[ http://issues.apache.org/jira/browse/DERBY-1681?page=all ]
A B reopened DERBY-1681: ------------------------ Reopening to update Fixin to include trunk (10.3) > Regression (wrong results): Join predicate can be ignored for left-most child > in a chain of nested unions. > ---------------------------------------------------------------------------------------------------------- > > Key: DERBY-1681 > URL: http://issues.apache.org/jira/browse/DERBY-1681 > Project: Derby > Issue Type: Bug > Components: SQL > Affects Versions: 10.1.3.1, 10.1.3.0, 10.2.1.0 > Reporter: A B > Assigned To: A B > Fix For: 10.2.1.0, 10.1.4.0 > > Attachments: d1681_test.patch, d1681_test_v2.patch, d1681_v1.patch, > DERBY-1681_v1.html > > > If Derby chooses to do a join between two FromTables and the right table is a > chain of UNIONs, then the optimizer may choose to push the join predicate (if > provided) down into the UNION and to both children of every UNION in the > chain. But if the predicate cannot be pushed to the children of any of the > UNIONs (except the top-level one) the predicate can end up being ignored > altogether with respect to that UNION's children. The result is that query > execution can return rows that do not satisfy the predicate. > This is a regression introduced in 10.1.2.4 and thus it affects 10.1.3 and > 10.2. I came across this while tracing through code for DERBY-1633. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira