[CALCITE-3666] Refine RelMdUniqueKeys and RelMdColumnUniqueness for Calc

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.21.0
• Fix Version/s: 1.22.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Vladimir Sitnikov
• Reporter: Vladimir Sitnikov
• Created: 02/Jan/20 13:18
• Updated: 23/Oct/24 10:15
• Resolved: 02/Jan/20 19:07

Description

RelMdColumnUniqueness does not have an override for Calc, thus it can't resolve uniqueness for EnumerableCalc

In practice, it is hard to deduce uniqueness for select emp.id*emp.deptno from emp, however, simple projects can be resolved (e.g. when Calc selects one of its input as is).

Issue Links

• causes: CALCITE-6640 RelMdUniqueKeys grows exponentially when key columns are repeated in projections
• is related to: HIVE-28582 OOM when compiling query with many GROUP BY columns aliased multiple times
• links to: GitHub Pull Request #1718