dssysolyatin commented on code in PR #4022:
URL: https://github.com/apache/calcite/pull/4022#discussion_r1820961267
##########
core/src/main/java/org/apache/calcite/rel/rules/SubQueryRemoveRule.java:
##########
@@ -170,6 +170,13 @@ private static RexNode rewriteCollection(RexSubQuery e,
*/
private static RexNode rewriteSome(RexSubQuery e, Set<CorrelationId>
variablesSet,
RelBuilder builder, int subQueryIndex) {
+ // If the sub-query is guaranteed to return 0 row, just return
+ // FALSE.
+ final RelMetadataQuery mq = e.rel.getCluster().getMetadataQuery();
+ final Double maxRowCount = mq.getMaxRowCount(e.rel);
+ if (maxRowCount != null && maxRowCount < 1D) {
Review Comment:
Are you sure that maxRowCount < 1D guarantees that the subquery will return
zero records?
Since maxRowCount is a Double, I think if maxRowCount = 0.7, there is a
possibility that it could return more than 0 records.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
