On Tue, Mar 21, 2017 at 8:18 PM, Peter Geoghegan <p...@bowt.ie> wrote: >> Not only might that be unnecessary, but if we don't have a test >> demonstrating the problem, we also don't have a test demonstrating >> that a given approach fixes it. > > Preventing recycling from happening until we feel like it is probably > fine. It is not fine to break it forever, though. The specific problem > is that there is an XID stored in dead B-Tree + SP-GiST pages that is > used in the subsequent RecentGlobalXmin interlock that determines if > recycling is safe (if there is no possible index scan that could land > on the dead page). You know, the _bt_page_recyclable() check.
Oh. OK, so this is not just about bloat -- it's about whether this can be safely done at all. Somehow, I missed that. -- Robert Haas EnterpriseDB: 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