hsyuan

I am not sure, but should NEW have only 1 argument?

Orca doesn't support index on expressions or functions. https://github.com/greenplum-db/gporca/issues/311

So this is a known, unsupported feature.

But even with some data, it can still generate the subplan.

execution time of orca plan doubles planner plan for this data set.

Fixed by commit: https://github.com/greenplum-db/gporca/commit/cb1bfb59aec4f9ba56c711023343b7bdacaa27a7

the commit was reverted. so this issue still exists.

because the return type of `count` is `bigint`, not `int`.

maybe similar with #50

simpler repro: ```sql create table foo(a int, b int) distributed by (a); create table bar(c bigint, d bigint) distributed by (c); set optimizer=off; explain select * from foo, bar where...