On Wed, Aug 28, 2024 at 5:52 AM Tom Lane <t...@sss.pgh.pa.us> wrote: > I realized that actually we do have the mechanism for making that > work: we could apply add_nulling_relids to the expression, if it > meets those same conditions.
I think this should work, as long as we apply add_nulling_relids only to Vars/PHVs that belong to the subquery in this case, because only those Vars/PHVs would be nulled by the outer joins contained in the nullingrels. > If we go forward with this, I'm thinking about > changing add_nulling_relids' API contract to say "if target_relid > is NULL then all level-zero Vars/PHVs are modified", so that we > don't need that relid set in non-LATERAL cases. +1. In LATERAL case, we can always find the subquery's relids in rcon->relids. In non-lateral case, any level-zero Vars/PHVs must belong to the subquery - so if we change add_nulling_relids' API to be so, we do not need to have rcon->relids set. Thanks Richard
