Re: flushing the db buffer cache

You may want to look at the init.ora parameter cache_size_threshhold, which defaults to 10% of db_block_buffers. This is a failsafe value so you don't accidentally flood the whole data buffer cache. Of course in your case this is what you want to do.

>>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 ;-)
Received on Mon Feb 16 1998 - 00:00:00 CST