Quite a few Spark SQL join operators broadcast one side of the join to all nodes. The are a few problems with this:
- This conflates broadcasting (a data exchange) with joining. Data exchanges should be managed by a different operator.
- All these nodes implement their own (duplicate) broadcasting logic.
- Re-use of indices is quite hard.
This PR defines both a ```BroadcastDistribution``` and ```BroadcastPartitioning```, these contain a `BroadcastMode`. The `BroadcastMode` defines the way in which we transform the Array of `InternalRow`'s into an index. We currently support the following `BroadcastMode`'s:
- IdentityBroadcastMode: This broadcasts the rows in their original form.
- HashSetBroadcastMode: This applies a projection to the input rows, deduplicates these rows and broadcasts the resulting `Set`.
- HashedRelationBroadcastMode: This transforms the input rows into a `HashedRelation`, and broadcasts this index.
To match this distribution we implement a ```BroadcastExchange``` operator which will perform the broadcast for us, and have ```EnsureRequirements``` plan this operator. The old Exchange operator has been renamed into ShuffleExchange in order to clearly separate between Shuffled and Broadcasted exchanges. Finally the classes in Exchange.scala have been moved to a dedicated package.
cc rxin davies
Author: Herman van Hovell <hvanhovell@questtec.nl>
Closes#11083 from hvanhovell/SPARK-13136.
## What changes were proposed in this pull request?
This patch renames logical.Subquery to logical.SubqueryAlias, which is a more appropriate name for this operator (versus subqueries as expressions).
## How was the this patch tested?
Unit tests.
Author: Reynold Xin <rxin@databricks.com>
Closes#11288 from rxin/SPARK-13420.
This PR introduces several major changes:
1. Replacing `Expression.prettyString` with `Expression.sql`
The `prettyString` method is mostly an internal, developer faced facility for debugging purposes, and shouldn't be exposed to users.
1. Using SQL-like representation as column names for selected fields that are not named expression (back-ticks and double quotes should be removed)
Before, we were using `prettyString` as column names when possible, and sometimes the result column names can be weird. Here are several examples:
Expression | `prettyString` | `sql` | Note
------------------ | -------------- | ---------- | ---------------
`a && b` | `a && b` | `a AND b` |
`a.getField("f")` | `a[f]` | `a.f` | `a` is a struct
1. Adding trait `NonSQLExpression` extending from `Expression` for expressions that don't have a SQL representation (e.g. Scala UDF/UDAF and Java/Scala object expressions used for encoders)
`NonSQLExpression.sql` may return an arbitrary user facing string representation of the expression.
Author: Cheng Lian <lian@databricks.com>
Closes#10757 from liancheng/spark-12799.simplify-expression-string-methods.
```scala
// case 1: missing sort columns are resolvable if join is true
sql("SELECT explode(a) AS val, b FROM data WHERE b < 2 order by val, c")
// case 2: missing sort columns are not resolvable if join is false. Thus, issue an error message in this case
sql("SELECT explode(a) AS val FROM data order by val, c")
```
When sort columns are not in `Generate`, we can resolve them when `join` is equal to `true`. Still trying to add more test cases for the other `UnaryNode` types.
Could you review the changes? davies cloud-fan Thanks!
Author: gatorsmile <gatorsmile@gmail.com>
Closes#11198 from gatorsmile/missingInSort.
Using GroupingSets will generate a wrong result when Aggregate Functions containing GroupBy columns.
This PR is to fix it. Since the code changes are very small. Maybe we also can merge it to 1.6
For example, the following query returns a wrong result:
```scala
sql("select course, sum(earnings) as sum from courseSales group by course, earnings" +
" grouping sets((), (course), (course, earnings))" +
" order by course, sum").show()
```
Before the fix, the results are like
```
[null,null]
[Java,null]
[Java,20000.0]
[Java,30000.0]
[dotNET,null]
[dotNET,5000.0]
[dotNET,10000.0]
[dotNET,48000.0]
```
After the fix, the results become correct:
```
[null,113000.0]
[Java,20000.0]
[Java,30000.0]
[Java,50000.0]
[dotNET,5000.0]
[dotNET,10000.0]
[dotNET,48000.0]
[dotNET,63000.0]
```
UPDATE: This PR also deprecated the external column: GROUPING__ID.
Author: gatorsmile <gatorsmile@gmail.com>
Closes#11100 from gatorsmile/groupingSets.
This patch adds a new optimizer rule for performing limit pushdown. Limits will now be pushed down in two cases:
- If a limit is on top of a `UNION ALL` operator, then a partition-local limit operator will be pushed to each of the union operator's children.
- If a limit is on top of an `OUTER JOIN` then a partition-local limit will be pushed to one side of the join. For `LEFT OUTER` and `RIGHT OUTER` joins, the limit will be pushed to the left and right side, respectively. For `FULL OUTER` join, we will only push limits when at most one of the inputs is already limited: if one input is limited we will push a smaller limit on top of it and if neither input is limited then we will limit the input which is estimated to be larger.
These optimizations were proposed previously by gatorsmile in #10451 and #10454, but those earlier PRs were closed and deferred for later because at that time Spark's physical `Limit` operator would trigger a full shuffle to perform global limits so there was a chance that pushdowns could actually harm performance by causing additional shuffles/stages. In #7334, we split the `Limit` operator into separate `LocalLimit` and `GlobalLimit` operators, so we can now push down only local limits (which don't require extra shuffles). This patch is based on both of gatorsmile's patches, with changes and simplifications due to partition-local-limiting.
When we push down the limit, we still keep the original limit in place, so we need a mechanism to ensure that the optimizer rule doesn't keep pattern-matching once the limit has been pushed down. In order to handle this, this patch adds a `maxRows` method to `SparkPlan` which returns the maximum number of rows that the plan can compute, then defines the pushdown rules to only push limits to children if the children's maxRows are greater than the limit's maxRows. This idea is carried over from #10451; see that patch for additional discussion.
Author: Josh Rosen <joshrosen@databricks.com>
Closes#11121 from JoshRosen/limit-pushdown-2.
This pull request has the following changes:
1. Moved UserDefinedFunction into expressions package. This is more consistent with how we structure the packages for window functions and UDAFs.
2. Moved UserDefinedPythonFunction into execution.python package, so we don't have a random private class in the top level sql package.
3. Move everything in execution/python.scala into the newly created execution.python package.
Most of the diffs are just straight copy-paste.
Author: Reynold Xin <rxin@databricks.com>
Closes#11181 from rxin/SPARK-13296.
Previously we were using Option[String] and None to indicate the case when Spark fails to generate SQL. It is easier to just use exceptions to propagate error cases, rather than having for comprehension everywhere. I also introduced a "build" function that simplifies string concatenation (i.e. no need to reason about whether we have an extra space or not).
Author: Reynold Xin <rxin@databricks.com>
Closes#11171 from rxin/SPARK-13282.
The current implementation of ResolveSortReferences can only push one missing attributes into it's child, it failed to analyze TPCDS Q98, because of there are two missing attributes in that (one from Window, another from Aggregate).
Author: Davies Liu <davies@databricks.com>
Closes#11153 from davies/resolve_sort.
For lots of SQL operators, we have metrics for both of input and output, the number of input rows should be exactly the number of output rows of child, we could only have metrics for output rows.
After we improved the performance using whole stage codegen, the overhead of SQL metrics are not trivial anymore, we should avoid that if it's not necessary.
This PR remove all the SQL metrics for number of input rows, add SQL metric of number of output rows for all LeafNode. All remove the SQL metrics from those operators that have the same number of rows from input and output (for example, Projection, we may don't need that).
The new SQL UI will looks like:
Author: Davies Liu <davies@databricks.com>
Closes#11163 from davies/remove_metrics.
Grouping() returns a column is aggregated or not, grouping_id() returns the aggregation levels.
grouping()/grouping_id() could be used with window function, but does not work in having/sort clause, will be fixed by another PR.
The GROUPING__ID/grouping_id() in Hive is wrong (according to docs), we also did it wrongly, this PR change that to match the behavior in most databases (also the docs of Hive).
Author: Davies Liu <davies@databricks.com>
Closes#10677 from davies/grouping.
This PR addresses two issues:
- Self join does not work in SQL Generation
- When creating new instances for `LogicalRelation`, `metastoreTableIdentifier` is lost.
liancheng Could you please review the code changes? Thank you!
Author: gatorsmile <gatorsmile@gmail.com>
Closes#11084 from gatorsmile/selfJoinInSQLGen.
Some analysis rules generate aliases or auxiliary attribute references with the same name but different expression IDs. For example, `ResolveAggregateFunctions` introduces `havingCondition` and `aggOrder`, and `DistinctAggregationRewriter` introduces `gid`.
This is OK for normal query execution since these attribute references get expression IDs. However, it's troublesome when converting resolved query plans back to SQL query strings since expression IDs are erased.
Here's an example Spark 1.6.0 snippet for illustration:
```scala
sqlContext.range(10).select('id as 'a, 'id as 'b).registerTempTable("t")
sqlContext.sql("SELECT SUM(a) FROM t GROUP BY a, b ORDER BY COUNT(a), COUNT(b)").explain(true)
```
The above code produces the following resolved plan:
```
== Analyzed Logical Plan ==
_c0: bigint
Project [_c0#101L]
+- Sort [aggOrder#102L ASC,aggOrder#103L ASC], true
+- Aggregate [a#47L,b#48L], [(sum(a#47L),mode=Complete,isDistinct=false) AS _c0#101L,(count(a#47L),mode=Complete,isDistinct=false) AS aggOrder#102L,(count(b#48L),mode=Complete,isDistinct=false) AS aggOrder#103L]
+- Subquery t
+- Project [id#46L AS a#47L,id#46L AS b#48L]
+- LogicalRDD [id#46L], MapPartitionsRDD[44] at range at <console>:26
```
Here we can see that both aggregate expressions in `ORDER BY` are extracted into an `Aggregate` operator, and both of them are named `aggOrder` with different expression IDs.
The solution is to automatically add the expression IDs into the attribute name for the Alias and AttributeReferences that are generated by Analyzer in SQL Generation.
In this PR, it also resolves another issue. Users could use the same name as the internally generated names. The duplicate names should not cause name ambiguity. When resolving the column, Catalyst should not pick the column that is internally generated.
Could you review the solution? marmbrus liancheng
I did not set the newly added flag for all the alias and attribute reference generated by Analyzers. Please let me know if I should do it? Thank you!
Author: gatorsmile <gatorsmile@gmail.com>
Closes#11050 from gatorsmile/namingConflicts.
The patch for SPARK-8964 ("use Exchange to perform shuffle in Limit" / #7334) inadvertently broke the planning of the TakeOrderedAndProject operator: because ReturnAnswer was the new root of the query plan, the TakeOrderedAndProject rule was unable to match before BasicOperators.
This patch fixes this by moving the `TakeOrderedAndCollect` and `CollectLimit` rules into the same strategy.
In addition, I made changes to the TakeOrderedAndProject operator in order to make its `doExecute()` method lazy and added a new TakeOrderedAndProjectSuite which tests the new code path.
/cc davies and marmbrus for review.
Author: Josh Rosen <joshrosen@databricks.com>
Closes#11145 from JoshRosen/take-ordered-and-project-fix.
WIP: running tests. Code needs a bit of clean up.
This patch completes the vectorized decoding with the goal of passing the existing
tests. There is still more patches to support the rest of the format spec, even
just for flat schemas.
This patch adds a new flag to enable the vectorized decoding. Tests were updated
to try with both modes where applicable.
Once this is working well, we can remove the previous code path.
Author: Nong Li <nong@databricks.com>
Closes#11055 from nongli/spark-12992-2.
JIRA: https://issues.apache.org/jira/browse/SPARK-12850
This PR is to support bucket pruning when the predicates are `EqualTo`, `EqualNullSafe`, `IsNull`, `In`, and `InSet`.
Like HIVE, in this PR, the bucket pruning works when the bucketing key has one and only one column.
So far, I do not find a way to verify how many buckets are actually scanned. However, I did verify it when doing the debug. Could you provide a suggestion how to do it properly? Thank you! cloud-fan yhuai rxin marmbrus
BTW, we can add more cases to support complex predicate including `Or` and `And`. Please let me know if I should do it in this PR.
Maybe we also need to add test cases to verify if bucket pruning works well for each data type.
Author: gatorsmile <gatorsmile@gmail.com>
Closes#10942 from gatorsmile/pruningBuckets.
Spark SQL should collapse adjacent `Repartition` operators and only keep the last one.
Author: Josh Rosen <joshrosen@databricks.com>
Closes#11064 from JoshRosen/collapse-repartition.
As benchmarked and discussed here: https://github.com/apache/spark/pull/10786/files#r50038294, benefits from codegen, the declarative aggregate function could be much faster than imperative one.
Author: Davies Liu <davies@databricks.com>
Closes#10960 from davies/stddev.
It is not valid to call `toAttribute` on a `NamedExpression` unless we know for sure that the child produced that `NamedExpression`. The current code worked fine when the grouping expressions were simple, but when they were a derived value this blew up at execution time.
Author: Michael Armbrust <michael@databricks.com>
Closes#11013 from marmbrus/groupByFunction-master.
JIRA: https://issues.apache.org/jira/browse/SPARK-12705
**Scope:**
This PR is a general fix for sorting reference resolution when the child's `outputSet` does not have the order-by attributes (called, *missing attributes*):
- UnaryNode support is limited to `Project`, `Window`, `Aggregate`, `Distinct`, `Filter`, `RepartitionByExpression`.
- We will not try to resolve the missing references inside a subquery, unless the outputSet of this subquery contains it.
**General Reference Resolution Rules:**
- Jump over the nodes with the following types: `Distinct`, `Filter`, `RepartitionByExpression`. Do not need to add missing attributes. The reason is their `outputSet` is decided by their `inputSet`, which is the `outputSet` of their children.
- Group-by expressions in `Aggregate`: missing order-by attributes are not allowed to be added into group-by expressions since it will change the query result. Thus, in RDBMS, it is not allowed.
- Aggregate expressions in `Aggregate`: if the group-by expressions in `Aggregate` contains the missing attributes but aggregate expressions do not have it, just add them into the aggregate expressions. This can resolve the analysisExceptions thrown by the three TCPDS queries.
- `Project` and `Window` are special. We just need to add the missing attributes to their `projectList`.
**Implementation:**
1. Traverse the whole tree in a pre-order manner to find all the resolvable missing order-by attributes.
2. Traverse the whole tree in a post-order manner to add the found missing order-by attributes to the node if their `inputSet` contains the attributes.
3. If the origins of the missing order-by attributes are different nodes, each pass only resolves the missing attributes that are from the same node.
**Risk:**
Low. This rule will be trigger iff ```!s.resolved && child.resolved``` is true. Thus, very few cases are affected.
Author: gatorsmile <gatorsmile@gmail.com>
Closes#10678 from gatorsmile/sortWindows.
This patch changes Spark's build to make Scala 2.11 the default Scala version. To be clear, this does not mean that Spark will stop supporting Scala 2.10: users will still be able to compile Spark for Scala 2.10 by following the instructions on the "Building Spark" page; however, it does mean that Scala 2.11 will be the default Scala version used by our CI builds (including pull request builds).
The Scala 2.11 compiler is faster than 2.10, so I think we'll be able to look forward to a slight speedup in our CI builds (it looks like it's about 2X faster for the Maven compile-only builds, for instance).
After this patch is merged, I'll update Jenkins to add new compile-only jobs to ensure that Scala 2.10 compilation doesn't break.
Author: Josh Rosen <joshrosen@databricks.com>
Closes#10608 from JoshRosen/SPARK-6363.
And ClientWrapper -> HiveClientImpl.
I have some followup pull requests to introduce a new internal catalog, and I think this new naming reflects better the functionality of the two classes.
Author: Reynold Xin <rxin@databricks.com>
Closes#10981 from rxin/SPARK-13076.
JIRA: https://issues.apache.org/jira/browse/SPARK-12968
Implement command to set current database.
Author: Liang-Chi Hsieh <viirya@gmail.com>
Author: Liang-Chi Hsieh <viirya@appier.com>
Closes#10916 from viirya/ddl-use-database.
This PR moves all the functionality provided by the SparkSQLParser/ExtendedHiveQlParser to the new Parser hierarchy (SparkQl/HiveQl). This also improves the current SET command parsing: the current implementation swallows ```set role ...``` and ```set autocommit ...``` commands, this PR respects these commands (and passes them on to Hive).
This PR and https://github.com/apache/spark/pull/10723 end the use of Parser-Combinator parsers for SQL parsing. As a result we can also remove the ```AbstractSQLParser``` in Catalyst.
The PR is marked WIP as long as it doesn't pass all tests.
cc rxin viirya winningsix (this touches https://github.com/apache/spark/pull/10144)
Author: Herman van Hovell <hvanhovell@questtec.nl>
Closes#10905 from hvanhovell/SPARK-12866.
This PR is a follow-up of PR #10541. It integrates the newly introduced SQL generation feature with native view to make native view canonical.
In this PR, a new SQL option `spark.sql.nativeView.canonical` is added. When this option and `spark.sql.nativeView` are both `true`, Spark SQL tries to handle `CREATE VIEW` DDL statements using SQL query strings generated from view definition logical plans. If we failed to map the plan to SQL, we fallback to the original native view approach.
One important issue this PR fixes is that, now we can use CTE when defining a view. Originally, when native view is turned on, we wrap the view definition text with an extra `SELECT`. However, HiveQL parser doesn't allow CTE appearing as a subquery. Namely, something like this is disallowed:
```sql
SELECT n
FROM (
WITH w AS (SELECT 1 AS n)
SELECT * FROM w
) v
```
This PR fixes this issue because the extra `SELECT` is no longer needed (also, CTE expressions are inlined as subqueries during analysis phase, thus there won't be CTE expressions in the generated SQL query string).
Author: Cheng Lian <lian@databricks.com>
Author: Yin Huai <yhuai@databricks.com>
Closes#10733 from liancheng/spark-12728.integrate-sql-gen-with-native-view.
This patch adds support for complex types for ColumnarBatch. ColumnarBatch supports structs
and arrays. There is a simple mapping between the richer catalyst types to these two. Strings
are treated as an array of bytes.
ColumnarBatch will contain a column for each node of the schema. Non-complex schemas consists
of just leaf nodes. Structs represent an internal node with one child for each field. Arrays
are internal nodes with one child. Structs just contain nullability. Arrays contain offsets
and lengths into the child array. This structure is able to handle arbitrary nesting. It has
the key property that we maintain columnar throughout and that primitive types are only stored
in the leaf nodes and contiguous across rows. For example, if the schema is
```
array<array<int>>
```
There are three columns in the schema. The internal nodes each have one children. The leaf node contains all the int data stored consecutively.
As part of this, this patch adds append APIs in addition to the Put APIs (e.g. putLong(rowid, v)
vs appendLong(v)). These APIs are necessary when the batch contains variable length elements.
The vectors are not fixed length and will grow as necessary. This should make the usage a lot
simpler for the writer.
Author: Nong Li <nong@databricks.com>
Closes#10820 from nongli/spark-12854.
This PR adds a new table option (`skip_hive_metadata`) that'd allow the user to skip storing the table metadata in hive metadata format. While this could be useful in general, the specific use-case for this change is that Hive doesn't handle wide schemas well (see https://issues.apache.org/jira/browse/SPARK-12682 and https://issues.apache.org/jira/browse/SPARK-6024) which in turn prevents such tables from being queried in SparkSQL.
Author: Sameer Agarwal <sameer@databricks.com>
Closes#10826 from sameeragarwal/skip-hive-metadata.
When users are using `partitionBy` and `bucketBy` at the same time, some bucketing columns might be part of partitioning columns. For example,
```
df.write
.format(source)
.partitionBy("i")
.bucketBy(8, "i", "k")
.saveAsTable("bucketed_table")
```
However, in the above case, adding column `i` into `bucketBy` is useless. It is just wasting extra CPU when reading or writing bucket tables. Thus, like Hive, we can issue an exception and let users do the change.
Also added a test case for checking if the information of `sortBy` and `bucketBy` columns are correctly saved in the metastore table.
Could you check if my understanding is correct? cloud-fan rxin marmbrus Thanks!
Author: gatorsmile <gatorsmile@gmail.com>
Closes#10891 from gatorsmile/commonKeysInPartitionByBucketBy.
ErrorPositionSuite and one of the HiveComparisonTest tests have been consistently failing on the Hadoop 2.3 SBT build (but on no other builds). I believe that this is due to test isolation issues (e.g. tests sharing state via the sets of temporary tables that are registered to TestHive).
This patch attempts to improve the isolation of these tests in order to address this issue.
Author: Josh Rosen <joshrosen@databricks.com>
Closes#10884 from JoshRosen/fix-failing-hadoop-2.3-hive-tests.
When users turn off bucketing in SQLConf, we should issue some messages to tell users these operations will be converted to normal way.
Also added a test case for this scenario and fixed the helper function.
Do you think this PR is helpful when using bucket tables? cloud-fan Thank you!
Author: gatorsmile <gatorsmile@gmail.com>
Closes#10870 from gatorsmile/bucketTableWritingTestcases.
The current parser turns a decimal literal, for example ```12.1```, into a Double. The problem with this approach is that we convert an exact literal into a non-exact ```Double```. The PR changes this behavior, a Decimal literal is now converted into an extact ```BigDecimal```.
The behavior for scientific decimals, for example ```12.1e01```, is unchanged. This will be converted into a Double.
This PR replaces the ```BigDecimal``` literal by a ```Double``` literal, because the ```BigDecimal``` is the default now. You can use the double literal by appending a 'D' to the value, for instance: ```3.141527D```
cc davies rxin
Author: Herman van Hovell <hvanhovell@questtec.nl>
Closes#10796 from hvanhovell/SPARK-12848.
The existing `Union` logical operator only supports two children. Thus, adding a new logical operator `Unions` which can have arbitrary number of children to replace the existing one.
`Union` logical plan is a binary node. However, a typical use case for union is to union a very large number of input sources (DataFrames, RDDs, or files). It is not uncommon to union hundreds of thousands of files. In this case, our optimizer can become very slow due to the large number of logical unions. We should change the Union logical plan to support an arbitrary number of children, and add a single rule in the optimizer to collapse all adjacent `Unions` into a single `Unions`. Note that this problem doesn't exist in physical plan, because the physical `Unions` already supports arbitrary number of children.
Author: gatorsmile <gatorsmile@gmail.com>
Author: xiaoli <lixiao1983@gmail.com>
Author: Xiao Li <xiaoli@Xiaos-MacBook-Pro.local>
Closes#10577 from gatorsmile/unionAllMultiChildren.
Currently, HiveTableScan runs with getCallSite which is really expensive and shows up when scanning through large table with partitions (e.g TPC-DS) which slows down the overall runtime of the job. It would be good to consider having dummyCallSite in HiveTableScan.
Author: Rajesh Balamohan <rbalamohan@apache.org>
Closes#10825 from rajeshbalamohan/SPARK-12898.
for normal parquet file without bucket, it's file name ends with a jobUUID which maybe all numbers and mistakeny regarded as bucket id. This PR improves the format of bucket id in file name by using a different seperator, `_`, so that the regex is more robust.
Author: Wenchen Fan <wenchen@databricks.com>
Closes#10799 from cloud-fan/fix-bucket.
Based on discussions in #10801, I'm submitting a pull request to rename ParserDialect to ParserInterface.
Author: Reynold Xin <rxin@databricks.com>
Closes#10817 from rxin/SPARK-12889.
Right now, the bucket tests are kind of hard to understand, this PR simplifies them and add more commetns.
Author: Wenchen Fan <wenchen@databricks.com>
Closes#10813 from cloud-fan/bucket-comment.
This pull request removes the public developer parser API for external parsers. Given everything a parser depends on (e.g. logical plans and expressions) are internal and not stable, external parsers will break with every release of Spark. It is a bad idea to create the illusion that Spark actually supports pluggable parsers. In addition, this also reduces incentives for 3rd party projects to contribute parse improvements back to Spark.
Author: Reynold Xin <rxin@databricks.com>
Closes#10801 from rxin/SPARK-12855.
This is the initial work for whole stage codegen, it support Projection/Filter/Range, we will continue work on this to support more physical operators.
A micro benchmark show that a query with range, filter and projection could be 3X faster then before.
It's turned on by default. For a tree that have at least two chained plans, a WholeStageCodegen will be inserted into it, for example, the following plan
```
Limit 10
+- Project [(id#5L + 1) AS (id + 1)#6L]
+- Filter ((id#5L & 1) = 1)
+- Range 0, 1, 4, 10, [id#5L]
```
will be translated into
```
Limit 10
+- WholeStageCodegen
+- Project [(id#1L + 1) AS (id + 1)#2L]
+- Filter ((id#1L & 1) = 1)
+- Range 0, 1, 4, 10, [id#1L]
```
Here is the call graph to generate Java source for A and B (A support codegen, but B does not):
```
* WholeStageCodegen Plan A FakeInput Plan B
* =========================================================================
*
* -> execute()
* |
* doExecute() --------> produce()
* |
* doProduce() -------> produce()
* |
* doProduce() ---> execute()
* |
* consume()
* doConsume() ------------|
* |
* doConsume() <----- consume()
```
A SparkPlan that support codegen need to implement doProduce() and doConsume():
```
def doProduce(ctx: CodegenContext): (RDD[InternalRow], String)
def doConsume(ctx: CodegenContext, child: SparkPlan, input: Seq[ExprCode]): String
```
Author: Davies Liu <davies@databricks.com>
Closes#10735 from davies/whole2.
This PR adds the support to read bucketed tables, and correctly populate `outputPartitioning`, so that we can avoid shuffle for some cases.
TODO(follow-up PRs):
* bucket pruning
* avoid shuffle for bucketed table join when use any super-set of the bucketing key.
(we should re-visit it after https://issues.apache.org/jira/browse/SPARK-12704 is fixed)
* recognize hive bucketed table
Author: Wenchen Fan <wenchen@databricks.com>
Closes#10604 from cloud-fan/bucket-read.
In this PR the new CatalystQl parser stack reaches grammar parity with the old Parser-Combinator based SQL Parser. This PR also replaces all uses of the old Parser, and removes it from the code base.
Although the existing Hive and SQL parser dialects were mostly the same, some kinks had to be worked out:
- The SQL Parser allowed syntax like ```APPROXIMATE(0.01) COUNT(DISTINCT a)```. In order to make this work we needed to hardcode approximate operators in the parser, or we would have to create an approximate expression. ```APPROXIMATE_COUNT_DISTINCT(a, 0.01)``` would also do the job and is much easier to maintain. So, this PR **removes** this keyword.
- The old SQL Parser supports ```LIMIT``` clauses in nested queries. This is **not supported** anymore. See https://github.com/apache/spark/pull/10689 for the rationale for this.
- Hive has a charset name char set literal combination it supports, for instance the following expression ```_ISO-8859-1 0x4341464562616265``` would yield this string: ```CAFEbabe```. Hive will only allow charset names to start with an underscore. This is quite annoying in spark because as soon as you use a tuple names will start with an underscore. In this PR we **remove** this feature from the parser. It would be quite easy to implement such a feature as an Expression later on.
- Hive and the SQL Parser treat decimal literals differently. Hive will turn any decimal into a ```Double``` whereas the SQL Parser would convert a non-scientific decimal into a ```BigDecimal```, and would turn a scientific decimal into a Double. We follow Hive's behavior here. The new parser supports a big decimal literal, for instance: ```81923801.42BD```, which can be used when a big decimal is needed.
cc rxin viirya marmbrus yhuai cloud-fan
Author: Herman van Hovell <hvanhovell@questtec.nl>
Closes#10745 from hvanhovell/SPARK-12575-2.
This PR makes bucketing and exchange share one common hash algorithm, so that we can guarantee the data distribution is same between shuffle and bucketed data source, which enables us to only shuffle one side when join a bucketed table and a normal one.
This PR also fixes the tests that are broken by the new hash behaviour in shuffle.
Author: Wenchen Fan <wenchen@databricks.com>
Closes#10703 from cloud-fan/use-hash-expr-in-shuffle.
