Re: CBO optimizer

From: qwerty <qwerty_at_yahoo.it>
Date: Fri, 3 Dec 2004 19:11:47 +0100
Message-ID: <coqajn$bmc$1@lacerta.tiscalinet.it>

>>I know that oracle suggest to calculate statistics often and when is
>>known
>>that the data has changed a lot, but with my db, those statistcs take more
>>than 1hour to run (calculating them only on the dynamic tables).. which is
>>too much... I cannot wait such time before let the application work ...
>
> dbms_stats doesn't lock your tables. There is no reason why you would
> shutdown the application.
> I analyze a few Gig worth of data using dbms_stats in less than 15
> miutes, maybe your hardware is just too slow?

ok, but if a pl/sql code takes 1 second to execute with the right statistics, the same code takes 2 hour with the wrong statistcs, the dbms_stats doesn't lok the tables, but i CANNOT LET a user use the application in such circustances... Received on Fri Dec 03 2004 - 12:11:47 CST