Re: MVCC catalog access

On Thu, Jun 6, 2013 at 2:48 PM, Jim Nasby <jim(at)nasby(dot)net> wrote:
> On 6/5/13 3:49 PM, Robert Haas wrote:
>>
>> Now, I did find a couple that I thought should probably stick with
>> SnapshotNow, specifically pgrowlocks and pgstattuple.
>
> FWIW, I've often wished for a way to make all stat access transactional,
> across all the stats views. Perhaps that couldn't be done by default, but
> I'd love something like a function that would make a "snapshot" of all stats
> data as of one point. Even if that snapshot itself wasn't completely atomic,
> at least then you could query any stats views however you wanted and know
> that the info wasn't changing over time.
>
> The reason I don't think this would work so well if done in userspace is how
> long it would take. Presumably making a complete backend-local copy of
> pg_proc etc and the stats file would be orders of magnitude faster than a
> bunch of CREATE TEMP TABLE's.

Well, maybe. But at any rate this is completely unrelated to the main
topic of this thread. :-)

--
Robert Haas
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