Re: 8i to 9i migration, performance issues

CBO is lots different (lots better) in 9i than 8i.

Pay special attention to your method_opt setting when you use DBMS_STATS. You probably shouldn't use method_opt=>NULL. See asktom.oracle.com for more information.

--Cary

"More" <Newyorkboy1_at_aol.com> wrote in message news:afff1705.0403120733.22d99b33_at_posting.google.com...
> Do we loose features of 9i, if we set this parameter?
> optimizer_feature_enable=817
>
> CBO in 9i is different then CBO in 8i?
>
> Thanks,
>
> rjp.l_at_laposte.net (rjp) wrote in message
news:<9b7a7215.0403120057.3199bf13_at_posting.google.com>...
> > Hi,
> >
> > Yes, this problem occurs frequently.
> > - One way is to add the parameter optimizer_feature_enable=817 to
> > force the CBO to work like the 8i way.
> > - You should use 'DBMS_STAT' instead 'analyze schema' or
> > 'DBMS_UTILITY.ANALYZE_SCHEMA'
> >
> > rjp
> >
> > rohitk1973_at_yahoo.com (rohit) wrote in message
news:<74353ecc.0403110805.4e42475e_at_posting.google.com>...
> > > this ones a lollypop for most...
> > > we migrated 8i to 9i, 9.2.0.3.0. All the objects were moved, the
> > > server configuration remains identical. After this migration a lot of
> > > reports and pl/sql are taking a lot longer than they were before, and
> > > the execution plan is not abnormal in any way. What's missing......
> > > RK
Received on Sun Mar 14 2004 - 01:35:47 CST