Re: How to tune SQL to avoid ORA-03232 ?

From: David Cressey <david_at_dcressey.com>
Date: Wed, 16 Oct 2002 17:25:14 GMT
Message-ID: <_hhr9.194$0I3.16267@petpeeve.ziplink.net>

> >The CBO is not perfect. And I love to mess about wringing every drop of
> >performance I can from my Oracle SQL. :-)
>
> Oh ye of little faith! Of course it's perfect! It was, after all,
written by
> Oracle. :)

Actually, much of the CBO was derived from algorithms that were part of DEC Rdb, when Oracle bought DEC Rdb in 1994. The original coding of the optimizer in DEC Rdb was done by DEC engineers, and it was some of the best engineering that has ever been done in this area. It may have been reprogrammed by Oracle for the RDBMS engine, but it's really an adaptation of ideas inherent in DEC Rdb.

The CBO is less than perfect, but it's possible to get it to outperform the RBO in all but a very few cases. And once you get used to it, you'll wonder how you ever lived without it. However.... the same thing was once said about the mouse and GUI, and before that about FORTRAN or COBOL. Plus ca change... Received on Wed Oct 16 2002 - 12:25:14 CDT