Re: Init.ora .. OPTIMIZER parm: optimizer_index_cost_adj

This parameter tells the optimizer how much weight to give to indexes when evaluating a query. That's the short answer, it's really more complicated than that. A client I have uses a value of 4 for this parameter. This was arrived at using the old fashion method of changing the value and running some test queries and capturing timings for them.

>>> bruce.taneja_at_mcd.com 01/30/01 03:41PM >>>

Has any one messed with
optimizer_index_cost_adj
on 8.1.7 ??

The default is 100, but my boss thinks 10 is a better value for Cost based Opmtzr.. doesn't make any sense to me.. why would reducing the cost of using an optimizer make it more CBO or go faster.. what if its a large table?

Is it a good strategy to reduce this value to 10 or so ..

any one played with this on a 30GB database ? or any other size db?

thanks, Bruce

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com 
-- 
Author: 
  INET: bruce.taneja_at_mcd.com 

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).

--
Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: Tim Sawmiller
  INET: sawmillert_at_state.mi.us

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).