Re: Fed Up with being a DBA

Domenic G. wrote:

>Daniel,
>
>You make some good points, but I'm not paid by the hour! DBCA is OK
>for beginners, but I like to use a script so that I can hit all the
>functionality. As for COST, of course it works great for
>function-based indexes, query rewrite, partitioning, bitmap-join
>indexes, but if I want a straight NL with index scans on the join keys
>with one index scan on the driving table, COST seems to outsmart
>itself more often than not. For skewed columns, it works great. The
>whole concept behind COST is to LEAN AWAY from indexes when you're
>joining entire tables. Still, RULE is useful is certain situations,
>and if Oracle decides to desupport it, I'll kill them. I was able to
>increase system performance on one DB 20 times by simply changing to
>RULE -- COST kept doing hash joins when only a few rows were selected
>and the column was indexed!!!
>
>Domenic.
>
>

Perhaps that's why that Oracle bus almost hit Larry yesterday. We can laugh now but it wasn't that funny when it happened.

But seriously ... RBO is already dead. Get over it. Personally I haven't used RBO for several years and would be hard pressed to find a query that worked better with RBO than with CBO provided a proper understanding of CBO and how to tune for it.

I wasn't just being ornry when I suggested you take a class ... I was serious. No doubt you've been in Oracle quite a long time and likely are still applying version 7.x and 8.0 lessons to 9i. That will stop being an option about two minutes after you have 10g.

Years after the release of 9i we still get posts here asking what happened to server manager (svrmgrl). It is not to hard to imagine ourselves three years from now fielding posts with questions such as "I tried to build a rollback segment and ...." or my soon to be favorite "how come I can't build a tablespace with the code I used in version X?" Don't become dinosaur ... evolve. ;-)

-- 
Daniel Morgan
http://www.outreach.washington.edu/ext/certificates/oad/oad_crs.asp
http://www.outreach.washington.edu/ext/certificates/aoa/aoa_crs.asp
damorgan_at_x.washington.edu
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