Re: Fed Up with being a DBA

Yeah, I started liking CBO a lot just after I learned to dump and interpret 10053 trace :)

Tanel.

"koert54" <nospam_at_spam.com> wrote in message news:dkq8b.4184755$cI2.590136_at_news.easynews.com...
> > Know (a certfied Oracle Instructor) that CBO can't optimize a query any
> > better than a _properly_ optimized RBO query. If that is true, and one
is
>
> personally I think that's BS - for one - RBO lacks a lot of features like
> function based index support,
> partition pruning ...
> Once you've set optimizer_index_cost_adj & optimizer_index_caching to
> values reflecting your
> environment RBO never beats CBO !!!
>
> "Alan" <alan_at_erols.com> wrote in message
> news:bjt4db$mouue$1_at_ID-114862.news.uni-berlin.de...
> > 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 - 20:54:46 CDT