collect
    })

    benchmark.run()
  }

Java HotSpot(TM) 64-Bit Server VM 1.8.0_92-b14 on Mac OS X 10.10.4
Intel(R) Core(TM) i5-5257U CPU  2.70GHz

without this PR
Read primnitive array:                   Best/Avg Time(ms)    Rate(M/s)   Per Row(ns)   Relative
------------------------------------------------------------------------------------------------
Read int array in Dataset                      525 /  690          2.0         500.9       1.0X
Read double array in Dataset                   947 / 1209          1.1         902.7       0.6X

with this PR
Read primnitive array:                   Best/Avg Time(ms)    Rate(M/s)   Per Row(ns)   Relative
------------------------------------------------------------------------------------------------
Read int array in Dataset                      400 /  492          2.6         381.5       1.0X
Read double array in Dataset                   788 /  870          1.3         751.4       0.5X
```

An example program that originally caused this performance issue.
```
val ds = Seq(Array(1.0, 2.0, 3.0), Array(4.0, 5.0, 6.0)).toDS()
val ds2 = ds.map(p => {
     var s = 0.0
     for (i <- 0 to 2) { s += p(i) }
     s
   })
ds2.show
ds2.explain(true)
```

Plans before this PR
```
== Parsed Logical Plan ==
'SerializeFromObject [input[0, double, true] AS value#68]
+- 'MapElements <function1>, obj#67: double
   +- 'DeserializeToObject unresolveddeserializer(upcast(getcolumnbyordinal(0, ArrayType(DoubleType,false)), ArrayType(DoubleType,false), - root class: "scala.Array").toDoubleArray), obj#66: [D
      +- LocalRelation [value#63]

== Analyzed Logical Plan ==
value: double
SerializeFromObject [input[0, double, true] AS value#68]
+- MapElements <function1>, obj#67: double
   +- DeserializeToObject cast(value#63 as array<double>).toDoubleArray, obj#66: [D
      +- LocalRelation [value#63]

== Optimized Logical Plan ==
SerializeFromObject [input[0, double, true] AS value#68]
+- MapElements <function1>, obj#67: double
   +- DeserializeToObject cast(value#63 as array<double>).toDoubleArray, obj#66: [D
      +- LocalRelation [value#63]

== Physical Plan ==
*SerializeFromObject [input[0, double, true] AS value#68]
+- *MapElements <function1>, obj#67: double
   +- *DeserializeToObject cast(value#63 as array<double>).toDoubleArray, obj#66: [D
      +- LocalTableScan [value#63]
```

Plans after this PR
```
== Parsed Logical Plan ==
'SerializeFromObject [input[0, double, true] AS value#6]
+- 'MapElements <function1>, obj#5: double
   +- 'DeserializeToObject unresolveddeserializer(upcast(getcolumnbyordinal(0, ArrayType(DoubleType,false)), ArrayType(DoubleType,false), - root class: "scala.Array").toDoubleArray), obj#4: [D
      +- LocalRelation [value#1]

== Analyzed Logical Plan ==
value: double
SerializeFromObject [input[0, double, true] AS value#6]
+- MapElements <function1>, obj#5: double
   +- DeserializeToObject cast(value#1 as array<double>).toDoubleArray, obj#4: [D
      +- LocalRelation [value#1]

== Optimized Logical Plan ==
SerializeFromObject [input[0, double, true] AS value#6]
+- MapElements <function1>, obj#5: double
   +- DeserializeToObject value#1.toDoubleArray, obj#4: [D
      +- LocalRelation [value#1]

== Physical Plan ==
*SerializeFromObject [input[0, double, true] AS value#6]
+- *MapElements <function1>, obj#5: double
   +- *DeserializeToObject value#1.toDoubleArray, obj#4: [D
      +- LocalTableScan [value#1]
```

## How was this patch tested?

Tested by new test cases in `SimplifyCastsSuite`

Author: Kazuaki Ishizaki <ishizaki@jp.ibm.com>

Closes #13704 from kiszk/SPARK-15985.
2016-08-31 12:40:53 +08:00
Xin Ren 27209252f0 [MINOR][MLLIB][SQL] Clean up unused variables and unused import
## What changes were proposed in this pull request?

Clean up unused variables and unused import statements, unnecessary `return` and `toArray`, and some more style improvement,  when I walk through the code examples.

## How was this patch tested?

Testet manually on local laptop.

Author: Xin Ren <iamshrek@126.com>

Closes #14836 from keypointt/codeWalkThroughML.
2016-08-30 11:24:55 +01:00
Sean Owen befab9c1c6 [SPARK-17264][SQL] DataStreamWriter should document that it only supports Parquet for now
## What changes were proposed in this pull request?

Clarify that only parquet files are supported by DataStreamWriter now

## How was this patch tested?

(Doc build -- no functional changes to test)

Author: Sean Owen <sowen@cloudera.com>

Closes #14860 from srowen/SPARK-17264.
2016-08-30 11:19:45 +01:00
Xin Ren 2d76cb11f5 [SPARK-17276][CORE][TEST] Stop env params output on Jenkins job page
https://issues.apache.org/jira/browse/SPARK-17276

## What changes were proposed in this pull request?

When trying to find error msg in a failed Jenkins build job, I'm annoyed by the huge env output.
The env parameter output should be muted.

![screen shot 2016-08-26 at 10 52 07 pm](https://cloud.githubusercontent.com/assets/3925641/18025581/b8d567ba-6be2-11e6-9eeb-6aec223f1730.png)

## How was this patch tested?

Tested manually on local laptop.

Author: Xin Ren <iamshrek@126.com>

Closes #14848 from keypointt/SPARK-17276.
2016-08-30 11:18:29 +01:00
gatorsmile bca79c8230 [SPARK-17234][SQL] Table Existence Checking when Index Table with the Same Name Exists
### What changes were proposed in this pull request?
Hive Index tables are not supported by Spark SQL. Thus, we issue an exception when users try to access Hive Index tables. When the internal function `tableExists` tries to access Hive Index tables, it always gets the same error message: ```Hive index table is not supported```. This message could be confusing to users, since their SQL operations could be completely unrelated to Hive Index tables. For example, when users try to alter a table to a new name and there exists an index table with the same name, the expected exception should be a `TableAlreadyExistsException`.

This PR made the following changes:
- Introduced a new `AnalysisException` type: `SQLFeatureNotSupportedException`. When users try to access an `Index Table`, we will issue a `SQLFeatureNotSupportedException`.
- `tableExists` returns `true` when hitting a `SQLFeatureNotSupportedException` and the feature is `Hive index table`.
- Add a checking `requireTableNotExists` for `SessionCatalog`'s `createTable` API; otherwise, the current implementation relies on the Hive's internal checking.

### How was this patch tested?
Added a test case

Author: gatorsmile <gatorsmile@gmail.com>

Closes #14801 from gatorsmile/tableExists.
2016-08-30 17:27:00 +08:00
Takeshi YAMAMURO 94922d79e9 [SPARK-17289][SQL] Fix a bug to satisfy sort requirements in partial aggregations
## What changes were proposed in this pull request?
Partial aggregations are generated in `EnsureRequirements`, but the planner fails to
check if partial aggregation satisfies sort requirements.
For the following query:
```
val df2 = (0 to 1000).map(x => (x % 2, x.toString)).toDF("a", "b").createOrReplaceTempView("t2")
spark.sql("select max(b) from t2 group by a").explain(true)
```
Now, the SortAggregator won't insert Sort operator before partial aggregation, this will break sort-based partial aggregation.
```
== Physical Plan ==
SortAggregate(key=[a#5], functions=[max(b#6)], output=[max(b)#17])
+- *Sort [a#5 ASC], false, 0
   +- Exchange hashpartitioning(a#5, 200)
      +- SortAggregate(key=[a#5], functions=[partial_max(b#6)], output=[a#5, max#19])
         +- LocalTableScan [a#5, b#6]
```
Actually, a correct plan is:
```
== Physical Plan ==
SortAggregate(key=[a#5], functions=[max(b#6)], output=[max(b)#17])
+- *Sort [a#5 ASC], false, 0
   +- Exchange hashpartitioning(a#5, 200)
      +- SortAggregate(key=[a#5], functions=[partial_max(b#6)], output=[a#5, max#19])
         +- *Sort [a#5 ASC], false, 0
            +- LocalTableScan [a#5, b#6]
```

## How was this patch tested?
Added tests in `PlannerSuite`.

Author: Takeshi YAMAMURO <linguin.m.s@gmail.com>

Closes #14865 from maropu/SPARK-17289.
2016-08-30 16:43:47 +08:00
Josh Rosen 48b459ddd5 [SPARK-17301][SQL] Remove unused classTag field from AtomicType base class
There's an unused `classTag` val in the AtomicType base class which is causing unnecessary slowness in deserialization because it needs to grab ScalaReflectionLock and create a new runtime reflection mirror. Removing this unused code gives a small but measurable performance boost in SQL task deserialization.

Author: Josh Rosen <joshrosen@databricks.com>

Closes #14869 from JoshRosen/remove-unused-classtag.
2016-08-30 09:58:00 +08:00
Davies Liu 48caec2516 [SPARK-17063] [SQL] Improve performance of MSCK REPAIR TABLE with Hive metastore
## What changes were proposed in this pull request?

This PR split the the single `createPartitions()` call into smaller batches, which could prevent Hive metastore from OOM (caused by millions of partitions).

It will also try to gather all the fast stats (number of files and total size of all files) in parallel to avoid the bottle neck of listing the files in metastore sequential, which is controlled by spark.sql.gatherFastStats (enabled by default).

## How was this patch tested?

Tested locally with 10000 partitions and 100 files with embedded metastore, without gathering fast stats in parallel, adding partitions took 153 seconds, after enable that, gathering the fast stats took about 34 seconds, adding these partitions took 25 seconds (most of the time spent in object store), 59 seconds in total, 2.5X faster (with larger cluster, gathering will much faster).

Author: Davies Liu <davies@databricks.com>

Closes #14607 from davies/repair_batch.
2016-08-29 11:23:53 -07:00
Tejas Patil 095862a3cf [SPARK-17271][SQL] Planner adds un-necessary Sort even if child ordering is semantically same as required ordering
## What changes were proposed in this pull request?

Jira : https://issues.apache.org/jira/browse/SPARK-17271

Planner is adding un-needed SORT operation due to bug in the way comparison for `SortOrder` is done at https://github.com/apache/spark/blob/master/sql/core/src/main/scala/org/apache/spark/sql/execution/exchange/EnsureRequirements.scala#L253
`SortOrder` needs to be compared semantically because `Expression` within two `SortOrder` can be "semantically equal" but not literally equal objects.

eg. In case of `sql("SELECT * FROM table1 a JOIN table2 b ON a.col1=b.col1")`

Expression in required SortOrder:
```
      AttributeReference(
        name = "col1",
        dataType = LongType,
        nullable = false
      ) (exprId = exprId,
        qualifier = Some("a")
      )
```

Expression in child SortOrder:
```
      AttributeReference(
        name = "col1",
        dataType = LongType,
        nullable = false
      ) (exprId = exprId)
```

Notice that the output column has a qualifier but the child attribute does not but the inherent expression is the same and hence in this case we can say that the child satisfies the required sort order.

This PR includes following changes:
- Added a `semanticEquals` method to `SortOrder` so that it can compare underlying child expressions semantically (and not using default Object.equals)
- Fixed `EnsureRequirements` to use semantic comparison of SortOrder

## How was this patch tested?

- Added a test case to `PlannerSuite`. Ran rest tests in `PlannerSuite`

Author: Tejas Patil <tejasp@fb.com>

Closes #14841 from tejasapatil/SPARK-17271_sort_order_equals_bug.
2016-08-28 19:14:58 +02:00
Takeshi YAMAMURO cd0ed31ea9 [SPARK-15382][SQL] Fix a bug in sampling with replacement
## What changes were proposed in this pull request?
This pr to fix a bug below in sampling with replacement
```
val df = Seq((1, 0), (2, 0), (3, 0)).toDF("a", "b")
df.sample(true, 2.0).withColumn("c", monotonically_increasing_id).select($"c").show
+---+
|  c|
+---+
|  0|
|  1|
|  1|
|  1|
|  2|
+---+
```

## How was this patch tested?
Added a test in `DataFrameSuite`.

Author: Takeshi YAMAMURO <linguin.m.s@gmail.com>

Closes #14800 from maropu/FixSampleBug.
2016-08-27 08:42:41 +01:00
Reynold Xin 718b6bad2d [SPARK-17274][SQL] Move join optimizer rules into a separate file
## What changes were proposed in this pull request?
As part of breaking Optimizer.scala apart, this patch moves various join rules into a single file.

## How was this patch tested?
This should be covered by existing tests.

Author: Reynold Xin <rxin@databricks.com>

Closes #14846 from rxin/SPARK-17274.
2016-08-27 00:36:18 -07:00
Reynold Xin 5aad4509c1 [SPARK-17273][SQL] Move expression optimizer rules into a separate file
## What changes were proposed in this pull request?
As part of breaking Optimizer.scala apart, this patch moves various expression optimization rules into a single file.

## How was this patch tested?
This should be covered by existing tests.

Author: Reynold Xin <rxin@databricks.com>

Closes #14845 from rxin/SPARK-17273.
2016-08-27 00:34:35 -07:00
Reynold Xin 0243b32873 [SPARK-17272][SQL] Move subquery optimizer rules into its own file
## What changes were proposed in this pull request?
As part of breaking Optimizer.scala apart, this patch moves various subquery rules into a single file.

## How was this patch tested?
This should be covered by existing tests.

Author: Reynold Xin <rxin@databricks.com>

Closes #14844 from rxin/SPARK-17272.
2016-08-27 00:32:57 -07:00
Reynold Xin dcefac4387 [SPARK-17269][SQL] Move finish analysis optimization stage into its own file
## What changes were proposed in this pull request?
As part of breaking Optimizer.scala apart, this patch moves various finish analysis optimization stage rules into a single file. I'm submitting separate pull requests so we can more easily merge this in branch-2.0 to simplify optimizer backports.

## How was this patch tested?
This should be covered by existing tests.

Author: Reynold Xin <rxin@databricks.com>

Closes #14838 from rxin/SPARK-17269.
2016-08-26 22:10:28 -07:00
Reynold Xin cc0caa690b [SPARK-17270][SQL] Move object optimization rules into its own file
## What changes were proposed in this pull request?
As part of breaking Optimizer.scala apart, this patch moves various Dataset object optimization rules into a single file. I'm submitting separate pull requests so we can more easily merge this in branch-2.0 to simplify optimizer backports.

## How was this patch tested?
This should be covered by existing tests.

Author: Reynold Xin <rxin@databricks.com>

Closes #14839 from rxin/SPARK-17270.
2016-08-26 21:41:58 -07:00
Sameer Agarwal 540e912801 [SPARK-17244] Catalyst should not pushdown non-deterministic join conditions
## What changes were proposed in this pull request?

Given that non-deterministic expressions can be stateful, pushing them down the query plan during the optimization phase can cause incorrect behavior. This patch fixes that issue by explicitly disabling that.

## How was this patch tested?

A new test in `FilterPushdownSuite` that checks catalyst behavior for both deterministic and non-deterministic join conditions.

Author: Sameer Agarwal <sameerag@cs.berkeley.edu>

Closes #14815 from sameeragarwal/constraint-inputfile.
2016-08-26 16:40:59 -07:00
petermaxlee f64a1ddd09 [SPARK-17235][SQL] Support purging of old logs in MetadataLog
## What changes were proposed in this pull request?
This patch adds a purge interface to MetadataLog, and an implementation in HDFSMetadataLog. The purge function is currently unused, but I will use it to purge old execution and file source logs in follow-up patches. These changes are required in a production structured streaming job that runs for a long period of time.

## How was this patch tested?
Added a unit test case in HDFSMetadataLogSuite.

Author: petermaxlee <petermaxlee@gmail.com>

Closes #14802 from petermaxlee/SPARK-17235.
2016-08-26 16:05:34 -07:00
Herman van Hovell a11d10f182 [SPARK-17246][SQL] Add BigDecimal literal
## What changes were proposed in this pull request?
This PR adds parser support for `BigDecimal` literals. If you append the suffix `BD` to a valid number then this will be interpreted as a `BigDecimal`, for example `12.0E10BD` will interpreted into a BigDecimal with scale -9 and precision 3. This is useful in situations where you need exact values.

## How was this patch tested?
Added tests to `ExpressionParserSuite`, `ExpressionSQLBuilderSuite` and `SQLQueryTestSuite`.

Author: Herman van Hovell <hvanhovell@databricks.com>

Closes #14819 from hvanhovell/SPARK-17246.
2016-08-26 13:29:22 -07:00
petermaxlee 9812f7d538 [SPARK-17165][SQL] FileStreamSource should not track the list of seen files indefinitely
## What changes were proposed in this pull request?
Before this change, FileStreamSource uses an in-memory hash set to track the list of files processed by the engine. The list can grow indefinitely, leading to OOM or overflow of the hash set.

This patch introduces a new user-defined option called "maxFileAge", default to 24 hours. If a file is older than this age, FileStreamSource will purge it from the in-memory map that was used to track the list of files that have been processed.

## How was this patch tested?
Added unit tests for the underlying utility, and also added an end-to-end test to validate the purge in FileStreamSourceSuite. Also verified the new test cases would fail when the timeout was set to a very large number.

Author: petermaxlee <petermaxlee@gmail.com>

Closes #14728 from petermaxlee/SPARK-17165.
2016-08-26 11:30:23 -07:00
gatorsmile 261c55dd88 [SPARK-17250][SQL] Remove HiveClient and setCurrentDatabase from HiveSessionCatalog
### What changes were proposed in this pull request?
This is the first step to remove `HiveClient` from `HiveSessionState`. In the metastore interaction, we always use the fully qualified table name when accessing/operating a table. That means, we always specify the database. Thus, it is not necessary to use `HiveClient` to change the active database in Hive metastore.

In `HiveSessionCatalog `, `setCurrentDatabase` is the only function that uses `HiveClient`. Thus, we can remove it after removing `setCurrentDatabase`

### How was this patch tested?
The existing test cases.

Author: gatorsmile <gatorsmile@gmail.com>

Closes #14821 from gatorsmile/setCurrentDB.
2016-08-26 11:19:03 -07:00
gatorsmile fd4ba3f626 [SPARK-17192][SQL] Issue Exception when Users Specify the Partitioning Columns without a Given Schema
### What changes were proposed in this pull request?
Address the comments by yhuai in the original PR: https://github.com/apache/spark/pull/14207

First, issue an exception instead of logging a warning when users specify the partitioning columns without a given schema.

Second, refactor the codes a little.

### How was this patch tested?
Fixed the test cases.

Author: gatorsmile <gatorsmile@gmail.com>

Closes #14572 from gatorsmile/followup16552.
2016-08-26 11:13:38 -07:00
Wenchen Fan 970ab8f6dd [SPARK-17187][SQL][FOLLOW-UP] improve document of TypedImperativeAggregate
## What changes were proposed in this pull request?

improve the document to make it easier to understand and also mention window operator.

## How was this patch tested?

N/A

Author: Wenchen Fan <wenchen@databricks.com>

Closes #14822 from cloud-fan/object-agg.
2016-08-26 10:56:57 -07:00
Wenchen Fan 28ab17922a [SPARK-17260][MINOR] move CreateTables to HiveStrategies
## What changes were proposed in this pull request?

`CreateTables` rule turns a general `CreateTable` plan to `CreateHiveTableAsSelectCommand` for hive serde table. However, this rule is logically a planner strategy, we should move it to `HiveStrategies`, to be consistent with other DDL commands.

## How was this patch tested?

existing tests.

Author: Wenchen Fan <wenchen@databricks.com>

Closes #14825 from cloud-fan/ctas.
2016-08-26 08:52:10 -07:00
hyukjinkwon 6063d5963f [SPARK-16216][SQL][FOLLOWUP] Enable timestamp type tests for JSON and verify all unsupported types in CSV
## What changes were proposed in this pull request?

This PR enables the tests for `TimestampType` for JSON and unifies the logics for verifying schema when writing in CSV.

In more details, this PR,

- Enables the tests for `TimestampType` for JSON and

  This was disabled due to an issue in `DatatypeConverter.parseDateTime` which parses dates incorrectly, for example as below:

  ```scala
   val d = javax.xml.bind.DatatypeConverter.parseDateTime("0900-01-01T00:00:00.000").getTime
  println(d.toString)
  ```
  ```
  Fri Dec 28 00:00:00 KST 899
  ```

  However, since we use `FastDateFormat`, it seems we are safe now.

  ```scala
  val d = FastDateFormat.getInstance("yyyy-MM-dd'T'HH:mm:ss.SSS").parse("0900-01-01T00:00:00.000")
  println(d)
  ```
  ```
  Tue Jan 01 00:00:00 PST 900
  ```

- Verifies all unsupported types in CSV

  There is a separate logics to verify the schemas in `CSVFileFormat`. This is actually not quite correct enough because we don't support `NullType` and `CalanderIntervalType` as well `StructType`, `ArrayType`, `MapType`. So, this PR adds both types.

## How was this patch tested?

Tests in `JsonHadoopFsRelation` and `CSVSuite`

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #14829 from HyukjinKwon/SPARK-16216-followup.
2016-08-26 17:29:37 +02:00
hyukjinkwon b964a172a8 [SPARK-17212][SQL] TypeCoercion supports widening conversion between DateType and TimestampType
## What changes were proposed in this pull request?

Currently, type-widening does not work between `TimestampType` and `DateType`.

This applies to `SetOperation`, `Union`, `In`, `CaseWhen`, `Greatest`,  `Leatest`, `CreateArray`, `CreateMap`, `Coalesce`, `NullIf`, `IfNull`, `Nvl` and `Nvl2`, .

This PR adds the support for widening `DateType` to `TimestampType` for them.

For a simple example,

**Before**

```scala
Seq(Tuple2(new Timestamp(0), new Date(0))).toDF("a", "b").selectExpr("greatest(a, b)").show()
```

shows below:

```
cannot resolve 'greatest(`a`, `b`)' due to data type mismatch: The expressions should all have the same type, got GREATEST(timestamp, date)
```

or union as below:

```scala
val a = Seq(Tuple1(new Timestamp(0))).toDF()
val b = Seq(Tuple1(new Date(0))).toDF()
a.union(b).show()
```

shows below:

```
Union can only be performed on tables with the compatible column types. DateType <> TimestampType at the first column of the second table;
```

**After**

```scala
Seq(Tuple2(new Timestamp(0), new Date(0))).toDF("a", "b").selectExpr("greatest(a, b)").show()
```

shows below:

```
+----------------------------------------------------+
|greatest(CAST(a AS TIMESTAMP), CAST(b AS TIMESTAMP))|
+----------------------------------------------------+
|                                1969-12-31 16:00:...|
+----------------------------------------------------+
```

or union as below:

```scala
val a = Seq(Tuple1(new Timestamp(0))).toDF()
val b = Seq(Tuple1(new Date(0))).toDF()
a.union(b).show()
```

shows below:

```
+--------------------+
|                  _1|
+--------------------+
|1969-12-31 16:00:...|
|1969-12-31 00:00:...|
+--------------------+
```

## How was this patch tested?

Unit tests in `TypeCoercionSuite`.

Author: hyukjinkwon <gurwls223@gmail.com>
Author: HyukjinKwon <gurwls223@gmail.com>

Closes #14786 from HyukjinKwon/SPARK-17212.
2016-08-26 08:58:43 +08:00
Sean Zhong d96d151563 [SPARK-17187][SQL] Supports using arbitrary Java object as internal aggregation buffer object
## What changes were proposed in this pull request?

This PR introduces an abstract class `TypedImperativeAggregate` so that an aggregation function of TypedImperativeAggregate can use  **arbitrary** user-defined Java object as intermediate aggregation buffer object.

**This has advantages like:**
1. It now can support larger category of aggregation functions. For example, it will be much easier to implement aggregation function `percentile_approx`, which has a complex aggregation buffer definition.
2. It can be used to avoid doing serialization/de-serialization for every call of `update` or `merge` when converting domain specific aggregation object to internal Spark-Sql storage format.
3. It is easier to integrate with other existing monoid libraries like algebird, and supports more aggregation functions with high performance.

Please see `org.apache.spark.sql.TypedImperativeAggregateSuite.TypedMaxAggregate` to find an example of how to defined a `TypedImperativeAggregate` aggregation function.
Please see Java doc of `TypedImperativeAggregate` and Jira ticket SPARK-17187 for more information.

## How was this patch tested?

Unit tests.

Author: Sean Zhong <seanzhong@databricks.com>
Author: Yin Huai <yhuai@databricks.com>

Closes #14753 from clockfly/object_aggregation_buffer_try_2.
2016-08-25 16:36:16 -07:00