Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Usenet -> c.d.o.server -> Re: Size of oracle background processes

Re: Size of oracle background processes

From: Thomas Kyte <tkyte_at_us.oracle.com>
Date: Thu, 30 Sep 1999 08:49:08 -0400
Message-ID: <QFrzNzFXSsFLl3=jJ=AAB82LmEg8@4ax.com>


A copy of this was sent to Anil Kamath <akk_16_at_yahoo.com> (if that email address didn't require changing) On Wed, 29 Sep 1999 17:35:18 GMT, you wrote:

>
>
>Its not the size of the SGA itself..I know the SGA is shared by
>all the Oracle background processes. The problem is that
>when I do a "top" on the solaris box each of the background SQL
>processes have a resident size of approximately the same size of the
>SGA..This will create too much swapping on the
>box Why should the size of these background processes be so
>huge. What is the connection between the resident size of the background
>processes and the SGA, Shouldn't they be independent of each other.
>

No -- the top command reports the SGA as well. They are not independent of eachother.

for example, top shows:

  PID USERNAME THR PRI NICE SIZE RES STATE TIME CPU COMMAND 13412 tkyte 1 -15 0 126M 117M sleep 0:00 0.00% oracle

but -- pmap shows:

# /usr/proc/bin/pmap -x 13412
13412: oracleoracle8 (DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))

Address   Kbytes Resident Shared Private Permissions       Mapped File
00010000   16000   10912   10016     896 read/exec         oracle
00FBE000     152     152      88      64 read/write/exec   oracle
00FE4000     424     312       -     312 read/write/exec    [ heap ]
80000000  109552  109552       -  109552 read/write/exec/shared  [shmid=0x66]
EF590000      16      16      16       - read/exec         libmp.so.2
EF5A2000       8       8       8       - read/write/exec   libmp.so.2
EF5B0000      88      80      80       - read/exec         libm.so.1
EF5D4000       8       8       8       - read/write/exec   libm.so.1
EF5E0000      24      16      16       - read/exec         libaio.so.1
EF5F4000       8       8       8       - read/write/exec   libaio.so.1
EF5F6000       8       -       -       - read/write/exec    [ anon ]
EF600000     592     560     560       - read/exec         libc.so.1
EF6A2000      32      32       8      24 read/write/exec   libc.so.1
EF6AA000       8       8       -       8 read/write/exec    [ anon ]
EF6C0000      16      16      16       - read/exec         libc_psr.so.1
EF6E0000      32      32      32       - read/exec         libsocket.so.1
EF6F6000       8       8       8       - read/write/exec   libsocket.so.1
EF6F8000       8       -       -       - read/write/exec    [ anon ]
EF700000     448     336     336       - read/exec         libnsl.so.1
EF77E000      40      40       8      32 read/write/exec   libnsl.so.1
EF788000      24      24       -      24 read/write/exec    [ anon ]
EF7A0000       8       8       8       - read/exec         libdl.so.1
EF7B0000       8       8       -       8 read/write/exec    [ anon ]
EF7C0000     120     120     120       - read/exec         ld.so.1
EF7EC000       8       8       8       - read/write/exec   ld.so.1
EFFF6000      40      40       -      40 read/write/exec    [ stack ]
-------- ------ ------ ------ ------ total Kb 127680 122304 11344 110960

So, taking away the SGA size of 109552, we can sort of find the 'real' size...

If the disks aren't spinning -- it ain't swapping.

>-anil
>
>In article <7ss63n$q07$1_at_birch.prod.itd.earthlink.net>,
> "Winnie Liu" <winnie_liu_at_infonet.com> wrote:
>> I'm sorry if I got your message wrong. But what is the problem for the
>700MB
>> SGA database to have a combined shared memory usage size of
>approximately
>> 700MB (which will be shared by all the background oracle processes).
>If your
>> box is running too slow. Maybe there is too much swapping going on.
>Increase
>> the swap space or simply decrease the SGA size.
>>
>> Winnie Liu
>> DBA
>> Infonet Services Corporation
>> mailto:winnie_liu_at_infonet.com
>>
>> Anil Kamath wrote in message <7srili$vks$1_at_nnrp1.deja.com>...
>> >
>> >
>> >My SGA for Oracle 8.0.5 is configured to utilize 700 MB of memory.
>> >What I see is that my background processes (dbw,reco,chpt...etc..)
>> >show a resident memory size of approximately 700MB. Whats wrong with
>> >this picture. This make my Solaris 2.6 box slow. Is this normal.
>> >If so,,then what is the solution..
>> >
>> >-anil
>> >
>> >
>> >--
>> >Anil Kamath
>> >SmartOnline Inc. (www.smartonline.com)
>> >
>> >
>> >Sent via Deja.com http://www.deja.com/
>> >Before you buy.
>>
>>

--
See http://osi.oracle.com/~tkyte/ for my columns 'Digging-in to Oracle8i'... Current article is "Part I of V, Autonomous Transactions" updated June 21'st  

Thomas Kyte                   tkyte_at_us.oracle.com
Oracle Service Industries     Reston, VA   USA

Opinions are mine and do not necessarily reflect those of Oracle Corporation Received on Thu Sep 30 1999 - 07:49:08 CDT

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US