Re: Benefits of Keep Pool

Howard,

I've used the KEEP pool for something just like this. We have a product that requires quick access via indexes for our GUI users, while at the same time there are full table/index scans going on in an optimization process in the background. Since we can't have the optimization flushing the GUI indexes from the pool, we put them in KEEP. We also don't want to put the optimization stuff into the RECYCLE pool because we need it to be cached too.

The whole thing works really well.

Mark Simmons
Sr. Oracle DBA
Sabre-Holdings, Southlake, TX

"Howard J. Rogers" <hjr_at_dizwell.com> wrote in message news:<404ede7a$0$3952$afc38c87_at_news.optusnet.com.au>...
> "NetComrade" <netcomrade_at_karlson.dmitriev.net> wrote in message
> news:slrnc4plad.4h5.netcomrade_at_karlson.dmitriev.net...
> > Hi,
> >
> > What are the benefits of the Keep Pool in an OLTP environment?
> > The table is going to be cached anyway, if accessed frequently.
> > Will it help any latch contention?
> >
> > oracle 8.1.7.4/solaris 2.7
> >
>
> By virtue of the fact that defining a new buffer pool requires that you
> allocate it some latches, and that to do so you might end up increasing the
> total number of latches allocated to the buffer cache, it is possible that
> latch contention issues might be helped by having separate pools -though
> fundamentally, merely re-distrubuting the same number of latches between
> different pools isn't going to help at all.
>
> But the real idea is that you have a separate area of the buffer cache from
> which a table cannot be dislodged by a huge full table scan, because those
> full table scans will be busy flushing out their own area of the buffer
> cache, namely the recycle pool.
>
> Regards
> HJR
Received on Wed Mar 10 2004 - 14:05:47 CST