On Wed, Dec 21, 2016 at 5:10 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: > If I thought that "every ten minutes" was an ideal way to manage this, > I might worry about that, but it doesn't really sound promising at all. > Every so many queries would likely work better, or better yet make it > self-adaptive depending on how much is in the local syscache. > > The bigger picture here though is that we used to have limits on syscache > size, and we got rid of them (commit 8b9bc234a, see also > https://www.postgresql.org/message-id/flat/5141.1150327541%40sss.pgh.pa.us) > not only because of the problem you mentioned about performance falling > off a cliff once the working-set size exceeded the arbitrary limit, but > also because enforcing the limit added significant overhead --- and did so > whether or not you got any benefit from it, ie even if the limit is never > reached. Maybe the present patch avoids imposing a pile of overhead in > situations where no pruning is needed, but it doesn't really look very > promising from that angle in a quick once-over.
Have there been ever discussions about having catcache entries in a shared memory area? This does not sound much performance-wise, I am just wondering about the concept and I cannot find references to such discussions. -- Michael -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
