On 6 September 2016 at 19:23, Robert Haas <robertmh...@gmail.com> wrote: > On Tue, Sep 6, 2016 at 2:16 PM, Simon Riggs <si...@2ndquadrant.com> wrote: >> What occurs to me is that we can exactly predict how many tuples we >> are going to get when we autovacuum, since we measure that and we know >> what the number is when we trigger it. >> >> So there doesn't need to be any guessing going on at all, nor do we >> need it to be flexible. > > No, that's not really true. A lot can change between the time it's > triggered and the time it happens, or even while it's happening. > Somebody can run a gigantic bulk delete just after we start the > VACUUM.
Which wouldn't be removed by the VACUUM, so can be ignored. -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
