Michael Fuhr wrote:
On Sun, Jul 17, 2005 at 02:00:28PM +0300, Tsirkin Evgeny wrote:
I have several pretty little tables (~300 - 400 records) which are
queried very frequently.
I would like to make postrgres be aware of this and do a in memory cache
for it .
PostgreSQL maintains a buffer cache in shared memory; if you enable
statistics gathering then you can see how effective it is for the
tables in question:
http://www.postgresql.org/docs/8.0/static/monitoring-stats.html
If the tables are small and you're querying them frequently, and
if shared_buffers is adequately sized, then I'd expect most or all
queries to be satisfied from the buffer cache. Those that aren't
might still be satisfied from the OS's cache.
Are you experiencing performance problems? Presumably that's the
real problem you're trying to solve.
Well, that is currently only development stage so i can't realy know if
there will be any perfomence problems.
But i am looking for a way to be sure i will not have one.And since i
already know what queries and tables i want
to cache those .Just saing to my boss " when we there will be
performance problems the postgresql will solve it "
would not do it.The case is that when runnig a test i am getting penalty
for requesting the table,of course the test
does query only once so i can't see the cache in work . What i realy
want is to say to postgres that the particular
table should be cached .
Thanks.
