Re: Database size Vs performance degradation

Dave North a écrit :
> [...]
>> I'd suggest re-tuning as follows:
>>
>> 1) Increase shared_buffers to 10,000, test. Things should be
>> a bit faster.
>>
>> 2) Increase checkpoint_segments to 30, test. What you want
>> to watch for here whether there are periods where the server
>> seems to freeze for a couple of seconds. That's a
>> "checkpoint spike". If this happens, reduce
>> checkpoint_segments to some sort of middle ground; some
>> people never get above 10 before it's a problem.
>>
>> 3) Increase shared_buffers in larger chunks, as long as you
>> don't see any problematic spikes you might usefully keep
>> going until it's set to at least 100,000 before improvements
>> level off.
>
> Do you happen to know if these are "reload" or "restart" tunable
> parameters? I think I've read somewhere before that they are restart
> parameters (assuming I've set SHMMAX high enough of course)
>

shared_buffers and checkpoint_segments both need a restart.
> [...]
> I have to say, I've learnt a whole load from you folks here this
> morning...very enlightening. I'm now moving on to your site Greg! :)
>

There's much to learn from Greg's site. I was kinda impressed by all the
good articles in it.

--
Guillaume.
http://www.postgresqlfr.org
http://dalibo.com