Stephen Frost <sfrost@snowman.net> wrote:
> Andres Freund (andres@anarazel.de) wrote:
>> * Allow "snapshot too old" error, to prevent bloat
>> http://archives.postgresql.org/message-id/1361166406.1897609.1424371443904.JavaMail.yahoo%40mail.yahoo.com
>> talked about a new version that afaics never materialized
>> => Returned with feedback
>
> As mentioned earlier, this is a committer's patch and if Kevin
> shows up with a new patch based on that discussion which others
> can live with, then I'm for having the capability over not. As
> such, not sure if RFW is the right state for it to be in at this
> point.
Unfortunately, other emergencies have cut into my time for
finishing this for 9.5, and it seems more appropriate for a "start
of release cycle" patch than a "just before beta" patch; so look
for that in the first CF for the next release. (Of course, if
someone wants to run with it and wants to argue for 9.5, I'll do
what I can to ensure it is solid.)
The current status, as I see it, are that there are two things that
need to be done:
(1) The GUC needs to be changed from number of transactions to
time-based. This is partly done, and could probably be finished in
a couple full-time days.
(2) Every index AM needs to insert a TestForOldSnapshot() call
after each BufferGetPage() call which is used for a search or scan.
(Those used to position for inserts or other internal purposes
don't need this treatment.) The btree AM is already done, but no
other AM has been started.
--
Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company