On Mon, Aug 29, 2022 at 2:30 PM Richard Guo <guofengli...@gmail.com> wrote:
> > On Fri, Aug 19, 2022 at 2:45 AM Tom Lane <t...@sss.pgh.pa.us> wrote: > >> Here's a rebase up to HEAD, mainly to get the cfbot back in sync >> as to what's the live patch. > > > Noticed another different behavior from previous. When we try to reduce > JOIN_LEFT to JOIN_ANTI, we want to know if the join's own quals are > strict for any Var that was forced null by higher qual levels. We do > that by checking whether local_nonnullable_vars and forced_null_vars > overlap. However, the same Var from local_nonnullable_vars and > forced_null_vars may be labeled with different varnullingrels. If that > is the case, currently we would fail to tell they actually overlap. > I wonder why this is not noticed by regression tests. So I did some search and it seems we do not have any test cases covering the transformation we apply to reduce outer joins. I think maybe we should add such cases in regression tests. Thanks Richard
