Alvaro Herrera <alvhe...@2ndquadrant.com> wrote: > Bruce Momjian wrote:
>> I agree this is a serious problem. We have discussed various options, >> but have not decided on anything. The TODO list has: >> >> https://wiki.postgresql.org/wiki/Todo >> >> Improve setting of visibility map bits for read-only and insert-only >> workloads >> >> http://www.postgresql.org/message-id/20130906001437.ga29...@momjian.us > > I hate to repeat myself, but I think autovacuum could be modified to run > actions other than vacuum and analyze. In this specific case we could > be running a table scan that checks only pages that don't have the > all-visible bit set, and see if it can be set. (Of course, this idea > needs refinement to avoid running over and over when the bit cannot be > set on some pages for whatever reason.) Wouldn't we get substantially the same thing just by counting tuple inserts toward the autovacuum vacuum threshold? I mean, it unless the table is due for wraparound prevention autovacuum, it will only visit pages that don't have the all-visible bit set, right? And how much work would that do beyond what you're describing if none of the tuples are dead? -- Kevin Grittner EDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers