On Wed, Nov 23, 2011 at 9:44 PM, Simon Riggs <si...@2ndquadrant.com> wrote: > On Wed, Nov 23, 2011 at 3:20 PM, Alvaro Herrera > <alvhe...@commandprompt.com> wrote: >> >> Excerpts from Robert Haas's message of mié nov 23 12:15:55 -0300 2011: >> >>> > And it effects shared catalogs only, which are all low traffic anyway. >>> >>> I think "low traffic" is the key point. I understand that you're not >>> changing the VACUUM behavior, but you are making heap_page_prune_opt() >>> not do anything when a shared catalog is involved. That would be >>> unacceptable if we expected shared catalogs to be updated frequently, >>> either now or in the future, but I guess we don't expect that. >> >> Maybe not pg_database or pg_tablespace and such, but I'm not so sure >> about pg_shdepend. (Do we record pg_shdepend entries for temp tables?) > > Normal catalog access does not use HOT and never has. >
I don't understand that. We started with the simplified assumption that HOT can skip catalog tables, but later that was one of the pre-conditions Tom spelled out to accept HOT patch because his view was if this does not work for system tables, it probably does not work at all. Thanks, Pavan -- Pavan Deolasee EnterpriseDB http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers