[FLINK-13191] Add a simplified UDF type extraction

• Type: New Feature
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: Table SQL / API
• Assignee: Timo Walther
• Reporter: Timo Walther
• Created: 10/Jul/19 09:42
• Updated: 13/Apr/21 05:46

Description

Currently, the input, accumulator, and output types of UDFs are partially defined within an UDF and outside of the UDF in language-specific table environments (Scala vs. Java). This makes UDFs environment-dependent and not modular. It also blocks the unified org.apache.flink.table.api.TableEnvironment.

A better approach is to perform the type extraction Table API specific within the UDF and let users add additional information through UDF annotations.

An exact annotation and extraction design will follow.

Issue Links

• causes: FLINK-20747 ClassCastException when using MAX aggregate function
• relates to: FLINK-16268 Failed to run rank over window with Hive built-in functions
• mentioned in: Page Loading...
• mentioned in: Page Loading...

Sub-Tasks

• Support the new type inference in Scala Table API aggregate functions: Open
• Update test utilities to FLIP-65: Open
• Drop old user-defined function stack: Open
• Use upper case name for all BuiltInFunctionDefinitions: Open
• TableEnvironment.createTemporarySystemFunction cause NPE when using leftOuterLateralJoin: Open
• Update max aggregate functions to new type system: Open