On Fri, Dec 14, 2012 at 6:46 AM, Andres Freund <and...@2ndquadrant.com> wrote: > Just moving that tidbit inside the lock seems to be the pragmatic > choice. GetOldestXmin is called > > * once per checkpoint > * one per index build > * once in analyze > * twice per vacuum > * once for HS feedback messages > > Nothing of that occurs frequently enough that 5 instructions will make a > difference. I would be happy to go an alternative path, but right now I > don't see any nice one. A "already_locked" parameter to GetOldestXmin > seems to be a cure worse than the disease.
I'm not sure that would be so bad, but I guess I question the need to do it this way at all. Most of the time, if you need to advertise your global xmin, you use GetSnapshotData(), not GetOldestXmin(), and I guess I'm not seeing why that wouldn't also work here. Am I dumb? -- 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
