On Thu, May 2, 2019 at 3:42 AM Alvaro Herrera <alvhe...@2ndquadrant.com> wrote: > > On 2019-May-01, Amit Kapila wrote: > > > On Tue, Apr 30, 2019 at 7:52 PM Alvaro Herrera <alvhe...@2ndquadrant.com> > > wrote: > > > > Hmm ... so, if vacuum runs and frees up any space from any of the pages, > > > then it should send out an invalidation -- it doesn't matter what the > > > FSM had, just that there is more free space now. That means every other > > > process will need to determine a fresh FSM, > > > > I think you intend to say the local space map because once FSM is > > created we will send invalidation and we won't further build relcache > > entry having local space map. > > Yeah, I mean the map that records free space. > > > > but that seems correct. Sounds better than keeping outdated entries > > > indicating no-space-available. > > > > Agreed, but as mentioned in one of the above emails, I am also bit > > scared that it should not lead to many invalidation messages for small > > relations, so may be we should send the invalidation message only when > > the entire page is empty. > > I don't think that's a concern, is it? You typically won't be running > multiple vacuums per second, or even multiple vacuums per minute. >
That's right. So let's try by adding invalidation call whenever space is reduced. Is there a good way to test whether the new invalidation calls added by this patch has any significant impact? -- With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com