[CALCITE-6427] Use a higher precision for DECIMAL intermediate results for some aggregate functions like STDDEV

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.37.0
• Fix Version/s: 1.38.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Unassigned
• Reporter: Mihai Budiu
• Created: 04/Jun/24 01:01
• Updated: 17/Oct/24 22:41
• Resolved: 17/Oct/24 22:41

Description

Today aggregates like STDDEV are expanded into computations that use intermediate results with the same type as the input values. Since STDDEV squares values, this precision may prove insufficient. For DECIMAL values a reasonable approach would be to use double the input precision and scale.

This is also related to CALCITE-6322, CALCITE-4924, CALCITE-6324

Issue Links

• relates to: CALCITE-6516 AVG to SUM+COUNT transformation inserts invalid CAST call
• links to: GitHub Pull Request #3809