Jonathan:
I guess starting from 9i there is a maximum size (for PGA) is defined
and the pga_max_size defaults to 200MB which can be changed using the
hidden parameter _pga_max_size.
I assume this could be the reason for improved (!) behaviour you see in
v9. I am not sure whether the limitations are applicable to earlier
versions unless you set the event 10261 to limit the PGA size.
KG
K Gopalakrishnan
Bangalore, INDIA
- Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk> wrote:
>
> Yes - at least in some cases.
>
> I don't think there is any way around problems
> of excessive disc activity, but v9 is much less
> profligate with memory.
>
> In a 6 table hash, for example, one possible path
> is to hash 5 tables in memory at once, then run the
> 6th through them. In this case, Oracle 8 MAY
> allocated 5 x hash_area_size - even if the five tables
> are very small. Oracle 9 will use a more appropriate
> allocation of memory, whether or not you are using
> the pga_aggregate_target.
>
> In a silly example, I saw Oracle 8 use something
> like 12MB of memory to hash a 4 row table - in
> circumstances where Oracle 9 used about 100K.
>
>
> (I assume this is a bug)
>
>
> Regards
>
> Jonathan Lewis
> http://www.jlcomp.demon.co.uk
>
> The educated person is not the person
> who can answer the questions, but the
> person who can question the answers -- T. Schick Jr
>
>
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>
> ----- Original Message -----
> To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com>
> Sent: 15 April 2003 04:08
> ???
>
>
> > You specifically mentioned Oracle 8 (inclusive of 8i I assume?).
> Does your
> > mention of 8 imply that 9i does a better job of exercising "damage
> > limitation"?
> >
> > Regards,
> >
> > Larry G. Elkins
> > elkinsl_at_flash.net
> > 214.954.1781
> >
>
>
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.net
> --
> Author: Jonathan Lewis
> INET: jonathan_at_jlcomp.demon.co.uk
>
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Have a nice day !!
Best Regards,
K Gopalakrishnan,
Bangalore, INDIA.
--
Please see the official ORACLE-L FAQ: http://www.orafaq.net
--
Author: K Gopalakrishnan
INET: kaygopal_at_yahoo.com
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Received on Tue Apr 15 2003 - 03:08:40 CDT
