On Tue, Nov 21, 2017 at 11:32 AM, Merlin Moncure <mmonc...@gmail.com> wrote: >> I think that wouldn't work very well, because I think we must have a >> snapshot open in order to run pg_get_notifications(), and that means >> we're holding back the system-wide xmin. > > I am very much looking at the new stored procedure functionality and > imaging a loop like this: > > LOOP > FOR r IN SELECT * FROM pg_get_notifications(30) > > LOOP > PERFORM do_stuff(r); > END LOOP; > > COMMIT; -- advance xmin etc > END LOOP; > > ...I'm obviously speculatively thinking ahead to Peter's stored > procedure work seeing the light of day (which, based on the utility vs > the simplicity of the patch and how it works in testing I'm very > optimistic about). The above would provide real time response to > certain actions I do now with polling, typically in bash. Without > stored procedures, I agree that this would be a foot gun.
Yeah, if you keep the timeout fairly short, it would probably work OK (with Peter's stuff). -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
