Re: parallel query and latch waits

I looks like the wait is on the cache buffers chains stats look like this
latches 1,024
gets/sec 126,085
 %gets 91.64
sleeps /sec 15.47 %
%sleeps 100
misses/sec 4,540
%misses 99.94

how do i find the
serial run time
parallel run time

"Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote in message news:991989083.8277.0.nnrp-14.9e984b29_at_news.demon.co.uk...
>
> Which version of Oracle.
>
> What is the
> serial run time
> parallel run time
> total wait time due to latches
>
> Which latches are responsible for most waits ?
>
>
>
> --
> Jonathan Lewis
> Yet another Oracle-related web site: http://www.jlcomp.demon.co.uk
>
> Practical Oracle 8i: Building Efficient Databases
> Publishers: Addison-Wesley
>
> Reviews at: http://www.jlcomp.demon.co.uk/book_rev.html
>
>
>
> Rob Katofiasc wrote in message ...
> >I have a table set up with parallel degree 4
> >the table is spread out across 4 physical disk mounts.
> >
> >Everything run great except if I have a subquery
> >
> >i.e.
> >
> >select sum(impressions)
> >from fact_table --parallel degree 4
> >where user_id in (select user_id
> > from users
> > where external_role_type IN('Named User', 'Registered
 User')
> > )
> >
> >latch waits are 60% of non-idle wait time (from spotlight)
> >What can I do to reduce this latch problem?
> >
> >If I remove parallel from the fact table I do not have a problem with
 latches?
> >
> >Thanks Rob
>
>
>
Received on Fri Jun 08 2001 - 11:16:04 CDT