Re: is this an appropriate case for parallel processing?

"Antoine BRUNEL" <antoinebrunel/yahoo.fr> wrote in message news:3ec681a2$0$12994$79c14f64_at_nan-newsreader-03.noos.net...
> Hi from Paris
>
> and unfortunately, I think you should try ... even in the worst case, you
> won't get much performance degradation.
>
> Update the 'init.ora' to place PARALLEL_MAX/MIN_SERVER to reasonnable
values
> (don't hesitate to put high values for max, even more than number of
CPUs),
> cause several sessions could use slave processes.
>
>
> Then, ensure tables / index degree of parallelism is > 0, and your SQL
will
> use it:
> - either by specifying hint PARALLEL
> - more dangerous, at the instance level, set OPTIMIZER_PERCENT_PARALLEL
>
> In my point of view, if think PQO won't help for segments less than 1 Go
> ....
>
> You will have to ensure IO is not a bottleneck, and your CPU are really
> idles...
>
> PQO is a VERY specific option, and must be wisely used in order to get
> results.... much than people could think of
>
>
> "Ryan" <rgaffuri_at_cox.net> a écrit dans le message de
> news:a%cxa.18856$823.18445_at_news1.east.cox.net...
> > We have an instance run in Oracle 8173 on a Solaris v5.8(yes I know its
> > antiquated) with 4 CPUs using a Network Appliance hard disk array.
> >
> > SQLLOAD into a staging tablespace. Insert append and a create table AS.
> >
> > We have 5-6 tables over 100 MBs and the largest is 1GB. We have up to 73
> > tables that we have to batch process in a night. We rarely run all of
them
> > and about 40 of them are less than 10MBs some less than 100k.
> >
> > I was thinking of using parallel inserts,create table as,parallel index
> > building, parallel in a hash_aj we need to do. Im also going to use
> DBMS_JOB
> > to create indices, since talbes have multiple indices, if I run them
with
> > DBMS_JOB I can do all of them at the same time.
> >
> > how do I determine whether parallel processing will suck up too many
> > resources? Cant run it and see what happens because it has to succeed. I
> can
> > test it on a Saturday, but Id prefer not to blow a Saturday if this is
> > totally going in the wrong direction.
> >
> > We currently have MAX Slaves set to 5, and Threads per CPU set to 2. Not
> too
> > familiar with Parallel queries. Just started looking at it.
> >
> > Anyone have any advice on this?
> >
> >
>

All of our tables and indices are in the same datafile. However, Im doing HASH_AJs on large table of up to 1GB in size and up to 20 million rows. Will parallelism help with this kind of sorting in memory?

Any downside to setting a high MAX Slaves? Ill have to get the server bounced and I dont want to do it if there are negatives. Any suggestion on an appropriate setting?

>
Received on Sat May 17 2003 - 14:01:21 CDT