"[email protected]" <[email protected]> writes:
> The 13.4 release notes document the following:
> > Fix mis-planning of repeated application of a projection step (Tom Lane)
> >
> > The planner could create an incorrect plan in cases where two
> > ProjectionPaths were stacked on top of each other. The only known
> > way to trigger that situation involves parallel sort operations,
> > but there may be other instances. The result would be crashes or
> > incorrect query results. Disclosure of server memory contents is also
> > possible. (CVE-2021-3677)
> >
> Is there a way to detect if this is happening and could this problem cause
> very bad, but successful, plans to be created? We are seeing 13.3 create
> horrible plans for some queries, where 13.4 creates great plans for the same
> queries.
No, whatever you're seeing, it was not this particular bug.
regards, tom lane
