[CALCITE-5944] Add metadata for Sample

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.36.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Jiajun Xie
• Reporter: Jiajun Xie
• Created: 20/Aug/23 09:15
• Updated: 10/Nov/23 11:34
• Resolved: 08/Sep/23 01:53

Description

For the sql

select * from emp tablesample system(20) 

`mq.getRowCount(rel)` is null, but we can return `inputRowCount * 0.2`.

 

Some metadata need to be implemented.

• RelMdAllPredicates
• RelMdColumnOrigins
• RelMdExpressionLineage
• RelMdMaxRowCount
• RelMdMinRowCount
• RelMdPredicates
• RelMdRowCount

Some metadata have been implemented.

• RelMdTableReferences
• RelMdNodeTypes

Some metadabata not need to be implemented.

• RelMdColumnUniqueness (Handle SingleRel)
• RelMdDistribution (Handle SingleRel)
• RelMdDistinctRowCount（Handle RelNode）
• RelMdExplainVisibility（Only TableScan）
• RelMdLowerBoundCost（Handle RelNode）
• RelMdMemory（Handle RelNode）
• RelMdParallelism（Handle RelNode）
• RelMdPercentageOriginalRows（Handle RelNode）
• RelMdPopulationSize（Handle RelNode）
• RelMdSelectivity（Must have predicate）
• RelMdSize（Handle RelNode）
• RelMdUniqueKeys（Handle SingleRel）

Issue Links

• links to: GitHub Pull Request #3382