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4259 commits

Author SHA1 Message Date
Tejas Patil 335491704c [SPARK-15453][SQL] FileSourceScanExec to extract outputOrdering information
## What changes were proposed in this pull request?

Jira : https://issues.apache.org/jira/browse/SPARK-15453

Extracting sort ordering information in `FileSourceScanExec` so that planner can make use of it. My motivation to make this change was to get Sort Merge join in par with Hive's Sort-Merge-Bucket join when the source tables are bucketed + sorted.

Query:

```
val df = (0 until 16).map(i => (i % 8, i * 2, i.toString)).toDF("i", "j", "k").coalesce(1)
df.write.bucketBy(8, "j", "k").sortBy("j", "k").saveAsTable("table8")
df.write.bucketBy(8, "j", "k").sortBy("j", "k").saveAsTable("table9")
context.sql("SELECT * FROM table8 a JOIN table9 b ON a.j=b.j AND a.k=b.k").explain(true)
```

Before:

```
== Physical Plan ==
*SortMergeJoin [j#120, k#121], [j#123, k#124], Inner
:- *Sort [j#120 ASC, k#121 ASC], false, 0
:  +- *Project [i#119, j#120, k#121]
:     +- *Filter (isnotnull(k#121) && isnotnull(j#120))
:        +- *FileScan orc default.table8[i#119,j#120,k#121] Batched: false, Format: ORC, InputPaths: file:/Users/tejasp/Desktop/dev/tp-spark/spark-warehouse/table8, PartitionFilters: [], PushedFilters: [IsNotNull(k), IsNotNull(j)], ReadSchema: struct<i:int,j:int,k:string>
+- *Sort [j#123 ASC, k#124 ASC], false, 0
+- *Project [i#122, j#123, k#124]
+- *Filter (isnotnull(k#124) && isnotnull(j#123))
 +- *FileScan orc default.table9[i#122,j#123,k#124] Batched: false, Format: ORC, InputPaths: file:/Users/tejasp/Desktop/dev/tp-spark/spark-warehouse/table9, PartitionFilters: [], PushedFilters: [IsNotNull(k), IsNotNull(j)], ReadSchema: struct<i:int,j:int,k:string>
```

After:  (note that the `Sort` step is no longer there)

```
== Physical Plan ==
*SortMergeJoin [j#49, k#50], [j#52, k#53], Inner
:- *Project [i#48, j#49, k#50]
:  +- *Filter (isnotnull(k#50) && isnotnull(j#49))
:     +- *FileScan orc default.table8[i#48,j#49,k#50] Batched: false, Format: ORC, InputPaths: file:/Users/tejasp/Desktop/dev/tp-spark/spark-warehouse/table8, PartitionFilters: [], PushedFilters: [IsNotNull(k), IsNotNull(j)], ReadSchema: struct<i:int,j:int,k:string>
+- *Project [i#51, j#52, k#53]
   +- *Filter (isnotnull(j#52) && isnotnull(k#53))
      +- *FileScan orc default.table9[i#51,j#52,k#53] Batched: false, Format: ORC, InputPaths: file:/Users/tejasp/Desktop/dev/tp-spark/spark-warehouse/table9, PartitionFilters: [], PushedFilters: [IsNotNull(j), IsNotNull(k)], ReadSchema: struct<i:int,j:int,k:string>
```

## How was this patch tested?

Added a test case in `JoinSuite`. Ran all other tests in `JoinSuite`

Author: Tejas Patil <tejasp@fb.com>

Closes #14864 from tejasapatil/SPARK-15453_smb_optimization.
2016-09-10 09:27:22 +08:00
hyukjinkwon f7d2143705 [SPARK-17354] [SQL] Partitioning by dates/timestamps should work with Parquet vectorized reader
## What changes were proposed in this pull request?

This PR fixes `ColumnVectorUtils.populate` so that Parquet vectorized reader can read partitioned table with dates/timestamps. This works fine with Parquet normal reader.

This is being only called within [VectorizedParquetRecordReader.java#L185](https://github.com/apache/spark/blob/master/sql/core/src/main/java/org/apache/spark/sql/execution/datasources/parquet/VectorizedParquetRecordReader.java#L185).

When partition column types are explicitly given to `DateType` or `TimestampType` (rather than inferring the type of partition column), this fails with the exception below:

```
16/09/01 10:30:07 ERROR Executor: Exception in task 0.0 in stage 5.0 (TID 6)
java.lang.ClassCastException: java.lang.Integer cannot be cast to java.sql.Date
	at org.apache.spark.sql.execution.vectorized.ColumnVectorUtils.populate(ColumnVectorUtils.java:89)
	at org.apache.spark.sql.execution.datasources.parquet.VectorizedParquetRecordReader.initBatch(VectorizedParquetRecordReader.java:185)
	at org.apache.spark.sql.execution.datasources.parquet.VectorizedParquetRecordReader.initBatch(VectorizedParquetRecordReader.java:204)
	at org.apache.spark.sql.execution.datasources.parquet.ParquetFileFormat$$anonfun$buildReader$1.apply(ParquetFileFormat.scala:362)
...
```

## How was this patch tested?

Unit tests in `SQLQuerySuite`.

Author: hyukjinkwon <gurwls223@gmail.com>

Closes #14919 from HyukjinKwon/SPARK-17354.
2016-09-09 14:23:05 -07:00
Eric Liang 722afbb2b3 [SPARK-17405] RowBasedKeyValueBatch should use default page size to prevent OOMs
## What changes were proposed in this pull request?

Before this change, we would always allocate 64MB per aggregation task for the first-level hash map storage, even when running in low-memory situations such as local mode. This changes it to use the memory manager default page size, which is automatically reduced from 64MB in these situations.

cc ooq JoshRosen

## How was this patch tested?

Tested manually with `bin/spark-shell --master=local[32]` and verifying that `(1 to math.pow(10, 3).toInt).toDF("n").withColumn("m", 'n % 2).groupBy('m).agg(sum('n)).show` does not crash.

Author: Eric Liang <ekl@databricks.com>

Closes #15016 from ericl/sc-4483.
2016-09-08 16:47:18 -07:00
Wenchen Fan 3ced39df32 [SPARK-17432][SQL] PreprocessDDL should respect case sensitivity when checking duplicated columns
## What changes were proposed in this pull request?

In `PreprocessDDL` we will check if table columns are duplicated. However, this checking ignores case sensitivity config(it's always case-sensitive) and lead to different result between `HiveExternalCatalog` and `InMemoryCatalog`. `HiveExternalCatalog` will throw exception because hive metastore is always case-nonsensitive, and `InMemoryCatalog` is fine.

This PR fixes it.

## How was this patch tested?

a new test in DDLSuite

Author: Wenchen Fan <wenchen@databricks.com>

Closes #14994 from cloud-fan/check-dup.
2016-09-08 19:41:49 +08:00
gatorsmile b230fb92a5 [SPARK-17052][SQL] Remove Duplicate Test Cases auto_join from HiveCompatibilitySuite.scala
### What changes were proposed in this pull request?
The original [JIRA Hive-1642](https://issues.apache.org/jira/browse/HIVE-1642) delivered the test cases `auto_joinXYZ` for verifying the results when the joins are automatically converted to map-join. Basically, most of them are just copied from the corresponding `joinXYZ`.

After comparison between `auto_joinXYZ` and `joinXYZ`, below is a list of duplicate cases:
```
    "auto_join0",
    "auto_join1",
    "auto_join10",
    "auto_join11",
    "auto_join12",
    "auto_join13",
    "auto_join14",
    "auto_join14_hadoop20",
    "auto_join15",
    "auto_join17",
    "auto_join18",
    "auto_join2",
    "auto_join20",
    "auto_join21",
    "auto_join23",
    "auto_join24",
    "auto_join3",
    "auto_join4",
    "auto_join5",
    "auto_join6",
    "auto_join7",
    "auto_join8",
    "auto_join9"
```

We can remove all of them without affecting the test coverage.

### How was this patch tested?
N/A

Author: gatorsmile <gatorsmile@gmail.com>

Closes #14635 from gatorsmile/removeAuto.
2016-09-07 14:03:14 -07:00
Srinivasa Reddy Vundela 76ad89e924 [MINOR][SQL] Fixing the typo in unit test
## What changes were proposed in this pull request?

Fixing the typo in the unit test of CodeGenerationSuite.scala

## How was this patch tested?
Ran the unit test after fixing the typo and it passes

Author: Srinivasa Reddy Vundela <vsr@cloudera.com>

Closes #14989 from vundela/typo_fix.
2016-09-07 12:41:03 +01:00
Daoyuan Wang 6f4aeccf8c [SPARK-17427][SQL] function SIZE should return -1 when parameter is null
## What changes were proposed in this pull request?

`select size(null)` returns -1 in Hive. In order to be compatible, we should return `-1`.

## How was this patch tested?

unit test in `CollectionFunctionsSuite` and `DataFrameFunctionsSuite`.

Author: Daoyuan Wang <daoyuan.wang@intel.com>

Closes #14991 from adrian-wang/size.
2016-09-07 13:01:27 +02:00
Liwei Lin 3ce3a282c8 [SPARK-17359][SQL][MLLIB] Use ArrayBuffer.+=(A) instead of ArrayBuffer.append(A) in performance critical paths
## What changes were proposed in this pull request?

We should generally use `ArrayBuffer.+=(A)` rather than `ArrayBuffer.append(A)`, because `append(A)` would involve extra boxing / unboxing.

## How was this patch tested?

N/A

Author: Liwei Lin <lwlin7@gmail.com>

Closes #14914 from lw-lin/append_to_plus_eq_v2.
2016-09-07 10:04:00 +01:00
Tathagata Das eb1ab88a86 [SPARK-17372][SQL][STREAMING] Avoid serialization issues by using Arrays to save file names in FileStreamSource
## What changes were proposed in this pull request?

When we create a filestream on a directory that has partitioned subdirs (i.e. dir/x=y/), then ListingFileCatalog.allFiles returns the files in the dir as Seq[String] which internally is a Stream[String]. This is because of this [line](https://github.com/apache/spark/blob/master/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/PartitioningAwareFileCatalog.scala#L93), where a LinkedHashSet.values.toSeq returns Stream. Then when the [FileStreamSource](https://github.com/apache/spark/blob/master/sql/core/src/main/scala/org/apache/spark/sql/execution/streaming/FileStreamSource.scala#L79) filters this Stream[String] to remove the seen files, it creates a new Stream[String], which has a filter function that has a $outer reference to the FileStreamSource (in Scala 2.10). Trying to serialize this Stream[String] causes NotSerializableException. This will happened even if there is just one file in the dir.

Its important to note that this behavior is different in Scala 2.11. There is no $outer reference to FileStreamSource, so it does not throw NotSerializableException. However, with a large sequence of files (tested with 10000 files), it throws StackOverflowError. This is because how Stream class is implemented. Its basically like a linked list, and attempting to serialize a long Stream requires *recursively* going through linked list, thus resulting in StackOverflowError.

In short, across both Scala 2.10 and 2.11, serialization fails when both the following conditions are true.
- file stream defined on a partitioned directory
- directory has 10k+ files

The right solution is to convert the seq to an array before writing to the log. This PR implements this fix in two ways.
- Changing all uses for HDFSMetadataLog to ensure Array is used instead of Seq
- Added a `require` in HDFSMetadataLog such that it is never used with type Seq

## How was this patch tested?

Added unit test that test that ensures the file stream source can handle with 10000 files. This tests fails in both Scala 2.10 and 2.11 with different failures as indicated above.

Author: Tathagata Das <tathagata.das1565@gmail.com>

Closes #14987 from tdas/SPARK-17372.
2016-09-06 19:34:11 -07:00
Wenchen Fan d6eede9a36 [SPARK-17238][SQL] simplify the logic for converting data source table into hive compatible format
## What changes were proposed in this pull request?

Previously we have 2 conditions to decide whether a data source table is hive-compatible:

1. the data source is file-based and has a corresponding Hive serde
2. have a `path` entry in data source options/storage properties

However, if condition 1 is true, condition 2 must be true too, as we will put the default table path into data source options/storage properties for managed data source tables.

There is also a potential issue: we will set the `locationUri` even for managed table.

This PR removes the condition 2 and only set the `locationUri` for external data source tables.

Note: this is also a first step to unify the `path` of data source tables and `locationUri` of hive serde tables. For hive serde tables, `locationUri` is only set for external table. For data source tables, `path` is always set. We can make them consistent after this PR.

## How was this patch tested?

existing tests

Author: Wenchen Fan <wenchen@databricks.com>

Closes #14809 from cloud-fan/minor2.
2016-09-07 09:36:53 +08:00
gatorsmile a40657bfd3 [SPARK-17408][TEST] Flaky test: org.apache.spark.sql.hive.StatisticsSuite
### What changes were proposed in this pull request?
https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder/64956/testReport/junit/org.apache.spark.sql.hive/StatisticsSuite/test_statistics_of_LogicalRelation_converted_from_MetastoreRelation/
```
org.apache.spark.sql.hive.StatisticsSuite.test statistics of LogicalRelation converted from MetastoreRelation

Failing for the past 1 build (Since Failed#64956 )
Took 1.4 sec.
Error Message

org.scalatest.exceptions.TestFailedException: 6871 did not equal 4236
Stacktrace

sbt.ForkMain$ForkError: org.scalatest.exceptions.TestFailedException: 6871 did not equal 4236
	at org.scalatest.Assertions$class.newAssertionFailedException(Assertions.scala:500)
```

This fix does not check the exact value of `sizeInBytes`. Instead, we compare whether it is larger than zero and compare the values between different values.

In addition, we also combine `checkMetastoreRelationStats` and `checkLogicalRelationStats` into the same checking function.

### How was this patch tested?
N/A

Author: gatorsmile <gatorsmile@gmail.com>

Closes #14978 from gatorsmile/spark17408.
2016-09-07 08:13:12 +08:00
Herman van Hovell 4f769b903b [SPARK-17296][SQL] Simplify parser join processing.
## What changes were proposed in this pull request?
Join processing in the parser relies on the fact that the grammar produces a right nested trees, for instance the parse tree for `select * from a join b join c` is expected to produce a tree similar to `JOIN(a, JOIN(b, c))`. However there are cases in which this (invariant) is violated, like:
```sql
SELECT COUNT(1)
FROM test T1
     CROSS JOIN test T2
     JOIN test T3
      ON T3.col = T1.col
     JOIN test T4
      ON T4.col = T1.col
```
In this case the parser returns a tree in which Joins are located on both the left and the right sides of the parent join node.

This PR introduces a different grammar rule which does not make this assumption. The new rule takes a relation and searches for zero or more joined relations. As a bonus processing is much easier.

## How was this patch tested?
Existing tests and I have added a regression test to the plan parser suite.

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

Closes #14867 from hvanhovell/SPARK-17296.
2016-09-07 00:44:07 +02:00
Davies Liu f7e26d7887 [SPARK-16922] [SPARK-17211] [SQL] make the address of values portable in LongToUnsafeRowMap
## What changes were proposed in this pull request?

In LongToUnsafeRowMap, we use offset of a value as pointer, stored in a array also in the page for chained values. The offset is not portable, because Platform.LONG_ARRAY_OFFSET will be different with different JVM Heap size, then the deserialized LongToUnsafeRowMap will be corrupt.

This PR will change to use portable address (without Platform.LONG_ARRAY_OFFSET).

## How was this patch tested?

Added a test case with random generated keys, to improve the coverage. But this test is not a regression test, that could require a Spark cluster that have at least 32G heap in driver or executor.

Author: Davies Liu <davies@databricks.com>

Closes #14927 from davies/longmap.
2016-09-06 10:46:31 -07:00
Sean Zhong bc2767df26 [SPARK-17374][SQL] Better error messages when parsing JSON using DataFrameReader
## What changes were proposed in this pull request?

This PR adds better error messages for malformed record when reading a JSON file using DataFrameReader.

For example, for query:
```
import org.apache.spark.sql.types._
val corruptRecords = spark.sparkContext.parallelize("""{"a":{, b:3}""" :: Nil)
val schema = StructType(StructField("a", StringType, true) :: Nil)
val jsonDF = spark.read.schema(schema).json(corruptRecords)
```

**Before change:**
We silently replace corrupted line with null
```
scala> jsonDF.show
+----+
|   a|
+----+
|null|
+----+
```

**After change:**
Add an explicit warning message:
```
scala> jsonDF.show
16/09/02 14:43:16 WARN JacksonParser: Found at least one malformed records (sample: {"a":{, b:3}). The JSON reader will replace
all malformed records with placeholder null in current PERMISSIVE parser mode.
To find out which corrupted records have been replaced with null, please use the
default inferred schema instead of providing a custom schema.

Code example to print all malformed records (scala):
===================================================
// The corrupted record exists in column _corrupt_record.
val parsedJson = spark.read.json("/path/to/json/file/test.json")

+----+
|   a|
+----+
|null|
+----+
```

###

## How was this patch tested?

Unit test.

Author: Sean Zhong <seanzhong@databricks.com>

Closes #14929 from clockfly/logwarning_if_schema_not_contain_corrupted_record.
2016-09-06 22:20:55 +08:00
Sean Zhong 6f13aa7dfe [SPARK-17356][SQL] Fix out of memory issue when generating JSON for TreeNode
## What changes were proposed in this pull request?

class `org.apache.spark.sql.types.Metadata` is widely used in mllib to store some ml attributes. `Metadata` is commonly stored in `Alias` expression.

```
case class Alias(child: Expression, name: String)(
    val exprId: ExprId = NamedExpression.newExprId,
    val qualifier: Option[String] = None,
    val explicitMetadata: Option[Metadata] = None,
    override val isGenerated: java.lang.Boolean = false)
```

The `Metadata` can take a big memory footprint since the number of attributes is big ( in scale of million). When `toJSON` is called on `Alias` expression, the `Metadata` will also be converted to a big JSON string.
If a plan contains many such kind of `Alias` expressions, it may trigger out of memory error when `toJSON` is called, since converting all `Metadata` references to JSON will take huge memory.

With this PR, we will skip scanning Metadata when doing JSON conversion. For a reproducer of the OOM, and analysis, please look at jira https://issues.apache.org/jira/browse/SPARK-17356.

## How was this patch tested?

Existing tests.

Author: Sean Zhong <seanzhong@databricks.com>

Closes #14915 from clockfly/json_oom.
2016-09-06 16:05:50 +08:00
Wenchen Fan c0ae6bc6ea [SPARK-17361][SQL] file-based external table without path should not be created
## What changes were proposed in this pull request?

Using the public `Catalog` API, users can create a file-based data source table, without giving the path options. For this case, currently we can create the table successfully, but fail when we read it. Ideally we should fail during creation.

This is because when we create data source table, we resolve the data source relation without validating path: `resolveRelation(checkPathExist = false)`.

Looking back to why we add this trick(`checkPathExist`), it's because when we call `resolveRelation` for managed table, we add the path to data source options but the path is not created yet. So why we add this not-yet-created path to data source options? This PR fix the problem by adding path to options after we call `resolveRelation`. Then we can remove the `checkPathExist` parameter in `DataSource.resolveRelation` and do some related cleanups.

## How was this patch tested?

existing tests and new test in `CatalogSuite`

Author: Wenchen Fan <wenchen@databricks.com>

Closes #14921 from cloud-fan/check-path.
2016-09-06 14:17:47 +08:00
Yadong Qi 64e826f91e [SPARK-17358][SQL] Cached table(parquet/orc) should be shard between beelines
## What changes were proposed in this pull request?
Cached table(parquet/orc) couldn't be shard between beelines, because the `sameResult` method used by `CacheManager` always return false(`sparkSession` are different) when compare two `HadoopFsRelation` in different beelines. So we make `sparkSession` a curry parameter.

## How was this patch tested?
Beeline1
```
1: jdbc:hive2://localhost:10000> CACHE TABLE src_pqt;
+---------+--+
| Result  |
+---------+--+
+---------+--+
No rows selected (5.143 seconds)
1: jdbc:hive2://localhost:10000> EXPLAIN SELECT * FROM src_pqt;
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--+
|                                                                                                                                                                                                            plan                                                                                                                                                                                                            |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--+
| == Physical Plan ==
InMemoryTableScan [key#49, value#50]
   +- InMemoryRelation [key#49, value#50], true, 10000, StorageLevel(disk, memory, deserialized, 1 replicas), `src_pqt`
         +- *FileScan parquet default.src_pqt[key#0,value#1] Batched: true, Format: ParquetFormat, InputPaths: hdfs://199.0.0.1:9000/qiyadong/src_pqt, PartitionFilters: [], PushedFilters: [], ReadSchema: struct<key:int,value:string>  |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--+
```

Beeline2
```
0: jdbc:hive2://localhost:10000> EXPLAIN SELECT * FROM src_pqt;
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--+
|                                                                                                                                                                                                            plan                                                                                                                                                                                                            |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--+
| == Physical Plan ==
InMemoryTableScan [key#68, value#69]
   +- InMemoryRelation [key#68, value#69], true, 10000, StorageLevel(disk, memory, deserialized, 1 replicas), `src_pqt`
         +- *FileScan parquet default.src_pqt[key#0,value#1] Batched: true, Format: ParquetFormat, InputPaths: hdfs://199.0.0.1:9000/qiyadong/src_pqt, PartitionFilters: [], PushedFilters: [], ReadSchema: struct<key:int,value:string>  |
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+--+
```

Author: Yadong Qi <qiyadong2010@gmail.com>

Closes #14913 from watermen/SPARK-17358.
2016-09-06 10:57:21 +08:00
Sean Zhong afb3d5d301 [SPARK-17369][SQL] MetastoreRelation toJSON throws AssertException due to missing otherCopyArgs
## What changes were proposed in this pull request?

`TreeNode.toJSON` requires a subclass to explicitly override otherCopyArgs to include currying construction arguments, otherwise it reports AssertException telling that the construction argument values' count doesn't match the construction argument names' count.

For class `MetastoreRelation`, it has a currying construction parameter `client: HiveClient`, but Spark forgets to add it to the list of otherCopyArgs.

## How was this patch tested?

Unit tests.

Author: Sean Zhong <seanzhong@databricks.com>

Closes #14928 from clockfly/metastore_relation_toJSON.
2016-09-06 10:50:07 +08:00
Wenchen Fan 8d08f43d09 [SPARK-17279][SQL] better error message for exceptions during ScalaUDF execution
## What changes were proposed in this pull request?

If `ScalaUDF` throws exceptions during executing user code, sometimes it's hard for users to figure out what's wrong, especially when they use Spark shell. An example
```
org.apache.spark.SparkException: Job aborted due to stage failure: Task 12 in stage 325.0 failed 4 times, most recent failure: Lost task 12.3 in stage 325.0 (TID 35622, 10.0.207.202): java.lang.NullPointerException
	at line8414e872fb8b42aba390efc153d1611a12.$read$$iwC$$iwC$$iwC$$iwC$$anonfun$2.apply(<console>:40)
	at line8414e872fb8b42aba390efc153d1611a12.$read$$iwC$$iwC$$iwC$$iwC$$anonfun$2.apply(<console>:40)
	at org.apache.spark.sql.catalyst.expressions.GeneratedClass$GeneratedIterator.processNext(Unknown Source)
...
```
We should catch these exceptions and rethrow them with better error message, to say that the exception is happened in scala udf.

This PR also does some clean up for `ScalaUDF` and add a unit test suite for it.

## How was this patch tested?

the new test suite

Author: Wenchen Fan <wenchen@databricks.com>

Closes #14850 from cloud-fan/npe.
2016-09-06 10:36:00 +08:00
wangzhenhua 6d86403d8b [SPARK-17072][SQL] support table-level statistics generation and storing into/loading from metastore
## What changes were proposed in this pull request?

1. Support generation table-level statistics for
    - hive tables in HiveExternalCatalog
    - data source tables in HiveExternalCatalog
    - data source tables in InMemoryCatalog.
2. Add a property "catalogStats" in CatalogTable to hold statistics in Spark side.
3. Put logics of statistics transformation between Spark and Hive in HiveClientImpl.
4. Extend Statistics class by adding rowCount (will add estimatedSize when we have column stats).

## How was this patch tested?

add unit tests

Author: wangzhenhua <wangzhenhua@huawei.com>
Author: Zhenhua Wang <wangzhenhua@huawei.com>

Closes #14712 from wzhfy/tableStats.
2016-09-05 17:32:31 +02:00
Wenchen Fan 3ccb23e445 [SPARK-17394][SQL] should not allow specify database in table/view name after RENAME TO
## What changes were proposed in this pull request?

It's really weird that we allow users to specify database in both from table name and to table name
 in `ALTER TABLE RENAME TO`, while logically we can't support rename a table to a different database.

Both postgres and MySQL disallow this syntax, it's reasonable to follow them and simply our code.

## How was this patch tested?

new test in `DDLCommandSuite`

Author: Wenchen Fan <wenchen@databricks.com>

Closes #14955 from cloud-fan/rename.
2016-09-05 13:09:20 +08:00
gatorsmile c1e9a6d274 [SPARK-17393][SQL] Error Handling when CTAS Against the Same Data Source Table Using Overwrite Mode
### What changes were proposed in this pull request?
When we trying to read a table and then write to the same table using the `Overwrite` save mode, we got a very confusing error message:
For example,
```Scala
      Seq((1, 2)).toDF("i", "j").write.saveAsTable("tab1")
      table("tab1").write.mode(SaveMode.Overwrite).saveAsTable("tab1")
```

```
Job aborted.
org.apache.spark.SparkException: Job aborted.
	at org.apache.spark.sql.execution.datasources.InsertIntoHadoopFsRelationCommand$$anonfun$run$1.apply$mcV$sp
...
Caused by: org.apache.spark.SparkException: Task failed while writing rows
	at org.apache.spark.sql.execution.datasources.DefaultWriterContainer.writeRows(WriterContainer.scala:266)
	at org.apache.spark.sql.execution.datasources.InsertIntoHadoopFsRelationCommand$$anonfun$run$1$$anonfun$apply$mcV$sp$1.apply(InsertIntoHadoopFsRelationCommand.scala:143)
	at org.apache.spark.sql.execution.datasources
```

After the PR, we will issue an `AnalysisException`:
```
Cannot overwrite table `tab1` that is also being read from
```
### How was this patch tested?
Added test cases.

Author: gatorsmile <gatorsmile@gmail.com>

Closes #14954 from gatorsmile/ctasQueryAnalyze.
2016-09-05 11:28:19 +08:00
Shivansh e75c162e9e [SPARK-17308] Improved the spark core code by replacing all pattern match on boolean value by if/else block.
## What changes were proposed in this pull request?
Improved the code quality of spark by replacing all pattern match on boolean value by if/else block.

## How was this patch tested?

By running the tests

Author: Shivansh <shiv4nsh@gmail.com>

Closes #14873 from shiv4nsh/SPARK-17308.
2016-09-04 12:39:26 +01:00
gatorsmile 6b156e2fcf [SPARK-17324][SQL] Remove Direct Usage of HiveClient in InsertIntoHiveTable
### What changes were proposed in this pull request?
This is another step to get rid of HiveClient from `HiveSessionState`. All the metastore interactions should be through `ExternalCatalog` interface. However, the existing implementation of `InsertIntoHiveTable ` still requires Hive clients. This PR is to remove HiveClient by moving the metastore interactions into `ExternalCatalog`.

### How was this patch tested?
Existing test cases

Author: gatorsmile <gatorsmile@gmail.com>

Closes #14888 from gatorsmile/removeClientFromInsertIntoHiveTable.
2016-09-04 15:04:33 +08:00
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