spark-instrumented-optimizer/sql
Hyukjin Kwon 1d9f09decb [SPARK-35480][SQL] Make percentile_approx work with pivot
### What changes were proposed in this pull request?

This PR proposes to avoid wrapping if-else to the constant literals for `percentage` and `accuracy` in `percentile_approx`. They are expected to be literals (or foldable expressions).

Pivot works by two phrase aggregations, and it works with manipulating the input to `null` for non-matched values (pivot column and value).

Note that pivot supports an optimized version without such logic with changing input to `null` for some types (non-nested types basically). So the issue fixed by this PR is only for complex types.

```scala
val df = Seq(
  ("a", -1.0), ("a", 5.5), ("a", 2.5), ("b", 3.0), ("b", 5.2)).toDF("type", "value")
  .groupBy().pivot("type", Seq("a", "b")).agg(
    percentile_approx(col("value"), array(lit(0.5)), lit(10000)))
df.show()
```

**Before:**

```
org.apache.spark.sql.AnalysisException: cannot resolve 'percentile_approx((IF((type <=> CAST('a' AS STRING)), value, CAST(NULL AS DOUBLE))), (IF((type <=> CAST('a' AS STRING)), array(0.5D), NULL)), (IF((type <=> CAST('a' AS STRING)), 10000, CAST(NULL AS INT))))' due to data type mismatch: The accuracy or percentage provided must be a constant literal;
'Aggregate [percentile_approx(if ((type#7 <=> cast(a as string))) value#8 else cast(null as double), if ((type#7 <=> cast(a as string))) array(0.5) else cast(null as array<double>), if ((type#7 <=> cast(a as string))) 10000 else cast(null as int), 0, 0) AS a#16, percentile_approx(if ((type#7 <=> cast(b as string))) value#8 else cast(null as double), if ((type#7 <=> cast(b as string))) array(0.5) else cast(null as array<double>), if ((type#7 <=> cast(b as string))) 10000 else cast(null as int), 0, 0) AS b#18]
+- Project [_1#2 AS type#7, _2#3 AS value#8]
   +- LocalRelation [_1#2, _2#3]
```

**After:**

```
+-----+-----+
|    a|    b|
+-----+-----+
|[2.5]|[3.0]|
+-----+-----+
```

### Why are the changes needed?

To make percentile_approx work with pivot as expected

### Does this PR introduce _any_ user-facing change?

Yes. It threw an exception but now it returns a correct result as shown above.

### How was this patch tested?

Manually tested and unit test was added.

Closes #32619 from HyukjinKwon/SPARK-35480.

Authored-by: Hyukjin Kwon <gurwls223@apache.org>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
2021-05-23 07:35:43 +09:00
..
catalyst [SPARK-35480][SQL] Make percentile_approx work with pivot 2021-05-23 07:35:43 +09:00
core [SPARK-35480][SQL] Make percentile_approx work with pivot 2021-05-23 07:35:43 +09:00
hive [SPARK-28551][SQL][FOLLOWUP] Use the corrected hadoop conf 2021-05-22 10:33:57 +08:00
hive-thriftserver [SPARK-35286][SQL] Replace SessionState.start with SessionState.setCurrentSessionState 2021-05-16 18:39:15 +08:00
create-docs.sh [SPARK-34010][SQL][DODCS] Use python3 instead of python in SQL documentation build 2021-01-05 19:48:10 +09:00
gen-sql-api-docs.py [SPARK-34747][SQL][DOCS] Add virtual operators to the built-in function document 2021-03-19 10:19:26 +09:00
gen-sql-config-docs.py [SPARK-31550][SQL][DOCS] Set nondeterministic configurations with general meanings in sql configuration doc 2020-04-27 17:08:52 +09:00
gen-sql-functions-docs.py [SPARK-31562][SQL] Update ExpressionDescription for substring, current_date, and current_timestamp 2020-04-26 11:46:52 -07:00
mkdocs.yml [SPARK-30731] Update deprecated Mkdocs option 2020-02-19 17:28:58 +09:00
README.md [SPARK-30510][SQL][DOCS] Publicly document Spark SQL configuration options 2020-02-09 19:20:47 +09:00

Spark SQL

This module provides support for executing relational queries expressed in either SQL or the DataFrame/Dataset API.

Spark SQL is broken up into four subprojects:

  • Catalyst (sql/catalyst) - An implementation-agnostic framework for manipulating trees of relational operators and expressions.
  • Execution (sql/core) - A query planner / execution engine for translating Catalyst's logical query plans into Spark RDDs. This component also includes a new public interface, SQLContext, that allows users to execute SQL or LINQ statements against existing RDDs and Parquet files.
  • Hive Support (sql/hive) - Includes extensions that allow users to write queries using a subset of HiveQL and access data from a Hive Metastore using Hive SerDes. There are also wrappers that allow users to run queries that include Hive UDFs, UDAFs, and UDTFs.
  • HiveServer and CLI support (sql/hive-thriftserver) - Includes support for the SQL CLI (bin/spark-sql) and a HiveServer2 (for JDBC/ODBC) compatible server.

Running ./sql/create-docs.sh generates SQL documentation for built-in functions under sql/site, and SQL configuration documentation that gets included as part of configuration.md in the main docs directory.