chaotian

more discussions at here https://jira.eng.vmware.com/browse/GPSERVER-195

origin issue: https://github.com/greenplum-db/gpdb/issues/10462#ref-pullrequest-1279149517

> > If someone who doesn't like DQA agg path could just turn-off guc gp_enable_agg_distinct, and optimizer > > will choose two stage agg path instead. > > Would you...

> The description is hard to be understood, because of not only the complexity of the problem, but also the description style...I'd suggest to reword in some ways: > >...

> The rest of the subselect should not contain correlated vars. @fishtree1161 I think subselect could contain correlated vars, but as you said **The On-Clause of Right Join refer to...

>whereClause contain correlated vars, and all correlated vars should refer to available_rels. Just like what EXISTS did. Got it, I understand your idea. I list some scenarios after this patch...

> I found that correlated vars in targetlist (select) of sublink may not affect, we can convert them (exists do not bother the targetlist). What do you think about it....

https://dev.ci.gpdb.pivotal.io/teams/main/pipelines/gpdb-dev-left-on-semi-in_c-rocky8

> I see nothing but only Concourse CI page structure. Is there any tests failed about this PR? maybe you didn't have permission to check pipeline results, I'll paste here...

pipeline https://dev.ci.gpdb.pivotal.io/teams/main/pipelines/gpdb-dev-6x_mdqa-rocky8