Re: Making Vars outer-join aware

On Fri, Aug 19, 2022 at 2:45 AM Tom Lane <tgl@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.