On Tue, Aug 4, 2015 at 2:04 AM, Simon Riggs <[email protected]> wrote: > On 3 August 2015 at 17:36, Tom Lane <[email protected]> wrote: >> >> Alvaro Herrera <[email protected]> writes: >> > Simon Riggs wrote: >> >> * For emergency anti-wraparound VACUUMs we shouldn't scan indexes at >> >> all, >> >> since they aren't critical path activities at that point >> >> > It is not possible to skip scanning indexes completely, unless no tuples >> > are to be removed from the heap. >> >> Right. >> >> > But actually this is an interesting point and I don't think we do this: >> > if in emergency mode, maybe we shouldn't try to remove any dead tuples >> > at all, and instead only freeze very old tuples. >> >> +1 ... not sure if that's what Simon had in mind exactly, but it seems >> like a correct statement of what he was getting at. > > > Yes, that's what I was thinking, I just didn't say actually it. I'd been > thinking about having VACUUM do just Phase 1 for some time, since its so > much faster to do that. Will code.
Interesting. I'll be happy to have a look at any patch produced, that's surely something we want to improve in emergency mode. -- Michael -- Sent via pgsql-hackers mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
