Commit graph

1321 commits

Author SHA1 Message Date
Sameer Agarwal 926e9c45a2 [SPARK-13760][SQL] Fix BigDecimal constructor for FloatType
## What changes were proposed in this pull request?

A very minor change for using `BigDecimal.decimal(f: Float)` instead of `BigDecimal(f: float)`. The latter is deprecated and can result in inconsistencies due to an implicit conversion to `Double`.

## How was this patch tested?

N/A

cc yhuai

Author: Sameer Agarwal <sameer@databricks.com>

Closes #11597 from sameeragarwal/bigdecimal.
2016-03-09 18:16:29 -08:00
Sameer Agarwal dbf2a7cfad [SPARK-13781][SQL] Use ExpressionSets in ConstraintPropagationSuite
## What changes were proposed in this pull request?

This PR is a small follow up on https://github.com/apache/spark/pull/11338 (https://issues.apache.org/jira/browse/SPARK-13092) to use `ExpressionSet` as part of the verification logic in `ConstraintPropagationSuite`.
## How was this patch tested?

No new tests added. Just changes the verification logic in `ConstraintPropagationSuite`.

Author: Sameer Agarwal <sameer@databricks.com>

Closes #11611 from sameeragarwal/expression-set.
2016-03-09 15:27:18 -08:00
gatorsmile c6aa356cd8 [SPARK-13527][SQL] Prune Filters based on Constraints
#### What changes were proposed in this pull request?

Remove all the deterministic conditions in a [[Filter]] that are contained in the Child's Constraints.

For example, the first query can be simplified to the second one.

```scala
    val queryWithUselessFilter = tr1
      .where("tr1.a".attr > 10 || "tr1.c".attr < 10)
      .join(tr2.where('d.attr < 100), Inner, Some("tr1.a".attr === "tr2.a".attr))
      .where(
        ("tr1.a".attr > 10 || "tr1.c".attr < 10) &&
        'd.attr < 100 &&
        "tr2.a".attr === "tr1.a".attr)
```
```scala
    val query = tr1
      .where("tr1.a".attr > 10 || "tr1.c".attr < 10)
      .join(tr2.where('d.attr < 100), Inner, Some("tr1.a".attr === "tr2.a".attr))
```
#### How was this patch tested?

Six test cases are added.

Author: gatorsmile <gatorsmile@gmail.com>

Closes #11406 from gatorsmile/FilterRemoval.
2016-03-09 12:50:55 -08:00
Davies Liu 3dc9ae2e15 [SPARK-13523] [SQL] Reuse exchanges in a query
## What changes were proposed in this pull request?

It’s possible to have common parts in a query, for example, self join, it will be good to avoid the duplicated part to same CPUs and memory (Broadcast or cache).

Exchange will materialize the underlying RDD by shuffle or collect, it’s a great point to check duplicates and reuse them. Duplicated exchanges means they generate exactly the same result inside a query.

In order to find out the duplicated exchanges, we should be able to compare SparkPlan to check that they have same results or not. We already have that for LogicalPlan, so we should move that into QueryPlan to make it available for SparkPlan.

Once we can find the duplicated exchanges, we should replace all of them with same SparkPlan object (could be wrapped by ReusedExchage for explain), then the plan tree become a DAG. Since all the planner only work with tree, so this rule should be the last one for the entire planning.

After the rule, the plan will looks like:

```
WholeStageCodegen
:  +- Project [id#0L]
:     +- BroadcastHashJoin [id#0L], [id#2L], Inner, BuildRight, None
:        :- Project [id#0L]
:        :  +- BroadcastHashJoin [id#0L], [id#1L], Inner, BuildRight, None
:        :     :- Range 0, 1, 4, 1024, [id#0L]
:        :     +- INPUT
:        +- INPUT
:- BroadcastExchange HashedRelationBroadcastMode(true,List(id#1L),List(id#1L))
:  +- WholeStageCodegen
:     :  +- Range 0, 1, 4, 1024, [id#1L]
+- ReusedExchange [id#2L], BroadcastExchange HashedRelationBroadcastMode(true,List(id#1L),List(id#1L))
```

![bjoin](https://cloud.githubusercontent.com/assets/40902/13414787/209e8c5c-df0a-11e5-8a0f-edff69d89e83.png)

For three ways SortMergeJoin,
```
== Physical Plan ==
WholeStageCodegen
:  +- Project [id#0L]
:     +- SortMergeJoin [id#0L], [id#4L], None
:        :- INPUT
:        +- INPUT
:- WholeStageCodegen
:  :  +- Project [id#0L]
:  :     +- SortMergeJoin [id#0L], [id#3L], None
:  :        :- INPUT
:  :        +- INPUT
:  :- WholeStageCodegen
:  :  :  +- Sort [id#0L ASC], false, 0
:  :  :     +- INPUT
:  :  +- Exchange hashpartitioning(id#0L, 200), None
:  :     +- WholeStageCodegen
:  :        :  +- Range 0, 1, 4, 33554432, [id#0L]
:  +- WholeStageCodegen
:     :  +- Sort [id#3L ASC], false, 0
:     :     +- INPUT
:     +- ReusedExchange [id#3L], Exchange hashpartitioning(id#0L, 200), None
+- WholeStageCodegen
   :  +- Sort [id#4L ASC], false, 0
   :     +- INPUT
   +- ReusedExchange [id#4L], Exchange hashpartitioning(id#0L, 200), None
```
![sjoin](https://cloud.githubusercontent.com/assets/40902/13414790/27aea61c-df0a-11e5-8cbf-fbc985c31d95.png)

If the same ShuffleExchange or BroadcastExchange, execute()/executeBroadcast() will be called by different parents, they should cached the RDD/Broadcast, return the same one for all the parents.

## How was this patch tested?

Added some unit tests for this.  Had done some manual tests on TPCDS query Q59 and Q64, we can see some exchanges are re-used (this requires a change in PhysicalRDD to for sameResult, is be done in #11514 ).

Author: Davies Liu <davies@databricks.com>

Closes #11403 from davies/dedup.
2016-03-09 12:04:29 -08:00
gatorsmile 23369c3bd2 [SPARK-13763][SQL] Remove Project when its Child's Output is Nil
#### What changes were proposed in this pull request?

As shown in another PR: https://github.com/apache/spark/pull/11596, we are using `SELECT 1` as a dummy table, when the table is used for SQL statements in which a table reference is required, but the contents of the table are not important. For example,

```SQL
SELECT value FROM (select 1) dummyTable Lateral View explode(array(1,2,3)) adTable as value
```
Before the PR, the optimized plan contains a useless `Project` after Optimizer executing the `ColumnPruning` rule, as shown below:

```
== Analyzed Logical Plan ==
value: int
Project [value#22]
+- Generate explode(array(1, 2, 3)), true, false, Some(adtable), [value#22]
   +- SubqueryAlias dummyTable
      +- Project [1 AS 1#21]
         +- OneRowRelation$

== Optimized Logical Plan ==
Generate explode([1,2,3]), false, false, Some(adtable), [value#22]
+- Project
   +- OneRowRelation$
```

After the fix, the optimized plan removed the useless `Project`, as shown below:
```
== Optimized Logical Plan ==
Generate explode([1,2,3]), false, false, Some(adtable), [value#22]
+- OneRowRelation$
```

This PR is to remove `Project` when its Child's output is Nil

#### How was this patch tested?

Added a new unit test case into the suite `ColumnPruningSuite.scala`

Author: gatorsmile <gatorsmile@gmail.com>

Closes #11599 from gatorsmile/projectOneRowRelation.
2016-03-09 10:29:27 -08:00
Davies Liu 7791d0c3a9 Revert "[SPARK-13668][SQL] Reorder filter/join predicates to short-circuit isNotNull checks"
This reverts commit e430614eae.
2016-03-09 10:05:57 -08:00
Davies Liu 9634e17d01 [SPARK-13242] [SQL] codegen fallback in case-when if there many branches
## What changes were proposed in this pull request?

If there are many branches in a CaseWhen expression, the generated code could go above the 64K limit for single java method, will fail to compile. This PR change it to fallback to interpret mode if there are more than 20 branches.

This PR is based on #11243 and #11221, thanks to joehalliwell

Closes #11243
Closes #11221

## How was this patch tested?

Add a test with 50 branches.

Author: Davies Liu <davies@databricks.com>

Closes #11592 from davies/fix_when.
2016-03-09 09:27:28 -08:00
Dilip Biswal 53ba6d6e59 [SPARK-13698][SQL] Fix Analysis Exceptions when Using Backticks in Generate
## What changes were proposed in this pull request?
Analysis exception occurs while running the following query.
```
SELECT ints FROM nestedArray LATERAL VIEW explode(a.b) `a` AS `ints`
```
```
Failed to analyze query: org.apache.spark.sql.AnalysisException: cannot resolve '`ints`' given input columns: [a, `ints`]; line 1 pos 7
'Project ['ints]
+- Generate explode(a#0.b), true, false, Some(a), [`ints`#8]
   +- SubqueryAlias nestedarray
      +- LocalRelation [a#0], [[[[1,2,3]]]]
```

## How was this patch tested?

Added new unit tests in SQLQuerySuite and HiveQlSuite

Author: Dilip Biswal <dbiswal@us.ibm.com>

Closes #11538 from dilipbiswal/SPARK-13698.
2016-03-09 21:49:37 +08:00
Dongjoon Hyun c3689bc24e [SPARK-13702][CORE][SQL][MLLIB] Use diamond operator for generic instance creation in Java code.
## What changes were proposed in this pull request?

In order to make `docs/examples` (and other related code) more simple/readable/user-friendly, this PR replaces existing codes like the followings by using `diamond` operator.

```
-    final ArrayList<Product2<Object, Object>> dataToWrite =
-      new ArrayList<Product2<Object, Object>>();
+    final ArrayList<Product2<Object, Object>> dataToWrite = new ArrayList<>();
```

Java 7 or higher supports **diamond** operator which replaces the type arguments required to invoke the constructor of a generic class with an empty set of type parameters (<>). Currently, Spark Java code use mixed usage of this.

## How was this patch tested?

Manual.
Pass the existing tests.

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #11541 from dongjoon-hyun/SPARK-13702.
2016-03-09 10:31:26 +00:00
Takuya UESHIN 2c5af7d4d9 [SPARK-13640][SQL] Synchronize ScalaReflection.mirror method.
## What changes were proposed in this pull request?

`ScalaReflection.mirror` method should be synchronized when scala version is `2.10` because `universe.runtimeMirror` is not thread safe.

## How was this patch tested?

I added a test to check thread safety of `ScalaRefection.mirror` method in `ScalaReflectionSuite`, which will throw the following Exception in Scala `2.10` without this patch:

```
[info] - thread safety of mirror *** FAILED *** (49 milliseconds)
[info]   java.lang.UnsupportedOperationException: tail of empty list
[info]   at scala.collection.immutable.Nil$.tail(List.scala:339)
[info]   at scala.collection.immutable.Nil$.tail(List.scala:334)
[info]   at scala.reflect.internal.SymbolTable.popPhase(SymbolTable.scala:172)
[info]   at scala.reflect.internal.Symbols$Symbol.unsafeTypeParams(Symbols.scala:1477)
[info]   at scala.reflect.internal.Symbols$TypeSymbol.tpe(Symbols.scala:2777)
[info]   at scala.reflect.internal.Mirrors$RootsBase.init(Mirrors.scala:235)
[info]   at scala.reflect.runtime.JavaMirrors$class.createMirror(JavaMirrors.scala:34)
[info]   at scala.reflect.runtime.JavaMirrors$class.runtimeMirror(JavaMirrors.scala:61)
[info]   at scala.reflect.runtime.JavaUniverse.runtimeMirror(JavaUniverse.scala:12)
[info]   at scala.reflect.runtime.JavaUniverse.runtimeMirror(JavaUniverse.scala:12)
[info]   at org.apache.spark.sql.catalyst.ScalaReflection$.mirror(ScalaReflection.scala:36)
[info]   at org.apache.spark.sql.catalyst.ScalaReflectionSuite$$anonfun$12$$anonfun$apply$mcV$sp$1$$anonfun$apply$1$$anonfun$apply$2.apply(ScalaReflectionSuite.scala:256)
[info]   at org.apache.spark.sql.catalyst.ScalaReflectionSuite$$anonfun$12$$anonfun$apply$mcV$sp$1$$anonfun$apply$1$$anonfun$apply$2.apply(ScalaReflectionSuite.scala:252)
[info]   at scala.concurrent.impl.Future$PromiseCompletingRunnable.liftedTree1$1(Future.scala:24)
[info]   at scala.concurrent.impl.Future$PromiseCompletingRunnable.run(Future.scala:24)
[info]   at scala.concurrent.impl.ExecutionContextImpl$$anon$3.exec(ExecutionContextImpl.scala:107)
[info]   at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
[info]   at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
[info]   at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
[info]   at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
```

Notice that the test will pass when Scala version is `2.11`.

Author: Takuya UESHIN <ueshin@happy-camper.st>

Closes #11487 from ueshin/issues/SPARK-13640.
2016-03-09 10:23:27 +00:00
Jakob Odersky 035d3acdf3 [SPARK-7286][SQL] Deprecate !== in favour of =!=
This PR replaces #9925 which had issues with CI. **Please see the original PR for any previous discussions.**

## What changes were proposed in this pull request?
Deprecate the SparkSQL column operator !== and use =!= as an alternative.
Fixes subtle issues related to operator precedence (basically, !== does not have the same priority as its logical negation, ===).

## How was this patch tested?
All currently existing tests.

Author: Jakob Odersky <jodersky@gmail.com>

Closes #11588 from jodersky/SPARK-7286.
2016-03-08 18:11:09 -08:00
Sameer Agarwal e430614eae [SPARK-13668][SQL] Reorder filter/join predicates to short-circuit isNotNull checks
## What changes were proposed in this pull request?

If a filter predicate or a join condition consists of `IsNotNull` checks, we should reorder these checks such that these non-nullability checks are evaluated before the rest of the predicates.

For e.g., if a filter predicate is of the form `a > 5 && isNotNull(b)`, we should rewrite this as `isNotNull(b) && a > 5` during physical plan generation.

## How was this patch tested?

new unit tests that verify the physical plan for both filters and joins in `ReorderedPredicateSuite`

Author: Sameer Agarwal <sameer@databricks.com>

Closes #11511 from sameeragarwal/reorder-isnotnull.
2016-03-08 15:40:45 -08:00
Dongjoon Hyun 076009b949 [SPARK-13400] Stop using deprecated Octal escape literals
## What changes were proposed in this pull request?

This removes the remaining deprecated Octal escape literals. The followings are the warnings on those two lines.
```
LiteralExpressionSuite.scala:99: Octal escape literals are deprecated, use \u0000 instead.
HiveQlSuite.scala:74: Octal escape literals are deprecated, use \u002c instead.
```

## How was this patch tested?

Manual.
During building, there should be no warning on `Octal escape literals`.
```
mvn -DskipTests clean install
```

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #11584 from dongjoon-hyun/SPARK-13400.
2016-03-08 15:00:26 -08:00
Wenchen Fan 46881b4ea2 [SPARK-12727][SQL] support SQL generation for aggregate with multi-distinct
## What changes were proposed in this pull request?

This PR add SQL generation support for aggregate with multi-distinct, by simply moving the `DistinctAggregationRewriter` rule to optimizer.

More discussions are needed as this breaks an import contract: analyzed plan should be able to run without optimization.  However, the `ComputeCurrentTime` rule has kind of broken it already, and I think maybe we should add a new phase for this kind of rules, because strictly speaking they don't belong to analysis and is coupled with the physical plan implementation.

## How was this patch tested?

existing tests

Author: Wenchen Fan <wenchen@databricks.com>

Closes #11579 from cloud-fan/distinct.
2016-03-08 11:45:08 -08:00
Davies Liu 78d3b6051e [SPARK-13657] [SQL] Support parsing very long AND/OR expressions
## What changes were proposed in this pull request?

In order to avoid StackOverflow when parse a expression with hundreds of ORs, we should use loop instead of recursive functions to flatten the tree as list. This PR also build a balanced tree to reduce the depth of generated And/Or expression, to avoid StackOverflow in analyzer/optimizer.

## How was this patch tested?

Add new unit tests. Manually tested with TPCDS Q3 with hundreds predicates in it [1]. These predicates help to reduce the number of partitions, then the query time went from 60 seconds to 8 seconds.

[1] https://github.com/cloudera/impala-tpcds-kit/blob/master/queries/q3.sql

Author: Davies Liu <davies@databricks.com>

Closes #11501 from davies/long_or.
2016-03-08 10:23:19 -08:00
Wenchen Fan 7d05d02bff [SPARK-13637][SQL] use more information to simplify the code in Expand builder
## What changes were proposed in this pull request?

The code in `Expand.apply` can be simplified by existing information:

* the `groupByExprs` parameter are all `Attribute`s
* the `child` parameter is a `Project` that append aliased group by expressions to its child's output

## How was this patch tested?

by existing tests.

Author: Wenchen Fan <wenchen@databricks.com>

Closes #11485 from cloud-fan/expand.
2016-03-08 23:34:42 +08:00
Davies Liu 25bba58d16 [SPARK-13404] [SQL] Create variables for input row when it's actually used
## What changes were proposed in this pull request?

This PR change the way how we generate the code for the output variables passing from a plan to it's parent.

Right now, they are generated before call consume() of it's parent. It's not efficient, if the parent is a Filter or Join, which could filter out most the rows, the time to access some of the columns that are not used by the Filter or Join are wasted.

This PR try to improve this by defering the access of columns until they are actually used by a plan. After this PR, a plan does not need to generate code to evaluate the variables for output, just passing the ExprCode to its parent by `consume()`. In `parent.consumeChild()`, it will check the output from child and `usedInputs`, generate the code for those columns that is part of `usedInputs` before calling `doConsume()`.

This PR also change the `if` from
```
if (cond) {
  xxx
}
```
to
```
if (!cond) continue;
xxx
```
The new one could help to reduce the nested indents for multiple levels of Filter and BroadcastHashJoin.

It also added some comments for operators.

## How was the this patch tested?

Unit tests. Manually ran TPCDS Q55, this PR improve the performance about 30% (scale=10, from 2.56s to 1.96s)

Author: Davies Liu <davies@databricks.com>

Closes #11274 from davies/gen_defer.
2016-03-07 20:09:08 -08:00
Andrew Or da7bfac488 [SPARK-13689][SQL] Move helper things in CatalystQl to new utils object
## What changes were proposed in this pull request?

When we add more DDL parsing logic in the future, SparkQl will become very big. To keep it smaller, we'll introduce helper "parser objects", e.g. one to parse alter table commands. However, these parser objects will need to access some helper methods that exist in CatalystQl. The proposal is to move those methods to an isolated ParserUtils object.

This is based on viirya's changes in #11048. It prefaces the bigger fix for SPARK-13139 to make the diff of that patch smaller.

## How was this patch tested?

No change in functionality, so just Jenkins.

Author: Andrew Or <andrew@databricks.com>

Closes #11529 from andrewor14/parser-utils.
2016-03-07 18:01:27 -08:00
Michael Armbrust e720dda42e [SPARK-13665][SQL] Separate the concerns of HadoopFsRelation
`HadoopFsRelation` is used for reading most files into Spark SQL.  However today this class mixes the concerns of file management, schema reconciliation, scan building, bucketing, partitioning, and writing data.  As a result, many data sources are forced to reimplement the same functionality and the various layers have accumulated a fair bit of inefficiency.  This PR is a first cut at separating this into several components / interfaces that are each described below.  Additionally, all implementations inside of Spark (parquet, csv, json, text, orc, svmlib) have been ported to the new API `FileFormat`.  External libraries, such as spark-avro will also need to be ported to work with Spark 2.0.

### HadoopFsRelation
A simple `case class` that acts as a container for all of the metadata required to read from a datasource.  All discovery, resolution and merging logic for schemas and partitions has been removed.  This an internal representation that no longer needs to be exposed to developers.

```scala
case class HadoopFsRelation(
    sqlContext: SQLContext,
    location: FileCatalog,
    partitionSchema: StructType,
    dataSchema: StructType,
    bucketSpec: Option[BucketSpec],
    fileFormat: FileFormat,
    options: Map[String, String]) extends BaseRelation
```

### FileFormat
The primary interface that will be implemented by each different format including external libraries.  Implementors are responsible for reading a given format and converting it into `InternalRow` as well as writing out an `InternalRow`.  A format can optionally return a schema that is inferred from a set of files.

```scala
trait FileFormat {
  def inferSchema(
      sqlContext: SQLContext,
      options: Map[String, String],
      files: Seq[FileStatus]): Option[StructType]

  def prepareWrite(
      sqlContext: SQLContext,
      job: Job,
      options: Map[String, String],
      dataSchema: StructType): OutputWriterFactory

  def buildInternalScan(
      sqlContext: SQLContext,
      dataSchema: StructType,
      requiredColumns: Array[String],
      filters: Array[Filter],
      bucketSet: Option[BitSet],
      inputFiles: Array[FileStatus],
      broadcastedConf: Broadcast[SerializableConfiguration],
      options: Map[String, String]): RDD[InternalRow]
}
```

The current interface is based on what was required to get all the tests passing again, but still mixes a couple of concerns (i.e. `bucketSet` is passed down to the scan instead of being resolved by the planner).  Additionally, scans are still returning `RDD`s instead of iterators for single files.  In a future PR, bucketing should be removed from this interface and the scan should be isolated to a single file.

### FileCatalog
This interface is used to list the files that make up a given relation, as well as handle directory based partitioning.

```scala
trait FileCatalog {
  def paths: Seq[Path]
  def partitionSpec(schema: Option[StructType]): PartitionSpec
  def allFiles(): Seq[FileStatus]
  def getStatus(path: Path): Array[FileStatus]
  def refresh(): Unit
}
```

Currently there are two implementations:
 - `HDFSFileCatalog` - based on code from the old `HadoopFsRelation`.  Infers partitioning by recursive listing and caches this data for performance
 - `HiveFileCatalog` - based on the above, but it uses the partition spec from the Hive Metastore.

### ResolvedDataSource
Produces a logical plan given the following description of a Data Source (which can come from DataFrameReader or a metastore):
 - `paths: Seq[String] = Nil`
 - `userSpecifiedSchema: Option[StructType] = None`
 - `partitionColumns: Array[String] = Array.empty`
 - `bucketSpec: Option[BucketSpec] = None`
 - `provider: String`
 - `options: Map[String, String]`

This class is responsible for deciding which of the Data Source APIs a given provider is using (including the non-file based ones).  All reconciliation of partitions, buckets, schema from metastores or inference is done here.

### DataSourceAnalysis / DataSourceStrategy
Responsible for analyzing and planning reading/writing of data using any of the Data Source APIs, including:
 - pruning the files from partitions that will be read based on filters.
 - appending partition columns*
 - applying additional filters when a data source can not evaluate them internally.
 - constructing an RDD that is bucketed correctly when required*
 - sanity checking schema match-up and other analysis when writing.

*In the future we should do that following:
 - Break out file handling into its own Strategy as its sufficiently complex / isolated.
 - Push the appending of partition columns down in to `FileFormat` to avoid an extra copy / unvectorization.
 - Use a custom RDD for scans instead of `SQLNewNewHadoopRDD2`

Author: Michael Armbrust <michael@databricks.com>
Author: Wenchen Fan <wenchen@databricks.com>

Closes #11509 from marmbrus/fileDataSource.
2016-03-07 15:15:10 -08:00
gatorsmile b6071a7001 [SPARK-13722][SQL] No Push Down for Non-deterministics Predicates through Generate
#### What changes were proposed in this pull request?

Non-deterministic predicates should not be pushed through Generate.

#### How was this patch tested?

Added a test case in `FilterPushdownSuite.scala`

Author: gatorsmile <gatorsmile@gmail.com>

Closes #11562 from gatorsmile/pushPredicateDownWindow.
2016-03-07 12:09:27 -08:00
Sameer Agarwal ef77003178 [SPARK-13495][SQL] Add Null Filters in the query plan for Filters/Joins based on their data constraints
## What changes were proposed in this pull request?

This PR adds an optimizer rule to eliminate reading (unnecessary) NULL values if they are not required for correctness by inserting `isNotNull` filters is the query plan. These filters are currently inserted beneath existing `Filter` and `Join` operators and are inferred based on their data constraints.

Note: While this optimization is applicable to all types of join, it primarily benefits `Inner` and `LeftSemi` joins.

## How was this patch tested?

1. Added a new `NullFilteringSuite` that tests for `IsNotNull` filters in the query plan for joins and filters. Also, tests interaction with the `CombineFilters` optimizer rules.
2. Test generated ExpressionTrees via `OrcFilterSuite`
3. Test filter source pushdown logic via `SimpleTextHadoopFsRelationSuite`

cc yhuai nongli

Author: Sameer Agarwal <sameer@databricks.com>

Closes #11372 from sameeragarwal/gen-isnotnull.
2016-03-07 12:04:59 -08:00
Wenchen Fan 4896411176 [SPARK-13694][SQL] QueryPlan.expressions should always include all expressions
## What changes were proposed in this pull request?

It's weird that expressions don't always have all the expressions in it. This PR marks `QueryPlan.expressions` final to forbid sub classes overriding it to exclude some expressions. Currently only `Generate` override it, we can use `producedAttributes` to fix the unresolved attribute problem for it.

Note that this PR doesn't fix the problem in #11497

## How was this patch tested?

existing tests.

Author: Wenchen Fan <wenchen@databricks.com>

Closes #11532 from cloud-fan/generate.
2016-03-07 10:32:34 -08:00
Dilip Biswal d7eac9d795 [SPARK-13651] Generator outputs are not resolved correctly resulting in run time error
## What changes were proposed in this pull request?

```
Seq(("id1", "value1")).toDF("key", "value").registerTempTable("src")
sqlContext.sql("SELECT t1.* FROM src LATERAL VIEW explode(map('key1', 100, 'key2', 200)) t1 AS key, value")
```
Results in following logical plan

```
Project [key#2,value#3]
+- Generate explode(HiveGenericUDF#org.apache.hadoop.hive.ql.udf.generic.GenericUDFMap(key1,100,key2,200)), true, false, Some(genoutput), [key#2,value#3]
   +- SubqueryAlias src
      +- Project [_1#0 AS key#2,_2#1 AS value#3]
         +- LocalRelation [_1#0,_2#1], [[id1,value1]]
```

The above query fails with following runtime error.
```
java.lang.ClassCastException: java.lang.Integer cannot be cast to org.apache.spark.unsafe.types.UTF8String
	at org.apache.spark.sql.catalyst.expressions.BaseGenericInternalRow$class.getUTF8String(rows.scala:46)
	at org.apache.spark.sql.catalyst.expressions.GenericInternalRow.getUTF8String(rows.scala:221)
	at org.apache.spark.sql.catalyst.expressions.GeneratedClass$SpecificUnsafeProjection.apply(generated.java:42)
	at org.apache.spark.sql.execution.Generate$$anonfun$doExecute$1$$anonfun$apply$9.apply(Generate.scala:98)
	at org.apache.spark.sql.execution.Generate$$anonfun$doExecute$1$$anonfun$apply$9.apply(Generate.scala:96)
	at scala.collection.Iterator$$anon$11.next(Iterator.scala:370)
	at scala.collection.Iterator$$anon$11.next(Iterator.scala:370)
	at scala.collection.Iterator$class.foreach(Iterator.scala:742)
	at scala.collection.AbstractIterator.foreach(Iterator.scala:1194)
        <stack-trace omitted.....>
```
In this case the generated outputs are wrongly resolved from its child (LocalRelation) due to
https://github.com/apache/spark/blob/master/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/Analyzer.scala#L537-L548
## How was this patch tested?

(Please explain how this patch was tested. E.g. unit tests, integration tests, manual tests)

Added unit tests in hive/SQLQuerySuite and AnalysisSuite

Author: Dilip Biswal <dbiswal@us.ibm.com>

Closes #11497 from dilipbiswal/spark-13651.
2016-03-07 09:46:28 -08:00
Andrew Or bc7a3ec290 [SPARK-13685][SQL] Rename catalog.Catalog to ExternalCatalog
## What changes were proposed in this pull request?

Today we have `analysis.Catalog` and `catalog.Catalog`. In the future the former will call the latter. When that happens, if both of them are still called `Catalog` it will be very confusing. This patch renames the latter `ExternalCatalog` because it is expected to talk to external systems.

## How was this patch tested?

Jenkins.

Author: Andrew Or <andrew@databricks.com>

Closes #11526 from andrewor14/rename-catalog.
2016-03-07 00:14:40 -08:00
gatorsmile adce5ee721 [SPARK-12720][SQL] SQL Generation Support for Cube, Rollup, and Grouping Sets
#### What changes were proposed in this pull request?

This PR is for supporting SQL generation for cube, rollup and grouping sets.

For example, a query using rollup:
```SQL
SELECT count(*) as cnt, key % 5, grouping_id() FROM t1 GROUP BY key % 5 WITH ROLLUP
```
Original logical plan:
```
  Aggregate [(key#17L % cast(5 as bigint))#47L,grouping__id#46],
            [(count(1),mode=Complete,isDistinct=false) AS cnt#43L,
             (key#17L % cast(5 as bigint))#47L AS _c1#45L,
             grouping__id#46 AS _c2#44]
  +- Expand [List(key#17L, value#18, (key#17L % cast(5 as bigint))#47L, 0),
             List(key#17L, value#18, null, 1)],
            [key#17L,value#18,(key#17L % cast(5 as bigint))#47L,grouping__id#46]
     +- Project [key#17L,
                 value#18,
                 (key#17L % cast(5 as bigint)) AS (key#17L % cast(5 as bigint))#47L]
        +- Subquery t1
           +- Relation[key#17L,value#18] ParquetRelation
```
Converted SQL:
```SQL
  SELECT count( 1) AS `cnt`,
         (`t1`.`key` % CAST(5 AS BIGINT)),
         grouping_id() AS `_c2`
  FROM `default`.`t1`
  GROUP BY (`t1`.`key` % CAST(5 AS BIGINT))
  GROUPING SETS (((`t1`.`key` % CAST(5 AS BIGINT))), ())
```

#### How was the this patch tested?

Added eight test cases in `LogicalPlanToSQLSuite`.

Author: gatorsmile <gatorsmile@gmail.com>
Author: xiaoli <lixiao1983@gmail.com>
Author: Xiao Li <xiaoli@Xiaos-MacBook-Pro.local>

Closes #11283 from gatorsmile/groupingSetsToSQL.
2016-03-05 19:25:03 +08:00
Andrew Or b7d4147421 [SPARK-13633][SQL] Move things into catalyst.parser package
## What changes were proposed in this pull request?

This patch simply moves things to existing package `o.a.s.sql.catalyst.parser` in an effort to reduce the size of the diff in #11048. This is conceptually the same as a recently merged patch #11482.

## How was this patch tested?

Jenkins.

Author: Andrew Or <andrew@databricks.com>

Closes #11506 from andrewor14/parser-package.
2016-03-04 10:32:00 -08:00
Davies Liu dd83c209f1 [SPARK-13603][SQL] support SQL generation for subquery
## What changes were proposed in this pull request?

This is support SQL generation for subquery expressions, which will be replaced to a SubqueryHolder inside SQLBuilder recursively.

## How was this patch tested?

Added unit tests.

Author: Davies Liu <davies@databricks.com>

Closes #11453 from davies/sql_subquery.
2016-03-04 16:18:15 +08:00
Davies Liu b373a88862 [SPARK-13415][SQL] Visualize subquery in SQL web UI
## What changes were proposed in this pull request?

This PR support visualization for subquery in SQL web UI, also improve the explain of subquery, especially when it's used together with whole stage codegen.

For example:
```python
>>> sqlContext.range(100).registerTempTable("range")
>>> sqlContext.sql("select id / (select sum(id) from range) from range where id > (select id from range limit 1)").explain(True)
== Parsed Logical Plan ==
'Project [unresolvedalias(('id / subquery#9), None)]
:  +- 'SubqueryAlias subquery#9
:     +- 'Project [unresolvedalias('sum('id), None)]
:        +- 'UnresolvedRelation `range`, None
+- 'Filter ('id > subquery#8)
   :  +- 'SubqueryAlias subquery#8
   :     +- 'GlobalLimit 1
   :        +- 'LocalLimit 1
   :           +- 'Project [unresolvedalias('id, None)]
   :              +- 'UnresolvedRelation `range`, None
   +- 'UnresolvedRelation `range`, None

== Analyzed Logical Plan ==
(id / scalarsubquery()): double
Project [(cast(id#0L as double) / cast(subquery#9 as double)) AS (id / scalarsubquery())#11]
:  +- SubqueryAlias subquery#9
:     +- Aggregate [(sum(id#0L),mode=Complete,isDistinct=false) AS sum(id)#10L]
:        +- SubqueryAlias range
:           +- Range 0, 100, 1, 4, [id#0L]
+- Filter (id#0L > subquery#8)
   :  +- SubqueryAlias subquery#8
   :     +- GlobalLimit 1
   :        +- LocalLimit 1
   :           +- Project [id#0L]
   :              +- SubqueryAlias range
   :                 +- Range 0, 100, 1, 4, [id#0L]
   +- SubqueryAlias range
      +- Range 0, 100, 1, 4, [id#0L]

== Optimized Logical Plan ==
Project [(cast(id#0L as double) / cast(subquery#9 as double)) AS (id / scalarsubquery())#11]
:  +- SubqueryAlias subquery#9
:     +- Aggregate [(sum(id#0L),mode=Complete,isDistinct=false) AS sum(id)#10L]
:        +- Range 0, 100, 1, 4, [id#0L]
+- Filter (id#0L > subquery#8)
   :  +- SubqueryAlias subquery#8
   :     +- GlobalLimit 1
   :        +- LocalLimit 1
   :           +- Project [id#0L]
   :              +- Range 0, 100, 1, 4, [id#0L]
   +- Range 0, 100, 1, 4, [id#0L]

== Physical Plan ==
WholeStageCodegen
:  +- Project [(cast(id#0L as double) / cast(subquery#9 as double)) AS (id / scalarsubquery())#11]
:     :  +- Subquery subquery#9
:     :     +- WholeStageCodegen
:     :        :  +- TungstenAggregate(key=[], functions=[(sum(id#0L),mode=Final,isDistinct=false)], output=[sum(id)#10L])
:     :        :     +- INPUT
:     :        +- Exchange SinglePartition, None
:     :           +- WholeStageCodegen
:     :              :  +- TungstenAggregate(key=[], functions=[(sum(id#0L),mode=Partial,isDistinct=false)], output=[sum#14L])
:     :              :     +- Range 0, 1, 4, 100, [id#0L]
:     +- Filter (id#0L > subquery#8)
:        :  +- Subquery subquery#8
:        :     +- CollectLimit 1
:        :        +- WholeStageCodegen
:        :           :  +- Project [id#0L]
:        :           :     +- Range 0, 1, 4, 100, [id#0L]
:        +- Range 0, 1, 4, 100, [id#0L]
```

The web UI looks like:

![subquery](https://cloud.githubusercontent.com/assets/40902/13377963/932bcbae-dda7-11e5-82f7-03c9be85d77c.png)

This PR also change the tree structure of WholeStageCodegen to make it consistent than others. Before this change, Both WholeStageCodegen and InputAdapter hold a references to the same plans, those could be updated without notify another, causing problems, this is discovered by #11403 .

## How was this patch tested?

Existing tests, also manual tests with the example query, check the explain and web UI.

Author: Davies Liu <davies@databricks.com>

Closes #11417 from davies/viz_subquery.
2016-03-03 17:36:48 -08:00
Dongjoon Hyun b5f02d6743 [SPARK-13583][CORE][STREAMING] Remove unused imports and add checkstyle rule
## What changes were proposed in this pull request?

After SPARK-6990, `dev/lint-java` keeps Java code healthy and helps PR review by saving much time.
This issue aims remove unused imports from Java/Scala code and add `UnusedImports` checkstyle rule to help developers.

## How was this patch tested?
```
./dev/lint-java
./build/sbt compile
```

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #11438 from dongjoon-hyun/SPARK-13583.
2016-03-03 10:12:32 +00:00
Sean Owen e97fc7f176 [SPARK-13423][WIP][CORE][SQL][STREAMING] Static analysis fixes for 2.x
## What changes were proposed in this pull request?

Make some cross-cutting code improvements according to static analysis. These are individually up for discussion since they exist in separate commits that can be reverted. The changes are broadly:

- Inner class should be static
- Mismatched hashCode/equals
- Overflow in compareTo
- Unchecked warnings
- Misuse of assert, vs junit.assert
- get(a) + getOrElse(b) -> getOrElse(a,b)
- Array/String .size -> .length (occasionally, -> .isEmpty / .nonEmpty) to avoid implicit conversions
- Dead code
- tailrec
- exists(_ == ) -> contains find + nonEmpty -> exists filter + size -> count
- reduce(_+_) -> sum map + flatten -> map

The most controversial may be .size -> .length simply because of its size. It is intended to avoid implicits that might be expensive in some places.

## How was the this patch tested?

Existing Jenkins unit tests.

Author: Sean Owen <sowen@cloudera.com>

Closes #11292 from srowen/SPARK-13423.
2016-03-03 09:54:09 +00:00
Dongjoon Hyun 02b7677e95 [HOT-FIX] Recover some deprecations for 2.10 compatibility.
## What changes were proposed in this pull request?

#11479 [SPARK-13627] broke 2.10 compatibility: [2.10-Build](https://amplab.cs.berkeley.edu/jenkins/view/Spark%20QA%20Compile/job/spark-master-compile-maven-scala-2.10/292/console)
At this moment, we need to support both 2.10 and 2.11.
This PR recovers some deprecated methods which were replace by [SPARK-13627].

## How was this patch tested?

Jenkins build: Both 2.10, 2.11.

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #11488 from dongjoon-hyun/hotfix_compatibility_with_2.10.
2016-03-03 09:53:02 +00:00
Liang-Chi Hsieh 7b25dc7b7e [SPARK-13466] [SQL] Remove projects that become redundant after column pruning rule
JIRA: https://issues.apache.org/jira/browse/SPARK-13466

## What changes were proposed in this pull request?

With column pruning rule in optimizer, some Project operators will become redundant. We should remove these redundant Projects.

For an example query:

    val input = LocalRelation('key.int, 'value.string)

    val query =
      Project(Seq($"x.key", $"y.key"),
        Join(
          SubqueryAlias("x", input),
          BroadcastHint(SubqueryAlias("y", input)), Inner, None))

After the first run of column pruning, it would like:

    Project(Seq($"x.key", $"y.key"),
      Join(
        Project(Seq($"x.key"), SubqueryAlias("x", input)),
        Project(Seq($"y.key"),      <-- inserted by the rule
        BroadcastHint(SubqueryAlias("y", input))),
        Inner, None))

Actually we don't need the outside Project now. This patch will remove it:

    Join(
      Project(Seq($"x.key"), SubqueryAlias("x", input)),
      Project(Seq($"y.key"),
      BroadcastHint(SubqueryAlias("y", input))),
      Inner, None)

## How was the this patch tested?

Unit test is added into ColumnPruningSuite.

Author: Liang-Chi Hsieh <viirya@gmail.com>

Closes #11341 from viirya/remove-redundant-project.
2016-03-03 00:06:46 -08:00
Liang-Chi Hsieh 1085bd862a [SPARK-13635] [SQL] Enable LimitPushdown optimizer rule because we have whole-stage codegen for Limit
JIRA: https://issues.apache.org/jira/browse/SPARK-13635

## What changes were proposed in this pull request?

LimitPushdown optimizer rule has been disabled due to no whole-stage codegen for Limit. As we have whole-stage codegen for Limit now, we should enable it.

## How was this patch tested?

As we only re-enable LimitPushdown optimizer rule, no need to add new tests for it.

Author: Liang-Chi Hsieh <viirya@gmail.com>

Closes #11483 from viirya/enable-limitpushdown.
2016-03-02 23:46:23 -08:00
Dongjoon Hyun 9c274ac4a6 [SPARK-13627][SQL][YARN] Fix simple deprecation warnings.
## What changes were proposed in this pull request?

This PR aims to fix the following deprecation warnings.
  * MethodSymbolApi.paramss--> paramLists
  * AnnotationApi.tpe -> tree.tpe
  * BufferLike.readOnly -> toList.
  * StandardNames.nme -> termNames
  * scala.tools.nsc.interpreter.AbstractFileClassLoader -> scala.reflect.internal.util.AbstractFileClassLoader
  * TypeApi.declarations-> decls

## How was this patch tested?

Check the compile build log and pass the tests.
```
./build/sbt
```

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #11479 from dongjoon-hyun/SPARK-13627.
2016-03-02 20:34:22 -08:00
Wenchen Fan b60b813799 [SPARK-13617][SQL] remove unnecessary GroupingAnalytics trait
## What changes were proposed in this pull request?

The `trait GroupingAnalytics` only has one implementation, it's an unnecessary abstraction. This PR removes it, and does some code simplification when resolving `GroupingSet`.

## How was this patch tested?

existing tests

Author: Wenchen Fan <wenchen@databricks.com>

Closes #11469 from cloud-fan/groupingset.
2016-03-02 20:18:57 -08:00
gatorsmile 8f8d8a2315 [SPARK-13609] [SQL] Support Column Pruning for MapPartitions
#### What changes were proposed in this pull request?

This PR is to prune unnecessary columns when the operator is  `MapPartitions`. The solution is to add an extra `Project` in the child node.

For the other two operators `AppendColumns` and `MapGroups`, it sounds doable. More discussions are required. The major reason is the current implementation of the `inputPlan` of `groupBy` is based on the child of `AppendColumns`. It might be a bug? Thus, will submit a separate PR.

#### How was this patch tested?

Added a test case in ColumnPruningSuite to verify the rule. Added another test case in DatasetSuite.scala to verify the data.

Author: gatorsmile <gatorsmile@gmail.com>

Closes #11460 from gatorsmile/datasetPruningNew.
2016-03-02 09:59:22 -08:00
lgieron d8afd45f89 [SPARK-13515] Make FormatNumber work irrespective of locale.
## What changes were proposed in this pull request?

Change in class FormatNumber to make it work irrespective of locale.

## How was this patch tested?

Unit tests.

Author: lgieron <lgieron@gmail.com>

Closes #11396 from lgieron/SPARK-13515_Fix_Format_Number.
2016-03-02 15:57:27 +00:00
Davies Liu c27ba0d547 [SPARK-13582] [SQL] defer dictionary decoding in parquet reader
## What changes were proposed in this pull request?

This PR defer the resolution from a id of dictionary to value until the column is actually accessed (inside getInt/getLong), this is very useful for those columns and rows that are filtered out. It's also useful for binary type, we will not need to copy all the byte arrays.

This PR also change the underlying type for small decimal that could be fit within a Int, in order to use getInt() to lookup the value from IntDictionary.

## How was this patch tested?

Manually test TPCDS Q7 with scale factor 10, saw about 30% improvements (after PR #11274).

Author: Davies Liu <davies@databricks.com>

Closes #11437 from davies/decode_dict.
2016-03-01 13:07:04 -08:00
Sameer Agarwal 4bd697da03 [SPARK-13123][SQL] Implement whole state codegen for sort
## What changes were proposed in this pull request?
This PR adds support for implementing whole state codegen for sort. Builds heaving on nongli 's PR: https://github.com/apache/spark/pull/11008 (which actually implements the feature), and adds the following changes on top:

- [x]  Generated code updates peak execution memory metrics
- [x]  Unit tests in `WholeStageCodegenSuite` and `SQLMetricsSuite`

## How was this patch tested?

New unit tests in `WholeStageCodegenSuite` and `SQLMetricsSuite`. Further, all existing sort tests should pass.

Author: Sameer Agarwal <sameer@databricks.com>
Author: Nong Li <nong@databricks.com>

Closes #11359 from sameeragarwal/sort-codegen.
2016-02-29 12:59:46 -08:00
gatorsmile bc65f60ef7 [SPARK-13544][SQL] Rewrite/Propagate Constraints for Aliases in Aggregate
#### What changes were proposed in this pull request?

After analysis by Analyzer, two operators could have alias. They are `Project` and `Aggregate`. So far, we only rewrite and propagate constraints if `Alias` is defined in `Project`. This PR is to resolve this issue in `Aggregate`.

#### How was this patch tested?

Added a test case for `Aggregate` in `ConstraintPropagationSuite`.

marmbrus sameeragarwal

Author: gatorsmile <gatorsmile@gmail.com>

Closes #11422 from gatorsmile/validConstraintsInUnaryNodes.
2016-02-29 10:10:04 -08:00
Cheng Lian 916fc34f98 [SPARK-13540][SQL] Supports using nested classes within Scala objects as Dataset element type
## What changes were proposed in this pull request?

Nested classes defined within Scala objects are translated into Java static nested classes. Unlike inner classes, they don't need outer scopes. But the analyzer still thinks that an outer scope is required.

This PR fixes this issue simply by checking whether a nested class is static before looking up its outer scope.

## How was this patch tested?

A test case is added to `DatasetSuite`. It checks contents of a Dataset whose element type is a nested class declared in a Scala object.

Author: Cheng Lian <lian@databricks.com>

Closes #11421 from liancheng/spark-13540-object-as-outer-scope.
2016-03-01 01:07:45 +08:00
Davies Liu 6df1e55a65 [SPARK-12313] [SQL] improve performance of BroadcastNestedLoopJoin
## What changes were proposed in this pull request?

Currently, BroadcastNestedLoopJoin is implemented for worst case, it's too slow, very easy to hang forever. This PR will create fast path for some joinType and buildSide, also improve the worst case (will use much less memory than before).

Before this PR, one task requires O(N*K) + O(K) in worst cases, N is number of rows from one partition of streamed table, it could hang the job (because of GC).

In order to workaround this for InnerJoin, we have to disable auto-broadcast, switch to CartesianProduct: This could be workaround for InnerJoin, see https://forums.databricks.com/questions/6747/how-do-i-get-a-cartesian-product-of-a-huge-dataset.html

In this PR, we will have fast path for these joins :

 InnerJoin with BuildLeft or BuildRight
 LeftOuterJoin with BuildRight
 RightOuterJoin with BuildLeft
 LeftSemi with BuildRight

These fast paths are all stream based (take one pass on streamed table), required O(1) memory.

All other join types and build types will take two pass on streamed table, one pass to find the matched rows that includes streamed part, which require O(1) memory, another pass to find the rows from build table that does not have a matched row from streamed table, which required O(K) memory, K is the number rows from build side, one bit per row, should be much smaller than the memory for broadcast. The following join types work in this way:

LeftOuterJoin with BuildLeft
RightOuterJoin with BuildRight
FullOuterJoin with BuildLeft or BuildRight
LeftSemi with BuildLeft

This PR also added tests for all the join types for BroadcastNestedLoopJoin.

After this PR, for InnerJoin with one small table, BroadcastNestedLoopJoin should be faster than CartesianProduct, we don't need that workaround anymore.

## How was the this patch tested?

Added unit tests.

Author: Davies Liu <davies@databricks.com>

Closes #11328 from davies/nested_loop.
2016-02-26 09:58:05 -08:00
Cheng Lian 3fa6491be6 [SPARK-13473][SQL] Don't push predicate through project with nondeterministic field(s)
## What changes were proposed in this pull request?

Predicates shouldn't be pushed through project with nondeterministic field(s).

See https://github.com/graphframes/graphframes/pull/23 and SPARK-13473 for more details.

This PR targets master, branch-1.6, and branch-1.5.

## How was this patch tested?

A test case is added in `FilterPushdownSuite`. It constructs a query plan where a filter is over a project with a nondeterministic field. Optimized query plan shouldn't change in this case.

Author: Cheng Lian <lian@databricks.com>

Closes #11348 from liancheng/spark-13473-no-ppd-through-nondeterministic-project-field.
2016-02-25 20:43:03 +08:00
Davies Liu 07f92ef1fa [SPARK-13376] [SPARK-13476] [SQL] improve column pruning
## What changes were proposed in this pull request?

This PR mostly rewrite the ColumnPruning rule to support most of the SQL logical plans (except those for Dataset).

This PR also fix a bug in Generate, it should always output UnsafeRow, added an regression test for that.

## How was this patch tested?

This is test by unit tests, also manually test with TPCDS Q78, which could prune all unused columns successfully, improved the performance by 78% (from 22s to 12s).

Author: Davies Liu <davies@databricks.com>

Closes #11354 from davies/fix_column_pruning.
2016-02-25 00:13:07 -08:00
Michael Armbrust 2b042577fb [SPARK-13092][SQL] Add ExpressionSet for constraint tracking
This PR adds a new abstraction called an `ExpressionSet` which attempts to canonicalize expressions to remove cosmetic differences.  Deterministic expressions that are in the set after canonicalization will always return the same answer given the same input (i.e. false positives should not be possible). However, it is possible that two canonical expressions that are not equal will in fact return the same answer given any input (i.e. false negatives are possible).

```scala
val set = AttributeSet('a + 1 :: 1 + 'a :: Nil)

set.iterator => Iterator('a + 1)
set.contains('a + 1) => true
set.contains(1 + 'a) => true
set.contains('a + 2) => false
```

Other relevant changes include:
 - Since this concept overlaps with the existing `semanticEquals` and `semanticHash`, those functions are also ported to this new infrastructure.
 - A memoized `canonicalized` version of the expression is added as a `lazy val` to `Expression` and is used by both `semanticEquals` and `ExpressionSet`.
 - A set of unit tests for `ExpressionSet` are added
 - Tests which expect `semanticEquals` to be less intelligent than it now is are updated.

As a followup, we should consider auditing the places where we do `O(n)` `semanticEquals` operations and replace them with `ExpressionSet`.  We should also consider consolidating `AttributeSet` as a specialized factory for an `ExpressionSet.`

Author: Michael Armbrust <michael@databricks.com>

Closes #11338 from marmbrus/expressionSet.
2016-02-24 19:43:00 -08:00
Yin Huai cbb0b65ad5 [SPARK-13383][SQL] Fix test
## What changes were proposed in this pull request?

Reverting SPARK-13376 (d563c8fa01) affects the test added by SPARK-13383. So, I am fixing the test.

Author: Yin Huai <yhuai@databricks.com>

Closes #11355 from yhuai/SPARK-13383-fix-test.
2016-02-24 16:13:55 -08:00
Reynold Xin f92f53faee Revert "[SPARK-13321][SQL] Support nested UNION in parser"
This reverts commit 55d6fdf22d.
2016-02-24 12:25:02 -08:00
Reynold Xin 65805ab6ea Revert "Revert "[SPARK-13383][SQL] Keep broadcast hint after column pruning""
This reverts commit 382b27babf.
2016-02-24 12:03:45 -08:00
Reynold Xin d563c8fa01 Revert "[SPARK-13376] [SQL] improve column pruning"
This reverts commit e9533b419e.
2016-02-24 11:58:32 -08:00
Reynold Xin 382b27babf Revert "[SPARK-13383][SQL] Keep broadcast hint after column pruning"
This reverts commit f373986997.
2016-02-24 11:58:12 -08:00