On 2016-04-26 12:39:37 +0900, Michael Paquier wrote: > Thinking about the logging of smgr invalidations, this is quite > interesting. But what would we actually gain in doing that? Do you > foresee any advantages in doing so? The only case where this would be > useful now is for vm_extend by looking at the code.
Well, it'd make vm_extend actually correct, which replacing the invalidation with a relcache one would not. Relcache invalidations are transactional, whereas smgr ones are not (intentionally so!). I don't think it's currently a big problem, but it does make me rather wary. > >> As the invalidation patch is aimed at being backpatched, this may be > >> something to do as well in back-branches. > > > > I'm a bit split here. I think forcing processing of invalidations at > > moments they've previously never been processed is a bit risky for the > > back branches. But on the other hand relcache invalidations are only > > processed at end-of-xact, which isn't really correct for the code at > > hand :/ > > Oh, OK. So you mean that this patch is not aimed for back-branches > with this new record type, but that's only for HEAD. No, I think we got to do this in all branches. I was just wondering about how to fix vm_extend(). Which I do think we got to fix, even in the back-branches. - Andres -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
