[CALCITE-4241] Some improvements to metadata query - ASF JIRA

Rank to Top

Rank to Bottom

Bulk Copy Attachments

Bulk Move Attachments

Voters

Watch issue

Watchers

Convert to sub-task

Link

Clone

Update Comment Author

Replace String in Comment

Update Comment Visibility

Delete Comments

XML

Word

Printable

JSON

For {{RelMdColumnUniqueness#areColumnsUnique(RelSubset, RelMetadataQuery,
ImmutableBitSet, boolean)}}, we can return early as we encounter the first null.
For {{RelMdDistinctRowCount#getDistinctRowCount(Values, RelMetadataQuery,
ImmutableBitSet, RexNode)}}, we can get the distinct row count accurately, instead of guessing that half of the elements are distinct.
RelMdUtil#areColumnsDefinitelyUniqueWhenNullsFiltered could be implemented in a more efficient way.