Re: flushing the db buffer cache

On Thu, 12 Feb 1998 22:45:57 -0500, "Tom Mahoney" <mahoneyt_at_ntr.net> wrote:

>I want to be able to flush the db buffer cache when I am doing tuning.
>I thinks I can do it like so:
>select /*+ FULL(big) CACHE(big) */ count(*)
>from bigtable big;
>
>Where bigtable used space (highwater mark) > db_buffer_cache size.
>The explain plan shows that a full table scan is indeed used, but is the
>CACHE
>hint making it flush out any buffers not currently used? Or is it sticking
>to the
>multiblock_read_count (64k) part of the cache?
>
>PS. Don't try this on your production system ;-)
>

Tom,

AFAIK, Oracle won't cache (i.e. put them in top of LRU list) any blocks read by a full table scan.

HTH
Peter

-- 
Peter Schneider
peter.schneider_at_okay.net