Re: MVCC catalog access

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'tbe done by default, but I'd love something like a function that would make a "snapshot" of all stats data as of
onepoint. Even if that snapshot itself wasn't completely atomic, at least then you could query any stats views however
youwanted 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
completebackend-local copy of pg_proc etc and the stats file would be orders of magnitude faster than a bunch of CREATE
TEMPTABLE's.
 
-- 
Jim C. Nasby, Data Architect                       jim@nasby.net
512.569.9461 (cell)                         http://jim.nasby.net