[FLINK-21579] Support "SHOW USER FUNCTIONS" statement

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.13.0
• Component/s: Table SQL / API, Table SQL / Client
• Labels: pull-request-available
• Assignee: tim yu
• Reporter: Jark Wu
• Created: 03/Mar/21 08:06
• Updated: 15/Mar/21 14:33
• Resolved: 15/Mar/21 14:30

Description

Currently, the SHOW FUNCTIONS lists all user-defined and built-in functions which is very verbose. We already introduced listUserDefinedFunctions() method on TableEnvironment. I think we can introduce a dedicate syntax to show user-defined only functions which simply calls listUserDefinedFunctions(). That would be very useful.

I propose to use SHOW USER FUNCTIONS which is also supported by Snowflake [1] and Spark[2].

[1]: https://docs.snowflake.com/en/sql-reference/sql/show-user-functions.html
[2]: https://docs.databricks.com/spark/latest/spark-sql/language-manual/sql-ref-syntax-aux-show-functions.html

Issue Links

• links to: GitHub Pull Request #15110