On Fri, Jul 19, 2013 at 12:29 PM, Alvaro Herrera <alvhe...@2ndquadrant.com> wrote: > Robert Haas escribió: >> On Fri, Jul 19, 2013 at 1:27 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: > >> > Why not tell people to use SnapshotDirty if they need a >> > not-guaranteed-consistent result? At least then it's pretty obvious >> > that you're getting some randomness in with your news. > >> On further reflection, I think perhaps pgrowlocks should just register >> a fresh MVCC snapshot and use that. Using SnapshotDirty would return >> TIDs of unseen tuples, which does not seem to be what is wanted there. > > I think seeing otherwise invisible rows is useful in pgrowlocks. It > helps observe the effects on tuples written by concurrent transactions > during experimentation. But then, maybe this functionality belongs in > pageinspect instead.
It does seem like it should be useful, at least as an option. But I feel like changing that ought to be separate from getting rid of SnapshotNow. It seems like too big of a behavior change to pass off as a harmless tweak. -- 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
