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Re: SGA Free memory

From: Christo Kutrovsky <kutrovsky.oracle_at_gmail.com>
Date: Mon, 13 Feb 2006 14:20:04 -0500
Message-ID: <52a152eb0602131120y58f023bbl30bcd5c8544b2bfd@mail.gmail.com>


On a related note, have you guys noticed the very large memories on a "round" address with KSMCHCOM = 'permanent memor' and KSMCHCLS = 'perm' ?

SQL> select * from sys.x_$ksmsp where KSMCHCOM = 'permanent memor' and KSMCHCLS = 'perm' and ksmchsiz > 10000000;

ADDR                   INDX    INST_ID   KSMCHIDX   KSMCHDUR KSMCHCOM 
       KSMCHPTR           KSMCHSIZ KSMCHCLS   KSMCHTYP KSMCHPAR
---------------- ---------- ---------- ---------- ----------
---------------- ---------------- ---------- -------- ----------
----------------
0000002A97C66E18         13          1          1          1 permanent
memor  00000001BC0CD000   15899128 perm              0 00
0000002A97C669F8         25          1          1          1 permanent
memor  00000001BB0CD000   15596208 perm              0 00
0000002A97C66790         32          1          1          1 permanent
memor  00000001BA0CD000   15933896 perm              0 00
0000002A97C66370         44          1          1          1 permanent
memor  00000001B90CD000   15933896 perm              0 00
0000002A97C67388         90          1          1          1 permanent
memor  00000001B80CD000   13792800 perm              0 00
0000002A97C68A28        117          1          1          1 permanent
memor  00000001B70CD000   15902000 perm              0 00
0000002A97C68870        122          1          1          1 permanent
memor  00000001B60CD000   15851552 perm              0 00
0000002A97C68660        128          1          1          1 permanent
memor  00000001B50CD000   15109080 perm              0 00
0000002A97C68030        146          1          1          1 permanent
memor  00000001B40CD000   15886048 perm              0 00
0000002A97C692B0        185          1          1          1 permanent
memor  00000001B30CD000   14680096 perm              0 00
0000002A97BF2C78       6093          1          1          1 permanent
memor  00000001AF0CD000   15937376 perm              0 00

This looks to me like some kind of reserved memory, as I remember seeing a couple of these disappear in favor of other areas.

Jonathan what other articles would you recommend for shared pool insides ?

--
Christo Kutrovsky
Senior Database/System Administrator
The Pythian Group



On 2/11/06, Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk> wrote:

>
> Thanks for the reference - interesting paper.
>
> Regards
>
> Jonathan Lewis
> http://www.oracle.com/technology/community/oracle_ace/ace1.html#lewis
>
> The Co-operative Oracle Users' FAQ
> http://www.jlcomp.demon.co.uk/faq/ind_faq.html
>
> Cost Based Oracle: Fundamentals
> http://www.jlcomp.demon.co.uk/cbo_book/ind_book.html
>
>
> ----- Original Message -----
> From: "Luca Canali" <Luca.Canali_at_cern.ch>
> To: <oracle-l_at_freelists.org>
> Sent: Friday, February 10, 2006 8:15 AM
> Subject: RE: SGA Free memory
>
>
> Hi Jonathan,
>
> > loop
> > detach some items from end of library cache LRU
> > distribute items to shared pool free list - coalescing where
> possible
> > check for large enough chunk on free list
> > return if allocation succeeds
> > end loop
> >
> > There may be a limit on the number of times round the loop -
>
> Apparently the limit is 5 iterations (see Russell Green, OOW Sep. 2005)
>
> Regards,
> Luca
>
> -----------
> Luca Canali
> Information Technology Department
> European Organization for Nuclear Research
> CERN
> CH-1211 Geneva 23
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>
>
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>
-- Christo Kutrovsky Senior Database/System Administrator The Pythian Group -- http://www.freelists.org/webpage/oracle-l
Received on Mon Feb 13 2006 - 13:20:04 CST

Original text of this message

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