On Fri, Jan 27, 2023, 18:58 Andres Freund <and...@anarazel.de> wrote:
> Hi, > > On 2023-01-27 16:15:08 +1300, Thomas Munro wrote: > > It would be pg_current_xact_id() that would have to pay the cost of > > the WAL flush, not pg_xact_status() itself, but yeah that's what the > > patch does (with some optimisations). I guess one question is whether > > there are any other reasonable real world uses of > > pg_current_xact_id(), other than the original goal[1]. > > txid_current() is a lot older than pg_current_xact_id(), and they're > backed by > the same code afaict. 8.4 I think. > > Unfortunately txid_current() is used in plenty montiring setups IME. > > I don't think it's a good idea to make a function that was quite cheap for > 15 > years, suddenly be several orders of magnitude more expensive... As someone working on a monitoring tool that uses it (well, both), +1. We'd have to rethink a few things if this becomes a performance concern. Thanks, Maciek
