Query Optimization in Oracle

From: Goh Cheng Hian <chgoh_at_alum.mit.edu>
Date: Sat, 19 Sep 1998 10:30:45 +0800
Message-ID: <36031755.3B38ADDD@alum.mit.edu>

When choosing a query plan in Oracle, the number of buffers available needs to be
known to choose an optimal plan. In general, this is not known at the time when the
plan is chosen. I suppose that Oracle picks a default number. However, during
execuation time, there may be more buffers available. The question is will Oracle then allocate more of these buffers, or does it simply use what is presumed earlier.

Conversely, if less buffers are available, does it go ahead with the less buffers
or will the job not be scheduled at all.

Please cc a copy of reply to my email address at chgoh_at_alum.mit.edu. Thanks in advance.

Regards,
Cheng Received on Fri Sep 18 1998 - 21:30:45 CDT