On Sat, Jan 14, 2012 at 5:42 AM, Robert Haas <robertmh...@gmail.com> wrote:
> Other than that, it seems like we might be converging on a workable > solution: if hot_standby_feedback=off, disable index-only scans for > snapshots taken during recovery; if hot_standby_feedback=on, generate > recovery conflicts when a snapshot's xmin precedes the youngest xmin > on a page marked all-visible, but allow the use of index-only scans, > and allow sequential scans to trust PD_ALL_VISIBLE. Off the top of my > head, I don't see a hole in that logic... Please use the logic described earlier. Using the existing mechanisms and infrastructure is all we need here. We want latestRemovedXid, not a new version of it via xmins. Keep index-only scans enabled all the time and let conflicts be generated. There are already mechanisms in place to handle conflicts, so avoiding them another way is not required or desired. -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, 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
