On July 19, 2016 7:14:42 PM PDT, Amit Kapila <amit.kapil...@gmail.com> wrote: >On Wed, Jul 20, 2016 at 5:02 AM, Andres Freund <and...@anarazel.de> >wrote: >> On 2016-07-19 18:09:59 -0500, Kevin Grittner wrote: >>> As far as I can see, to do this the way that Andres and Amit >>> suggest involves tying in to indexam.c and other code in incredibly >>> ugly ways. >> >> Could you explain the problem you're seing? >> >> Isn't pretty much all all that we need to do: >> 1) add a InitSnapshotToast(Snapshot originMVCCSnap), which sets >SnapshotData->lsn >> to the the origin snapshot's lsn >> 2) adapt TestForOldSnapshot() to accept both HeapTupleSatisfiesMVCC >and >> HeapTupleSatisfiesToast? >> > >I also think so. However, it is not clear what is the best place to >initialize toast snapshot. One idea could be to do it in >GetSnapshotData() after capturing the required information for the >valid value of old_snapshot_threshold. Do you have something else in >mind?
There's very few callsites using toast snapshots. I'd just do it there. Don't think we ever use GetSnapshotData for them. Andres -- Sent from my Android device with K-9 Mail. Please excuse my brevity. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
