I haven't run any tests to prove this, but I was told by Someone Who Should
Know (a certfied Oracle Instructor) that CBO can't optimize a query any
better than a _properly_ optimized RBO query. If that is true, and one is
adept at optimizing RBO, then why go to CBO (except for reallly certain
cases such as large queries that are too time consuming to optimize
manually)? Just asking, not trying to make a point...
"Domenic G." <domenicg_at_hotmail.com> wrote in message
news:c7e08a19.0309111612.69697120_at_posting.google.com...
> I don't know about all of you, but I'm fed up with being a DBA and
> working in the IT industry. I've been an Oracle DBA for several years
> now and pride myself on knowing Oracle like the back of my hand.
>
> Here are my gripes ...
>
> - third party apps that run on Oracle and designed like junk.
> - third party apps that insist on "GRANT DBA TO ..."
> - schemas with FKs that aren't indexed (man do I hate that!)
> - poorly written queries (EXISTS and IN are like cryptonite!)
> - the COST based optimizer which outsmarts itself more often than not
> so that I have to to /*+ ORDERED INDEX(a b) USE_NL (w x y z) */ to
> achieve the same thing as /*+ RULE */
> - schemas that still use CHAR(x)
> - DBAs who use DBCA to create a DB and it adds in all that unwanted
> JUNK!!
>
> Cheers ...
> Domenic
Received on Fri Sep 12 2003 - 13:48:10 CDT
