0aa2c284e4
### What changes were proposed in this pull request?
This PR extends the current function registry and catalog to support table-valued functions by adding a table function registry. It also refactors `range` to be a built-in function in the table function registry.
### Why are the changes needed?
Currently, Spark resolves table-valued functions very differently from the other functions. This change is to make the behavior for table and non-table functions consistent. It also allows Spark to display information about built-in table-valued functions:
Before:
```scala
scala> sql("describe function range").show(false)
+--------------------------+
|function_desc |
+--------------------------+
|Function: range not found.|
+--------------------------+
```
After:
```scala
Function: range
Class: org.apache.spark.sql.catalyst.plans.logical.Range
Usage:
range(start: Long, end: Long, step: Long, numPartitions: Int)
range(start: Long, end: Long, step: Long)
range(start: Long, end: Long)
range(end: Long)
// Extended
Function: range
Class: org.apache.spark.sql.catalyst.plans.logical.Range
Usage:
range(start: Long, end: Long, step: Long, numPartitions: Int)
range(start: Long, end: Long, step: Long)
range(start: Long, end: Long)
range(end: Long)
Extended Usage:
Examples:
> SELECT * FROM range(1);
+---+
| id|
+---+
| 0|
+---+
> SELECT * FROM range(0, 2);
+---+
|id |
+---+
|0 |
|1 |
+---+
> SELECT range(0, 4, 2);
+---+
|id |
+---+
|0 |
|2 |
+---+
Since: 2.0.0
```
### Does this PR introduce _any_ user-facing change?
Yes. User will not be able to create a function with name `range` in the default database:
Before:
```scala
scala> sql("create function range as 'range'")
res3: org.apache.spark.sql.DataFrame = []
```
After:
```
scala> sql("create function range as 'range'")
org.apache.spark.sql.catalyst.analysis.FunctionAlreadyExistsException: Function 'default.range' already exists in database 'default'
```
### How was this patch tested?
Unit test
Closes #31791 from allisonwang-db/spark-34678-table-func-registry.
Authored-by: allisonwang-db <66282705+allisonwang-db@users.noreply.github.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
|
||
|---|---|---|
| .. | ||
| catalyst | ||
| core | ||
| hive | ||
| hive-thriftserver | ||
| create-docs.sh | ||
| gen-sql-api-docs.py | ||
| gen-sql-config-docs.py | ||
| gen-sql-functions-docs.py | ||
| mkdocs.yml | ||
| README.md | ||
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.