v.22.9Improvement
Grouping Sets with group_by_use_nulls Affects Key Column Nullability
Grouping sets with group_by_use_nulls should only convert key columns to nullable. #40997 (Duc Canh Le).
Why it matters
This feature improves the handling of grouping sets when using thegroup_by_use_nulls setting by ensuring that only the key columns are converted to nullable types. This avoids unnecessary conversion of non-key columns, optimizing query performance and correctness when grouping with nulls.How to use it
Enable the feature by using thegroup_by_use_nulls setting in your query or session. This will automatically convert only the key columns to nullable when processing grouping sets. No additional user action is required beyond enabling this setting.