## What changes were proposed in this pull request?
This PR proposes to add `to_json` function in contrast with `from_json` in Scala, Java and Python.
It'd be useful if we can convert a same column from/to json. Also, some datasources do not support nested types. If we are forced to save a dataframe into those data sources, we might be able to work around by this function.
The usage is as below:
``` scala
val df = Seq(Tuple1(Tuple1(1))).toDF("a")
df.select(to_json($"a").as("json")).show()
```
``` bash
+--------+
| json|
+--------+
|{"_1":1}|
+--------+
```
## How was this patch tested?
Unit tests in `JsonFunctionsSuite` and `JsonExpressionsSuite`.
Author: hyukjinkwon <gurwls223@gmail.com>
Closes#15354 from HyukjinKwon/SPARK-17764.
## What changes were proposed in this pull request?
Simplify struct creation, especially the aspect of `CleanupAliases` which missed some aliases when handling trees created by `CreateStruct`.
This PR includes:
1. A failing test (create struct with nested aliases, some of the aliases survive `CleanupAliases`).
2. A fix that transforms `CreateStruct` into a `CreateNamedStruct` constructor, effectively eliminating `CreateStruct` from all expression trees.
3. A `NamePlaceHolder` used by `CreateStruct` when column names cannot be extracted from unresolved `NamedExpression`.
4. A new Analyzer rule that resolves `NamePlaceHolder` into a string literal once the `NamedExpression` is resolved.
5. `CleanupAliases` code was simplified as it no longer has to deal with `CreateStruct`'s top level columns.
## How was this patch tested?
running all tests-suits in package org.apache.spark.sql, especially including the analysis suite, making sure added test initially fails, after applying suggested fix rerun the entire analysis package successfully.
modified few tests that expected `CreateStruct` which is now transformed into `CreateNamedStruct`.
Credit goes to hvanhovell for assisting with this PR.
Author: eyal farago <eyal farago>
Author: eyal farago <eyal.farago@gmail.com>
Author: Herman van Hovell <hvanhovell@databricks.com>
Author: Eyal Farago <eyal.farago@actimize.com>
Author: Hyukjin Kwon <gurwls223@gmail.com>
Author: eyalfa <eyal.farago@gmail.com>
Closes#14444 from eyalfa/SPARK-16839_redundant_aliases_after_cleanupAliases.
## What changes were proposed in this pull request?
We should follow hive table and also store partition spec in metastore for data source table.
This brings 2 benefits:
1. It's more flexible to manage the table data files, as users can use `ADD PARTITION`, `DROP PARTITION` and `RENAME PARTITION`
2. We don't need to cache all file status for data source table anymore.
## How was this patch tested?
existing tests.
Author: Eric Liang <ekl@databricks.com>
Author: Michael Allman <michael@videoamp.com>
Author: Eric Liang <ekhliang@gmail.com>
Author: Wenchen Fan <wenchen@databricks.com>
Closes#15515 from cloud-fan/partition.
## What changes were proposed in this pull request?
The `UnaryNode.getAliasedConstraints` function fails to replace all expressions by their alias where constraints contains more than one expression to be replaced.
For example:
```
val tr = LocalRelation('a.int, 'b.string, 'c.int)
val multiAlias = tr.where('a === 'c + 10).select('a.as('x), 'c.as('y))
multiAlias.analyze.constraints
```
currently outputs:
```
ExpressionSet(Seq(
IsNotNull(resolveColumn(multiAlias.analyze, "x")),
IsNotNull(resolveColumn(multiAlias.analyze, "y"))
)
```
The constraint `resolveColumn(multiAlias.analyze, "x") === resolveColumn(multiAlias.analyze, "y") + 10)` is missing.
## How was this patch tested?
Add new test cases in `ConstraintPropagationSuite`.
Author: jiangxingbo <jiangxb1987@gmail.com>
Closes#15597 from jiangxb1987/alias-constraints.
## What changes were proposed in this pull request?
The function `QueryPlan.inferAdditionalConstraints` and `UnaryNode.getAliasedConstraints` can produce a non-converging set of constraints for recursive functions. For instance, if we have two constraints of the form(where a is an alias):
`a = b, a = f(b, c)`
Applying both these rules in the next iteration would infer:
`f(b, c) = f(f(b, c), c)`
This process repeated, the iteration won't converge and the set of constraints will grow larger and larger until OOM.
~~To fix this problem, we collect alias from expressions and skip infer constraints if we are to transform an `Expression` to another which contains it.~~
To fix this problem, we apply additional check in `inferAdditionalConstraints`, when it's possible to generate recursive constraints, we skip generate that.
## How was this patch tested?
Add new testcase in `SQLQuerySuite`/`InferFiltersFromConstraintsSuite`.
Author: jiangxingbo <jiangxb1987@gmail.com>
Closes#15319 from jiangxb1987/constraints.
## What changes were proposed in this pull request?
The PR tries to fix [SPARK-18058](https://issues.apache.org/jira/browse/SPARK-18058) which refers to a bug that the column types are compared with the extra care about Nullability in Union and SetOperation.
This PR converts the columns types by setting all fields as nullable before comparison
## How was this patch tested?
regular unit test cases
Author: CodingCat <zhunansjtu@gmail.com>
Closes#15595 from CodingCat/SPARK-18058.
## What changes were proposed in this pull request?
`Array[T]()` -> `Array.empty[T]` to avoid allocating 0-length arrays.
Use regex `find . -name '*.scala' | xargs -i bash -c 'egrep "Array\[[A-Za-z]+\]\(\)" -n {} && echo {}'` to find modification candidates.
cc srowen
## How was this patch tested?
existing tests
Author: Zheng RuiFeng <ruifengz@foxmail.com>
Closes#15564 from zhengruifeng/avoid_0_length_array.
## What changes were proposed in this pull request?
Unlike Hive, in Spark SQL, ALTER TABLE RENAME TO cannot move a table from one database to another(e.g. `ALTER TABLE db1.tbl RENAME TO db2.tbl2`), and will report error if the database in source table and destination table is different. So in #14955 , we forbid users to specify database of destination table in ALTER TABLE RENAME TO, to be consistent with other database systems and also make it easier to rename tables in non-current database, e.g. users can write `ALTER TABLE db1.tbl RENAME TO tbl2`, instead of `ALTER TABLE db1.tbl RENAME TO db1.tbl2`.
However, this is a breaking change. Users may already have queries that specify database of destination table in ALTER TABLE RENAME TO.
This PR reverts most of #14955 , and simplify the usage of ALTER TABLE RENAME TO by making database of source table the default database of destination table, instead of current database, so that users can still write `ALTER TABLE db1.tbl RENAME TO tbl2`, which is consistent with other databases like MySQL, Postgres, etc.
## How was this patch tested?
The added back tests and some new tests.
Author: Wenchen Fan <wenchen@databricks.com>
Closes#15434 from cloud-fan/revert.
## What changes were proposed in this pull request?
Value classes were unsupported because catalyst data types were
obtained through reflection on erased types, which would resolve to a
value class' wrapped type and hence lead to unavailable methods during
code generation.
E.g. the following class
```scala
case class Foo(x: Int) extends AnyVal
```
would be seen as an `int` in catalyst and will cause instance cast failures when generated java code tries to treat it as a `Foo`.
This patch simply removes the erasure step when getting data types for
catalyst.
## How was this patch tested?
Additional tests in `ExpressionEncoderSuite`.
Author: Jakob Odersky <jakob@odersky.com>
Closes#15284 from jodersky/value-classes.
## What changes were proposed in this pull request?
This change adds a check in castToInterval method of Cast expression , such that if converted value is null , then isNull variable should be set to true.
Earlier, the expression Cast(Literal(), CalendarIntervalType) was throwing NullPointerException because of the above mentioned reason.
## How was this patch tested?
Added test case in CastSuite.scala
jira entry for detail: https://issues.apache.org/jira/browse/SPARK-17884
Author: prigarg <prigarg@adobe.com>
Closes#15449 from priyankagargnitk/SPARK-17884.
## What changes were proposed in this pull request?
Currently `Canonicalize` object doesn't support `And` and `Or`. So we can compare canonicalized form of predicates consistently. We should add the support.
## How was this patch tested?
Jenkins tests.
Author: Liang-Chi Hsieh <viirya@gmail.com>
Closes#15388 from viirya/canonicalize-and-or.
## What changes were proposed in this pull request?
Currently we use the same rule to parse top level and nested data fields. For example:
```
create table tbl_x(
id bigint,
nested struct<col1:string,col2:string>
)
```
Shows both syntaxes. In this PR we split this rule in a top-level and nested rule.
Before this PR,
```
sql("CREATE TABLE my_tab(column1: INT)")
```
works fine.
After this PR, it will throw a `ParseException`:
```
scala> sql("CREATE TABLE my_tab(column1: INT)")
org.apache.spark.sql.catalyst.parser.ParseException:
no viable alternative at input 'CREATE TABLE my_tab(column1:'(line 1, pos 27)
```
## How was this patch tested?
Add new testcases in `SparkSqlParserSuite`.
Author: jiangxingbo <jiangxb1987@gmail.com>
Closes#15346 from jiangxb1987/cdt.
## What changes were proposed in this pull request?
The `quotedString` method in `TableIdentifier` and `FunctionIdentifier` produce an illegal (un-parseable) name when the name contains a backtick. For example:
```
import org.apache.spark.sql.catalyst.parser.CatalystSqlParser._
import org.apache.spark.sql.catalyst.TableIdentifier
import org.apache.spark.sql.catalyst.analysis.UnresolvedAttribute
val complexName = TableIdentifier("`weird`table`name", Some("`d`b`1"))
parseTableIdentifier(complexName.unquotedString) // Does not work
parseTableIdentifier(complexName.quotedString) // Does not work
parseExpression(complexName.unquotedString) // Does not work
parseExpression(complexName.quotedString) // Does not work
```
We should handle the backtick properly to make `quotedString` parseable.
## How was this patch tested?
Add new testcases in `TableIdentifierParserSuite` and `ExpressionParserSuite`.
Author: jiangxingbo <jiangxb1987@gmail.com>
Closes#15403 from jiangxb1987/backtick.
## What changes were proposed in this pull request?
In practice we cannot guarantee that an `InternalRow` is immutable. This makes the `MutableRow` almost redundant. This PR folds `MutableRow` into `InternalRow`.
The code below illustrates the immutability issue with InternalRow:
```scala
import org.apache.spark.sql.catalyst.InternalRow
import org.apache.spark.sql.catalyst.expressions.GenericMutableRow
val struct = new GenericMutableRow(1)
val row = InternalRow(struct, 1)
println(row)
scala> [[null], 1]
struct.setInt(0, 42)
println(row)
scala> [[42], 1]
```
This might be somewhat controversial, so feedback is appreciated.
## How was this patch tested?
Existing tests.
Author: Herman van Hovell <hvanhovell@databricks.com>
Closes#15333 from hvanhovell/SPARK-17761.
## What changes were proposed in this pull request?
The result of the `Last` function can be wrong when the last partition processed is empty. It can return `null` instead of the expected value. For example, this can happen when we process partitions in the following order:
```
- Partition 1 [Row1, Row2]
- Partition 2 [Row3]
- Partition 3 []
```
In this case the `Last` function will currently return a null, instead of the value of `Row3`.
This PR fixes this by adding a `valueSet` flag to the `Last` function.
## How was this patch tested?
We only used end to end tests for `DeclarativeAggregateFunction`s. I have added an evaluator for these functions so we can tests them in catalyst. I have added a `LastTestSuite` to test the `Last` aggregate function.
Author: Herman van Hovell <hvanhovell@databricks.com>
Closes#15348 from hvanhovell/SPARK-17758.
## What changes were proposed in this pull request?
Currently Spark SQL parses regular decimal literals (e.g. `10.00`) as decimals and scientific decimal literals (e.g. `10.0e10`) as doubles. The difference between the two confuses most users. This PR unifies the parsing behavior and also parses scientific decimal literals as decimals.
This implications in tests are limited to a single Hive compatibility test.
## How was this patch tested?
Updated tests in `ExpressionParserSuite` and `SQLQueryTestSuite`.
Author: Herman van Hovell <hvanhovell@databricks.com>
Closes#14828 from hvanhovell/SPARK-17258.
## What changes were proposed in this pull request?
Code generation including too many mutable states exceeds JVM size limit to extract values from `references` into fields in the constructor.
We should split the generated extractions in the constructor into smaller functions.
## How was this patch tested?
I added some tests to check if the generated codes for the expressions exceed or not.
Author: Takuya UESHIN <ueshin@happy-camper.st>
Closes#15275 from ueshin/issues/SPARK-17702.
## What changes were proposed in this pull request?
We currently only allow relatively simple expressions as the input for a value based case statement. Expressions like `case (a > 1) or (b = 2) when true then 1 when false then 0 end` currently fail. This PR adds support for such expressions.
## How was this patch tested?
Added a test to the ExpressionParserSuite.
Author: Herman van Hovell <hvanhovell@databricks.com>
Closes#15322 from hvanhovell/SPARK-17753.
## What changes were proposed in this pull request?
Currently, Spark does not collapse adjacent windows with the same partitioning and sorting. This PR implements `CollapseWindow` optimizer to do the followings.
1. If the partition specs and order specs are the same, collapse into the parent.
2. If the partition specs are the same and one order spec is a prefix of the other, collapse to the more specific one.
For example:
```scala
val df = spark.range(1000).select($"id" % 100 as "grp", $"id", rand() as "col1", rand() as "col2")
// Add summary statistics for all columns
import org.apache.spark.sql.expressions.Window
val cols = Seq("id", "col1", "col2")
val window = Window.partitionBy($"grp").orderBy($"id")
val result = cols.foldLeft(df) { (base, name) =>
base.withColumn(s"${name}_avg", avg(col(name)).over(window))
.withColumn(s"${name}_stddev", stddev(col(name)).over(window))
.withColumn(s"${name}_min", min(col(name)).over(window))
.withColumn(s"${name}_max", max(col(name)).over(window))
}
```
**Before**
```scala
scala> result.explain
== Physical Plan ==
Window [max(col2#19) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col2_max#234], [grp#17L], [id#14L ASC NULLS FIRST]
+- Window [min(col2#19) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col2_min#216], [grp#17L], [id#14L ASC NULLS FIRST]
+- Window [stddev_samp(col2#19) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col2_stddev#191], [grp#17L], [id#14L ASC NULLS FIRST]
+- Window [avg(col2#19) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col2_avg#167], [grp#17L], [id#14L ASC NULLS FIRST]
+- Window [max(col1#18) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col1_max#152], [grp#17L], [id#14L ASC NULLS FIRST]
+- Window [min(col1#18) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col1_min#138], [grp#17L], [id#14L ASC NULLS FIRST]
+- Window [stddev_samp(col1#18) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col1_stddev#117], [grp#17L], [id#14L ASC NULLS FIRST]
+- Window [avg(col1#18) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col1_avg#97], [grp#17L], [id#14L ASC NULLS FIRST]
+- Window [max(id#14L) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS id_max#86L], [grp#17L], [id#14L ASC NULLS FIRST]
+- Window [min(id#14L) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS id_min#76L], [grp#17L], [id#14L ASC NULLS FIRST]
+- *Project [grp#17L, id#14L, col1#18, col2#19, id_avg#26, id_stddev#42]
+- Window [stddev_samp(_w0#59) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS id_stddev#42], [grp#17L], [id#14L ASC NULLS FIRST]
+- *Project [grp#17L, id#14L, col1#18, col2#19, id_avg#26, cast(id#14L as double) AS _w0#59]
+- Window [avg(id#14L) windowspecdefinition(grp#17L, id#14L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS id_avg#26], [grp#17L], [id#14L ASC NULLS FIRST]
+- *Sort [grp#17L ASC NULLS FIRST, id#14L ASC NULLS FIRST], false, 0
+- Exchange hashpartitioning(grp#17L, 200)
+- *Project [(id#14L % 100) AS grp#17L, id#14L, rand(-6329949029880411066) AS col1#18, rand(-7251358484380073081) AS col2#19]
+- *Range (0, 1000, step=1, splits=Some(8))
```
**After**
```scala
scala> result.explain
== Physical Plan ==
Window [max(col2#5) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col2_max#220, min(col2#5) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col2_min#202, stddev_samp(col2#5) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col2_stddev#177, avg(col2#5) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col2_avg#153, max(col1#4) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col1_max#138, min(col1#4) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col1_min#124, stddev_samp(col1#4) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col1_stddev#103, avg(col1#4) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS col1_avg#83, max(id#0L) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS id_max#72L, min(id#0L) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS id_min#62L], [grp#3L], [id#0L ASC NULLS FIRST]
+- *Project [grp#3L, id#0L, col1#4, col2#5, id_avg#12, id_stddev#28]
+- Window [stddev_samp(_w0#45) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS id_stddev#28], [grp#3L], [id#0L ASC NULLS FIRST]
+- *Project [grp#3L, id#0L, col1#4, col2#5, id_avg#12, cast(id#0L as double) AS _w0#45]
+- Window [avg(id#0L) windowspecdefinition(grp#3L, id#0L ASC NULLS FIRST, RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS id_avg#12], [grp#3L], [id#0L ASC NULLS FIRST]
+- *Sort [grp#3L ASC NULLS FIRST, id#0L ASC NULLS FIRST], false, 0
+- Exchange hashpartitioning(grp#3L, 200)
+- *Project [(id#0L % 100) AS grp#3L, id#0L, rand(6537478539664068821) AS col1#4, rand(-8961093871295252795) AS col2#5]
+- *Range (0, 1000, step=1, splits=Some(8))
```
## How was this patch tested?
Pass the Jenkins tests with a newly added testsuite.
Author: Dongjoon Hyun <dongjoon@apache.org>
Closes#15317 from dongjoon-hyun/SPARK-17739.
## What changes were proposed in this pull request?
Currently for `Union [Distinct]`, a `Distinct` operator is necessary to be on the top of `Union`. Once there are adjacent `Union [Distinct]`, there will be multiple `Distinct` in the query plan.
E.g.,
For a query like: select 1 a union select 2 b union select 3 c
Before this patch, its physical plan looks like:
*HashAggregate(keys=[a#13], functions=[])
+- Exchange hashpartitioning(a#13, 200)
+- *HashAggregate(keys=[a#13], functions=[])
+- Union
:- *HashAggregate(keys=[a#13], functions=[])
: +- Exchange hashpartitioning(a#13, 200)
: +- *HashAggregate(keys=[a#13], functions=[])
: +- Union
: :- *Project [1 AS a#13]
: : +- Scan OneRowRelation[]
: +- *Project [2 AS b#14]
: +- Scan OneRowRelation[]
+- *Project [3 AS c#15]
+- Scan OneRowRelation[]
Only the top distinct should be necessary.
After this patch, the physical plan looks like:
*HashAggregate(keys=[a#221], functions=[], output=[a#221])
+- Exchange hashpartitioning(a#221, 5)
+- *HashAggregate(keys=[a#221], functions=[], output=[a#221])
+- Union
:- *Project [1 AS a#221]
: +- Scan OneRowRelation[]
:- *Project [2 AS b#222]
: +- Scan OneRowRelation[]
+- *Project [3 AS c#223]
+- Scan OneRowRelation[]
## How was this patch tested?
Jenkins tests.
Author: Liang-Chi Hsieh <viirya@gmail.com>
Closes#15238 from viirya/remove-extra-distinct-union.
Spark SQL has great support for reading text files that contain JSON data. However, in many cases the JSON data is just one column amongst others. This is particularly true when reading from sources such as Kafka. This PR adds a new functions `from_json` that converts a string column into a nested `StructType` with a user specified schema.
Example usage:
```scala
val df = Seq("""{"a": 1}""").toDS()
val schema = new StructType().add("a", IntegerType)
df.select(from_json($"value", schema) as 'json) // => [json: <a: int>]
```
This PR adds support for java, scala and python. I leveraged our existing JSON parsing support by moving it into catalyst (so that we could define expressions using it). I left SQL out for now, because I'm not sure how users would specify a schema.
Author: Michael Armbrust <michael@databricks.com>
Closes#15274 from marmbrus/jsonParser.
## What changes were proposed in this pull request?
This patch fixes a minor correctness issue impacting the pushdown of filters beneath aggregates. Specifically, if a filter condition references no grouping or aggregate columns (e.g. `WHERE false`) then it would be incorrectly pushed beneath an aggregate.
Intuitively, the only case where you can push a filter beneath an aggregate is when that filter is deterministic and is defined over the grouping columns / expressions, since in that case the filter is acting to exclude entire groups from the query (like a `HAVING` clause). The existing code would only push deterministic filters beneath aggregates when all of the filter's references were grouping columns, but this logic missed the case where a filter has no references. For example, `WHERE false` is deterministic but is independent of the actual data.
This patch fixes this minor bug by adding a new check to ensure that we don't push filters beneath aggregates when those filters don't reference any columns.
## How was this patch tested?
New regression test in FilterPushdownSuite.
Author: Josh Rosen <joshrosen@databricks.com>
Closes#15289 from JoshRosen/SPARK-17712.
## What changes were proposed in this pull request?
This PR introduces more compact representation for ```UnsafeArrayData```.
```UnsafeArrayData``` needs to accept ```null``` value in each entry of an array. In the current version, it has three parts
```
[numElements] [offsets] [values]
```
`Offsets` has the number of `numElements`, and represents `null` if its value is negative. It may increase memory footprint, and introduces an indirection for accessing each of `values`.
This PR uses bitvectors to represent nullability for each element like `UnsafeRow`, and eliminates an indirection for accessing each element. The new ```UnsafeArrayData``` has four parts.
```
[numElements][null bits][values or offset&length][variable length portion]
```
In the `null bits` region, we store 1 bit per element, represents whether an element is null. Its total size is ceil(numElements / 8) bytes, and it is aligned to 8-byte boundaries.
In the `values or offset&length` region, we store the content of elements. For fields that hold fixed-length primitive types, such as long, double, or int, we store the value directly in the field. For fields with non-primitive or variable-length values, we store a relative offset (w.r.t. the base address of the array) that points to the beginning of the variable-length field and length (they are combined into a long). Each is word-aligned. For `variable length portion`, each is aligned to 8-byte boundaries.
The new format can reduce memory footprint and improve performance of accessing each element. An example of memory foot comparison:
1024x1024 elements integer array
Size of ```baseObject``` for ```UnsafeArrayData```: 8 + 1024x1024 + 1024x1024 = 2M bytes
Size of ```baseObject``` for ```UnsafeArrayData```: 8 + 1024x1024/8 + 1024x1024 = 1.25M bytes
In summary, we got 1.0-2.6x performance improvements over the code before applying this PR.
Here are performance results of [benchmark programs](04d2e4b6db/sql/core/src/test/scala/org/apache/spark/sql/execution/benchmark/UnsafeArrayDataBenchmark.scala):
**Read UnsafeArrayData**: 1.7x and 1.6x performance improvements over the code before applying this PR
````
OpenJDK 64-Bit Server VM 1.8.0_91-b14 on Linux 4.4.11-200.fc22.x86_64
Intel Xeon E3-12xx v2 (Ivy Bridge)
Without SPARK-15962
Read UnsafeArrayData: Best/Avg Time(ms) Rate(M/s) Per Row(ns) Relative
------------------------------------------------------------------------------------------------
Int 430 / 436 390.0 2.6 1.0X
Double 456 / 485 367.8 2.7 0.9X
With SPARK-15962
Read UnsafeArrayData: Best/Avg Time(ms) Rate(M/s) Per Row(ns) Relative
------------------------------------------------------------------------------------------------
Int 252 / 260 666.1 1.5 1.0X
Double 281 / 292 597.7 1.7 0.9X
````
**Write UnsafeArrayData**: 1.0x and 1.1x performance improvements over the code before applying this PR
````
OpenJDK 64-Bit Server VM 1.8.0_91-b14 on Linux 4.0.4-301.fc22.x86_64
Intel Xeon E3-12xx v2 (Ivy Bridge)
Without SPARK-15962
Write UnsafeArrayData: Best/Avg Time(ms) Rate(M/s) Per Row(ns) Relative
------------------------------------------------------------------------------------------------
Int 203 / 273 103.4 9.7 1.0X
Double 239 / 356 87.9 11.4 0.8X
With SPARK-15962
Write UnsafeArrayData: Best/Avg Time(ms) Rate(M/s) Per Row(ns) Relative
------------------------------------------------------------------------------------------------
Int 196 / 249 107.0 9.3 1.0X
Double 227 / 367 92.3 10.8 0.9X
````
**Get primitive array from UnsafeArrayData**: 2.6x and 1.6x performance improvements over the code before applying this PR
````
OpenJDK 64-Bit Server VM 1.8.0_91-b14 on Linux 4.0.4-301.fc22.x86_64
Intel Xeon E3-12xx v2 (Ivy Bridge)
Without SPARK-15962
Get primitive array from UnsafeArrayData: Best/Avg Time(ms) Rate(M/s) Per Row(ns) Relative
------------------------------------------------------------------------------------------------
Int 207 / 217 304.2 3.3 1.0X
Double 257 / 363 245.2 4.1 0.8X
With SPARK-15962
Get primitive array from UnsafeArrayData: Best/Avg Time(ms) Rate(M/s) Per Row(ns) Relative
------------------------------------------------------------------------------------------------
Int 151 / 198 415.8 2.4 1.0X
Double 214 / 394 293.6 3.4 0.7X
````
**Create UnsafeArrayData from primitive array**: 1.7x and 2.1x performance improvements over the code before applying this PR
````
OpenJDK 64-Bit Server VM 1.8.0_91-b14 on Linux 4.0.4-301.fc22.x86_64
Intel Xeon E3-12xx v2 (Ivy Bridge)
Without SPARK-15962
Create UnsafeArrayData from primitive array: Best/Avg Time(ms) Rate(M/s) Per Row(ns) Relative
------------------------------------------------------------------------------------------------
Int 340 / 385 185.1 5.4 1.0X
Double 479 / 705 131.3 7.6 0.7X
With SPARK-15962
Create UnsafeArrayData from primitive array: Best/Avg Time(ms) Rate(M/s) Per Row(ns) Relative
------------------------------------------------------------------------------------------------
Int 206 / 211 306.0 3.3 1.0X
Double 232 / 406 271.6 3.7 0.9X
````
1.7x and 1.4x performance improvements in [```UDTSerializationBenchmark```](https://github.com/apache/spark/blob/master/mllib/src/test/scala/org/apache/spark/mllib/linalg/UDTSerializationBenchmark.scala) over the code before applying this PR
````
OpenJDK 64-Bit Server VM 1.8.0_91-b14 on Linux 4.4.11-200.fc22.x86_64
Intel Xeon E3-12xx v2 (Ivy Bridge)
Without SPARK-15962
VectorUDT de/serialization: Best/Avg Time(ms) Rate(M/s) Per Row(ns) Relative
------------------------------------------------------------------------------------------------
serialize 442 / 533 0.0 441927.1 1.0X
deserialize 217 / 274 0.0 217087.6 2.0X
With SPARK-15962
VectorUDT de/serialization: Best/Avg Time(ms) Rate(M/s) Per Row(ns) Relative
------------------------------------------------------------------------------------------------
serialize 265 / 318 0.0 265138.5 1.0X
deserialize 155 / 197 0.0 154611.4 1.7X
````
## How was this patch tested?
Added unit tests into ```UnsafeArraySuite```
Author: Kazuaki Ishizaki <ishizaki@jp.ibm.com>
Closes#13680 from kiszk/SPARK-15962.
## What changes were proposed in this pull request?
We currently cannot execute an aggregate that contains a single distinct aggregate function and an one or more non-partially plannable aggregate functions, for example:
```sql
select grp,
collect_list(col1),
count(distinct col2)
from tbl_a
group by 1
```
This is a regression from Spark 1.6. This is caused by the fact that the single distinct aggregation code path assumes that all aggregates can be planned in two phases (is partially aggregatable). This PR works around this issue by triggering the `RewriteDistinctAggregates` in such cases (this is similar to the approach taken in 1.6).
## How was this patch tested?
Created `RewriteDistinctAggregatesSuite` which checks if the aggregates with distinct aggregate functions get rewritten into two `Aggregates` and an `Expand`. Added a regression test to `DataFrameAggregateSuite`.
Author: Herman van Hovell <hvanhovell@databricks.com>
Closes#15187 from hvanhovell/SPARK-17616.
## What changes were proposed in this pull request?
After #15054 , there is no place in Spark SQL that need `SessionCatalog.tableExists` to check temp views, so this PR makes `SessionCatalog.tableExists` only check permanent table/view and removes some hacks.
This PR also improves the `getTempViewOrPermanentTableMetadata` that is introduced in #15054 , to make the code simpler.
## How was this patch tested?
existing tests
Author: Wenchen Fan <wenchen@databricks.com>
Closes#15160 from cloud-fan/exists.
## What changes were proposed in this pull request?
Floor()/Ceil() of decimal is implemented using changePrecision() by passing a rounding mode, but the rounding mode is not respected when the decimal is in compact mode (could fit within a Long).
This Update the changePrecision() to respect rounding mode, which could be ROUND_FLOOR, ROUND_CEIL, ROUND_HALF_UP, ROUND_HALF_EVEN.
## How was this patch tested?
Added regression tests.
Author: Davies Liu <davies@databricks.com>
Closes#15154 from davies/decimal_round.
## What changes were proposed in this pull request?
Remainder(%) expression's `eval()` returns incorrect result when the dividend is a big double. The reason is that Remainder converts the double dividend to decimal to do "%", and that lose precision.
This bug only affects the `eval()` that is used by constant folding, the codegen path is not impacted.
### Before change
```
scala> -5083676433652386516D % 10
res2: Double = -6.0
scala> spark.sql("select -5083676433652386516D % 10 as a").show
+---+
| a|
+---+
|0.0|
+---+
```
### After change
```
scala> spark.sql("select -5083676433652386516D % 10 as a").show
+----+
| a|
+----+
|-6.0|
+----+
```
## How was this patch tested?
Unit test.
Author: Sean Zhong <seanzhong@databricks.com>
Closes#15171 from clockfly/SPARK-17617.
### What changes were proposed in this pull request?
- When the permanent tables/views do not exist but the temporary view exists, the expected error should be `NoSuchTableException` for partition-related ALTER TABLE commands. However, it always reports a confusing error message. For example,
```
Partition spec is invalid. The spec (a, b) must match the partition spec () defined in table '`testview`';
```
- When the permanent tables/views do not exist but the temporary view exists, the expected error should be `NoSuchTableException` for `ALTER TABLE ... UNSET TBLPROPERTIES`. However, it reports a missing table property. For example,
```
Attempted to unset non-existent property 'p' in table '`testView`';
```
- When `ANALYZE TABLE` is called on a view or a temporary view, we should issue an error message. However, it reports a strange error:
```
ANALYZE TABLE is not supported for Project
```
- When inserting into a temporary view that is generated from `Range`, we will get the following error message:
```
assertion failed: No plan for 'InsertIntoTable Range (0, 10, step=1, splits=Some(1)), false, false
+- Project [1 AS 1#20]
+- OneRowRelation$
```
This PR is to fix the above four issues.
### How was this patch tested?
Added multiple test cases
Author: gatorsmile <gatorsmile@gmail.com>
Closes#15054 from gatorsmile/tempViewDDL.
This patch addresses a corner-case escaping bug where field names which contain special characters were unsafely interpolated into error message string literals in generated Java code, leading to compilation errors.
This patch addresses these issues by using `addReferenceObj` to store the error messages as string fields rather than inline string constants.
Author: Josh Rosen <joshrosen@databricks.com>
Closes#15156 from JoshRosen/SPARK-17160.
## What changes were proposed in this pull request?
In `ExpressionEvalHelper`, we check the equality between two double values by comparing whether the expected value is within the range [target - tolerance, target + tolerance], but this can cause a negative false when the compared numerics are very large.
Before：
```
val1 = 1.6358558070241E306
val2 = 1.6358558070240974E306
ExpressionEvalHelper.compareResults(val1, val2)
false
```
In fact, `val1` and `val2` are but with different precisions, we should tolerant this case by comparing with percentage range, eg.,expected is within range [target - target * tolerance_percentage, target + target * tolerance_percentage].
After:
```
val1 = 1.6358558070241E306
val2 = 1.6358558070240974E306
ExpressionEvalHelper.compareResults(val1, val2)
true
```
## How was this patch tested?
Exsiting testcases.
Author: jiangxingbo <jiangxb1987@gmail.com>
Closes#15059 from jiangxb1987/deq.
## What changes were proposed in this pull request?
In `SessionCatalog`, we have several operations(`tableExists`, `dropTable`, `loopupRelation`, etc) that handle both temp views and metastore tables/views. This brings some bugs to DDL commands that want to handle temp view only or metastore table/view only. These bugs are:
1. `CREATE TABLE USING` will fail if a same-name temp view exists
2. `Catalog.dropTempView`will un-cache and drop metastore table if a same-name table exists
3. `saveAsTable` will fail or have unexpected behaviour if a same-name temp view exists.
These bug fixes are pulled out from https://github.com/apache/spark/pull/14962 and targets both master and 2.0 branch
## How was this patch tested?
new regression tests
Author: Wenchen Fan <wenchen@databricks.com>
Closes#15099 from cloud-fan/fix-view.
## What changes were proposed in this pull request?
This PR is a follow up of SPARK-17356. Current implementation of `TreeNode.toJSON` recursively converts all fields of TreeNode to JSON, even if the field is of type `Seq` or type Map. This may trigger out of memory exception in cases like:
1. the Seq or Map can be very big. Converting them to JSON may take huge memory, which may trigger out of memory error.
2. Some user space input may also be propagated to the Plan. The user space input can be of arbitrary type, and may also be self-referencing. Trying to print user space input to JSON may trigger out of memory error or stack overflow error.
For a code example, please check the Jira description of SPARK-17426.
In this PR, we refactor the `TreeNode.toJSON` so that we only convert a field to JSON string if the field is a safe type.
## How was this patch tested?
Unit test.
Author: Sean Zhong <seanzhong@databricks.com>
Closes#14990 from clockfly/json_oom2.
## What changes were proposed in this pull request?
The Antlr lexer we use to tokenize a SQL string may wrongly tokenize a fully qualified identifier as a decimal number token. For example, table identifier `default.123_table` is wrongly tokenized as
```
default // Matches lexer rule IDENTIFIER
.123 // Matches lexer rule DECIMAL_VALUE
_TABLE // Matches lexer rule IDENTIFIER
```
The correct tokenization for `default.123_table` should be:
```
default // Matches lexer rule IDENTIFIER,
. // Matches a single dot
123_TABLE // Matches lexer rule IDENTIFIER
```
This PR fix the Antlr grammar so that it can tokenize fully qualified identifier correctly:
1. Fully qualified table name can be parsed correctly. For example, `select * from database.123_suffix`.
2. Fully qualified column name can be parsed correctly, for example `select a.123_suffix from a`.
### Before change
#### Case 1: Failed to parse fully qualified column name
```
scala> spark.sql("select a.123_column from a").show
org.apache.spark.sql.catalyst.parser.ParseException:
extraneous input '.123' expecting {<EOF>,
...
, IDENTIFIER, BACKQUOTED_IDENTIFIER}(line 1, pos 8)
== SQL ==
select a.123_column from a
--------^^^
```
#### Case 2: Failed to parse fully qualified table name
```
scala> spark.sql("select * from default.123_table")
org.apache.spark.sql.catalyst.parser.ParseException:
extraneous input '.123' expecting {<EOF>,
...
IDENTIFIER, BACKQUOTED_IDENTIFIER}(line 1, pos 21)
== SQL ==
select * from default.123_table
---------------------^^^
```
### After Change
#### Case 1: fully qualified column name, no ParseException thrown
```
scala> spark.sql("select a.123_column from a").show
```
#### Case 2: fully qualified table name, no ParseException thrown
```
scala> spark.sql("select * from default.123_table")
```
## How was this patch tested?
Unit test.
Author: Sean Zhong <seanzhong@databricks.com>
Closes#15006 from clockfly/SPARK-17364.
## What changes were proposed in this pull request?
This PR fixes an issue with aggregates that have an empty input, and use a literals as their grouping keys. These aggregates are currently interpreted as aggregates **without** grouping keys, this triggers the ungrouped code path (which aways returns a single row).
This PR fixes the `RemoveLiteralFromGroupExpressions` optimizer rule, which changes the semantics of the Aggregate by eliminating all literal grouping keys.
## How was this patch tested?
Added tests to `SQLQueryTestSuite`.
Author: Herman van Hovell <hvanhovell@databricks.com>
Closes#15101 from hvanhovell/SPARK-17114-3.
## What changes were proposed in this pull request?
This PR has the appendRowUntilExceedingPageSize test in RowBasedKeyValueBatchSuite use whatever spark.buffer.pageSize value a user has specified to prevent a test failure for anyone testing Apache Spark on a box with a reduced page size. The test is currently hardcoded to use the default page size which is 64 MB so this minor PR is a test improvement
## How was this patch tested?
Existing unit tests with 1 MB page size and with 64 MB (the default) page size
Author: Adam Roberts <aroberts@uk.ibm.com>
Closes#15079 from a-roberts/patch-5.
### What changes were proposed in this pull request?
As explained in https://github.com/apache/spark/pull/14797:
>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.
We should not optimize the query in CTAS more than once. For example,
```Scala
spark.range(99, 101).createOrReplaceTempView("tab1")
val sqlStmt = "SELECT id, cast(id as long) * cast('1.0' as decimal(38, 18)) as num FROM tab1"
sql(s"CREATE TABLE tab2 USING PARQUET AS $sqlStmt")
checkAnswer(spark.table("tab2"), sql(sqlStmt))
```
Before this PR, the results do not match
```
== Results ==
!== Correct Answer - 2 == == Spark Answer - 2 ==
![100,100.000000000000000000] [100,null]
[99,99.000000000000000000] [99,99.000000000000000000]
```
After this PR, the results match.
```
+---+----------------------+
|id |num |
+---+----------------------+
|99 |99.000000000000000000 |
|100|100.000000000000000000|
+---+----------------------+
```
In this PR, we do not treat the `query` in CTAS as a child. Thus, the `query` will not be optimized when optimizing CTAS statement. However, we still need to analyze it for normalizing and verifying the CTAS in the Analyzer. Thus, we do it in the analyzer rule `PreprocessDDL`, because so far only this rule needs the analyzed plan of the `query`.
### How was this patch tested?
Added a test
Author: gatorsmile <gatorsmile@gmail.com>
Closes#15048 from gatorsmile/ctasOptimized.
## What changes were proposed in this pull request?
In `ReorderAssociativeOperator` rule, we extract foldable expressions with Add/Multiply arithmetics, and replace with eval literal. For example, `(a + 1) + (b + 2)` is optimized to `(a + b + 3)` by this rule.
For aggregate operator, output expressions should be derived from groupingExpressions, current implemenation of `ReorderAssociativeOperator` rule may break this promise. A instance could be:
```
SELECT
((t1.a + 1) + (t2.a + 2)) AS out_col
FROM
testdata2 AS t1
INNER JOIN
testdata2 AS t2
ON
(t1.a = t2.a)
GROUP BY (t1.a + 1), (t2.a + 2)
```
`((t1.a + 1) + (t2.a + 2))` is optimized to `(t1.a + t2.a + 3)`, which could not be derived from `ExpressionSet((t1.a +1), (t2.a + 2))`.
Maybe we should improve the rule of `ReorderAssociativeOperator` by adding a GroupingExpressionSet to keep Aggregate.groupingExpressions, and respect these expressions during the optimize stage.
## How was this patch tested?
Add new test case in `ReorderAssociativeOperatorSuite`.
Author: jiangxingbo <jiangxb1987@gmail.com>
Closes#14917 from jiangxb1987/rao.
## What changes were proposed in this pull request?
This PR build on #14976 and fixes a correctness bug that would cause the wrong quantile to be returned for small target errors.
## How was this patch tested?
This PR adds 8 unit tests that were failing without the fix.
Author: Timothy Hunter <timhunter@databricks.com>
Author: Sean Owen <sowen@cloudera.com>
Closes#15002 from thunterdb/ml-1783.
## 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.
## 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.
## 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.
## 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.
## 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.
## 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.
## 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.
## 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.
## 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.
### 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.
