Re: caching table/query

Well ,here is something that might be interesting:
trying to reduce query time and since that is a web application i now
using caching with
perl MLDBM::Sync::SDBM_File on application level .(Basically that
involves quering all the
table and putting it into MLDBM::Sync::SDBM_File and then quering it
back ) .What is
 interesting is that while  time quering the tables from postgres is
taken 0.3 sec. using sdbm
it takes 0.1 sec.
Actually i am not anymore sure that postgres does NOT cache table in memory,
maybe it does and i don't know about it?Maybe the time is spended in
transmitting the data
from postgres to the application? How can i test this?
Thanks.

Chris Travers wrote:

> Tsirkin Evgeny wrote:
>
>>
>> Well i guess that there are cases where that is not so.However i
>> understand that postgres does not have any way accept
>> the automatic.
>
>
> Largely true.  There may be ways of forcing a from-memory query once
> the system is in place, but I am not sure that this is always what you
> want, it would not be pretty, and might have some real performance
> issues.  My suggestion is that you wait until your system is in
> operation and then look first for general tuning help before you even
> consider trying to impliment a memory-cached table in your application.
>
> Just for the record, I can think of at least one way of hacking this
> on, but it seems like it should be an absolutely last resort rather
> than a first impulse.
>
> PostgreSQL can do this, but you probably don't want it to.
>
> Best Wishes,
> Chris Travers