SQL Tuning question

From: Ryan Gaffuri <rgaffuri_at_cox.net>
Date: 17 Jan 2003 05:00:48 -0800
Message-ID: <1efdad5b.0301170500.148f1cdc@posting.google.com>

First off, my explanation is going to be a bit vague since I dont have alot of details. However, I hope its enough to get an opinion.

I was talking to a couple of DBA's and on their project they stated that they often have to use a hint to force the RBO. They said that this happens when querying off of layered views. My best guess on why this is so, is that the analyzer will gather statistics off the tables, these statistics may not be entirely valid for views made on top of views, so when the CBO is used, it is using poor statistics.

I have seen in some books that if this happens you should consider re-writing your queries so that they directly access the tables. This could be very time consuming.

Just looking for some general comments on this? Received on Fri Jan 17 2003 - 07:00:48 CST