"HF" <h.frisch_at_uq.edu.au> wrote in message
news:d98bm1$1ifg$1_at_bunyip2.cc.uq.edu.au...
> Hi,
>
> If there are no system statistics generated for a 9i database, does the
> CBO use some sort of default values to calculate cost of queries?
>
> Thankyou.
>
>
>
In the absence of system statistics, Oracle
behaves as if the MBRC is a modified value
of db_file_multiblock_read_count, with
mreadtim = sreadtim, ignoring any cost of CPU
--
Regards
Jonathan Lewis
http://www.jlcomp.demon.co.uk/faq/ind_faq.html
The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/seminar.html
Public Appearances - schedule updated April 5th 2005
Received on Tue Jun 21 2005 - 03:14:17 CDT
