[FLINK-9501] Allow Object or Wildcard type in user-define functions as parameter types but not result types

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Component/s: Table SQL / API
• Labels: auto-unassigned
• Assignee: Unassigned
• Reporter: Rong Rong
• Created: 01/Jun/18 23:25
• Updated: 30/Apr/21 03:53
• Resolved: 30/Apr/21 03:53

Description

Idea here is to treat every Java parameter objects type as SQL ANY type. While disallowing SQL ANY type in result object.
This ticket is specifically to deal with composite types (with nested schema or sub schema) such as generic erasure types

public String eval(Map<String, ?> mapArg) { /* ...  */ }
public String eval(Map<String, Object> mapArg) { /* ...  */ }
public String eval(Row rowArg) { /* ...  */ }

Update 08/2018
With FLINK-9294 covering some of the generic type erasure. The additional changes needed are:
1. Modify FunctionCatalog lookup to use SQL ANY type when a higher level type matching is not viable.
2. Introduce additional FunctionCatalog lookup checks to ensure that additional informations provided by type inference is used for validation purpose.