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Home -> Community -> Mailing Lists -> Oracle-L -> Re: 9i - Dynamic SGA - SGA_MAX_SIZE
Tanel,
I have done this.
ipcs -m would not give me the size of the memory acquired on my system so I used ipcs -a
I have also looked into the ps vax
Which gives more detail:
Currently this shows 199M reserved to the SGA
EM9I /oracle/app/oracle/product/9.2.0/dbs > ps avx|head -1
PID TTY S TIME SL PAGEIN VSZ RSS %CPU %MEM
COMMAND
OEM9I /oracle/app/oracle/product/9.2.0/dbs > ps avx|grep OEM9I
472016 ?? S 0:00.25 2 3 199M 6.2M 0.0 0.4
ora_dbw0_OEM9I
481099 ?? I 0:00.20 32 2 198M 5.2M 0.0 0.3
ora_d000_OEM9I
481163 ?? S 0:00.29 2 33 196M 3.8M 0.0 0.2
ora_pmon_OEM9I
481141 ?? S 0:00.18 2 8 196M 3.6M 0.0 0.2
ora_s000_OEM9I
480555 ?? S 0:01.49 19 125 195M 2.9M 0.0 0.2
ora_qmn0_OEM9I
481126 ?? I 0:00.66 184 41 195M 2.9M 0.0 0.2
ora_smon_OEM9I
481159 ?? S 0:00.25 3 34 199M 2.8M 0.0 0.2
ora_lgwr_OEM9I
480962 ?? S 0:00.60 1 5 195M 2.7M 0.0 0.2
ora_cjq0_OEM9I
481151 ?? I 0:00.20 748 2 195M 2.7M 0.0 0.2
ora_reco_OEM9I
481148 ?? S 0:00.43 2 2 195M 2.5M 0.0 0.2
ora_ckpt_OEM9I
481909 pts/22 S + 0:00.01 0 0 2.28M 232K 0.0 0.0 grep
OEM9I
I reduce the SGA_MAX_SIZE by 30M (keep all other parameters the same ) and
the memory acquired on the OS drops by 30M
481979 ?? S 0:00.25 2 0 167M 6.4M 0.0 0.4
ora_dbw0_OEM9I
481988 ?? S 0:00.19 19 0 166M 5.2M 0.0 0.3
ora_d000_OEM9I
482000 ?? S 0:00.19 1 0 164M 3.8M 0.0 0.2
ora_pmon_OEM9I
482040 ?? S 0:00.17 19 0 164M 3.6M 0.0 0.2
ora_s000_OEM9I
481976 ?? S 0:00.66 7 0 163M 2.9M 0.3 0.2
ora_smon_OEM9I
482004 ?? S 0:00.22 2 1 167M 2.8M 0.0 0.2
ora_lgwr_OEM9I
481946 ?? S 0:00.20 2 0 163M 2.7M 0.1 0.2
ora_cjq0_OEM9I
482024 ?? S 0:00.17 2 0 163M 2.5M 0.0 0.2
ora_ckpt_OEM9I
481998 ?? S 0:00.16 17 0 163M 2.4M 0.0 0.2
ora_reco_OEM9I
482030 ?? S 0:00.16 19 0 163M 2.4M 0.0 0.2
ora_qmn0_OEM9I
Oracle says this is what you would expect. It will grab the entire value of SGA_MAX_SIZE. This certainly seems to be correct I just think it is stupid. Why grab the memory from the os but never use it.
stephen.
stephen.hodgkinson_at_eaguk.com
"Tanel Poder"
<tanel.poder.00 To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
3_at_mail.ee> cc:
Sent by: Subject: Re: 9i - Dynamic SGA - SGA_MAX_SIZE
ml-errors_at_fatci
ty.com
01/08/03 12:19
Please respond
to ORACLE-L
Hi!
You should check mem usage from OS instead. Using ipcs -m for example.
Tanel.
>
>
> Hi,
>
> does anybody have any experience with setting the SGA_MAX_SIZE in 9i.
>
> I assumed the purpose of this parameter was that SGA would grow as
> requested to that limit.
>
> Example:
> You could configure your SGA to be 80M
> Set the SGA_MAX_SIZE to be 250M.
>
> I would have expected oracle to acquire 80M of memory from the UNIX
> machine.
>
> In fact using ipcs you can see that oracle will always acquire the value
> of SGA_MAX_SIZE.
>
> It acquires the extra space in the Variable Size of the SGA
>
>
>
>
>
> Sga_max_size=75m.
>
> Show sga:
> Total System Global Area 77041728 bytes
> Fixed Size 733248 bytes
> Variable Size 41943040 bytes
> Database Buffers 33554432 bytes
> Redo Buffers 811008 bytes
>
>
> sga_max_size=110M and keep everything else the same.
>
> show sga:
> Total System Global Area 114790680 bytes
> Fixed Size 733464 bytes
> Variable Size 79691776 bytes
> Database Buffers 33554432 bytes
> Redo Buffers 811008 bytes
> Database mounted.
> Database opened.
>
>
>
>
>
> I have raised a lengthy call on Metalink and the consultants are
convinced
> this is normal behaviour and what you would expect.
>
> Do people agree with the metalink consultants?
>
> Maybe my expectations were to high but I thought a dynamic sga would mean
I
> could change the amount of memory acquired by the UNIX box.
>
> All opinions welcome. I am on tru64 platform - 9.2.0.3.0
>
> Thanks, Stephen
>
>
>
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-- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Tanel Poder INET: tanel.poder.003_at_mail.ee Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). ****************************************************** This insert confirms that this email message and all associated attachments have been swept by TotalFinaElf using Network Associates VirusScan for the presence of computer viruses during the receipt of this message. ****************************************************** -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: INET: Stephen.HODGKINSON_at_eaguk.com Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).Received on Fri Aug 01 2003 - 06:59:23 CDT
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