Re: caching table/query

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.