[CALCITE-292] Improve windowed aggregate return types

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.8
• Labels: github-import
• Assignee: Unassigned
• Reporter: GitHub Import
• Created: 18/Jun/14 09:03
• Updated: 25/Aug/14 19:08
• Resolved: 22/Jun/14 21:49

Description

Optiq currently makes all windowed aggregate functions nullable, but that is invalid. In many cases they will be `NOT NULL`.

For example:

• `RANK() OVER w` is not nullable;
• `FIRST_VALUE(deptno) OVER w` is nullable if and only if `deptno` is nullable;
• `SUM OVER w` is nullable iff x is nullable or w may be empty.

---------------- Imported from GitHub ----------------
Url: https://github.com/julianhyde/optiq/issues/292
Created by: julianhyde
Labels:
Created at: Tue May 27 21:09:38 CEST 2014
State: open