On Fri, 2023-01-27 at 16:15 +1300, Thomas Munro wrote: > On Fri, Jan 27, 2023 at 3:04 PM Tom Lane <t...@sss.pgh.pa.us> wrote: > > Thomas Munro <thomas.mu...@gmail.com> writes: > > > On Fri, Jan 27, 2023 at 1:30 PM Michael Paquier <mich...@paquier.xyz> > > > wrote: > > > > My opinion would be to make this function more reliable, FWIW, even if > > > > that involves a performance impact when called in a close loop by > > > > forcing more WAL flushes to ensure its report durability and > > > > consistency. > > > > > Yeah, the other thread has a patch for that. But it would hurt some > > > workloads. > > > > I think we need to get the thing correct first and worry about > > performance later. What's wrong with simply making pg_xact_status > > write and flush a record of the XID's existence before returning it? > > Yeah, it will cost you if you use that function, but not if you don't. > > There is no > doubt that the current situation is unacceptable, though, so maybe we > really should just do it and make a faster one later. Anyone else > want to vote on this?
I wasn't aware of the existence of pg_xact_status, so I suspect that it is not a widely known and used feature. After reading the documentation, I'd say that anybody who uses it will want it to give a reliable answer. So I'd agree that it is better to make it more expensive, but live up to its promise. Yours, Laurenz Albe
