On Fri, Apr 7, 2023 at 09:55:00PM -0400, Tom Lane wrote: > Bruce Momjian <br...@momjian.us> writes: > > What I don't want is an error-prone setup where administrators have to > > remember what the per-server settings are. Based on your suggestion, > > let's allow CREATE SERVER to have an option 'enable_async_aggregate' (is > > that the right name?), which defaults to 'true' for _all_ servers, even > > those that don't support async aggregates. > > Uh, what? Why would we not be able to tell from the remote server's > version number whether it has this ability?
That was covered here: https://www.postgresql.org/message-id/ZC95C0%2BPVhVP3iax%40momjian.us I think we have three possible cases for aggregate pushdown to FDWs: 1) Postgres built-in aggregate functions 2) Postgres user-defined & extension aggregate functions 3) aggregate functions calls to non-PG FDWs Your patch handles #1 by checking that the FDW Postgres version is the --> same as the calling Postgres version. However, it doesn't check for --> extension versions, and frankly, I don't see how we could implement that --> cleanly without significant complexity. The issue is not a mismatch of postgres_fdw versions but the extension versions and whether the partial aggregate functions exist on the remote side, e.g., something like a PostGIS upgrade. -- Bruce Momjian <br...@momjian.us> https://momjian.us EDB https://enterprisedb.com Embrace your flaws. They make you human, rather than perfect, which you will never be.