[FLINK-12710] Unify built-in and user-defined functions in the API modules

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Implemented
• Component/s: Table SQL / API
• Labels: auto-unassigned pull-request-available
• Assignee: Unassigned
• Reporter: Timo Walther
• Created: 03/Jun/19 13:18
• Updated: 30/Apr/21 11:53
• Resolved: 30/Apr/21 11:53

Description

Currently, there are three completely different stacks of functions: Table API builtins, SQL builtins, and user-defined types.

Both the Blink and the legacy planner define a separate list of functions and implementations with different type system and type checking logic.

The long-term goal of this issue is to unify all 6 different stacks into a common one. This includes better support for type inference which relates to FLINK-12251.

Issue Links

• is a child of: FLINK-11448 Clean-up and prepare Table API to be uncoupled from table core
• relates to: FLINK-12251 Rework the Table API & SQL type system
• links to: GitHub Pull Request #8790

Sub-Tasks

• Separate function implementation and definition: Closed
• Introduce a resolved expression with data type: Closed