Re: Fw: 'shared pool'

It's because of the SGA_MAX_SIZE parameter, which is, of course, rounded so that the SGA can be aligned to the page boundary. On Wed, 2003-10-08 at 19:59, bulbultyagi_at_now-india.net.in wrote:
> Mladen ,is all this
> documented anywhere or is it all very common knowledge ? I can't believe
> that all you expert dbas would let Oracle take away tens of mbs of memory
> without
> telling you.
>
> ----- Original Message -----
> To: <ORACLE-L_at_fatcity.com>
> Sent: Thursday, October 09, 2003 04:11
>
>
> > Mladen , thanks for replying . Please tell me why does one get a
> difference
> > between the values returned from v$sgastat and the shared pool size set
> in
> > the parameter file ?
> > Please , explain this to me . Arup explained that the memory required to
> > manage the buffer
> > cache is also allocated from the shared pool. Is there any ratio or does
> > this mean that if I allocate x MB to my buffer cache, Oracle
> > allocates that x mb for the buffer cache , and an additional x mb or 32
> mb
> > for
> > managing the buffer cache and places it in the shared pool ?
> >
> >
> >
> > ----- Original Message -----
> > From: "Mladen Gogala" <mladen_at_wangtrading.com>
> > To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com>
> > Sent: Wednesday, October 08, 2003 03:49
> > Subject: Re: 'shared pool'
> >
> >
> > >
> > > Not so on my instance.
> > >
> > > SQL> select sum(bytes) from v$sgastat
> > > 2 where pool='shared pool';
> > >
> > > SUM(BYTES)
> > > ----------
> > > 251658240
> > >
> > > SQL> show parameter shared_pool
> > >
> > > NAME TYPE VALUE
> > > ------------------------------------ -----------
> > > ------------------------------
> > > shared_pool_reserved_size big integer 10905190
> > > shared_pool_size big integer 218103808
> > > SQL> select 251658240-218103808 from dual;
> > >
> > > 251658240-218103808
> > > -------------------
> > > 33554432
> > >
> > > SQL> show parameter db_cache_size
> > >
> > > NAME TYPE VALUE
> > > ------------------------------------ -----------
> > > ------------------------------
> > > db_cache_size big integer 419430400
> > > SQL>
> > >
> > > On Tue, 2003-10-07 at 17:54, bulbultyagi_at_now-india.net.in wrote:
> > > > List please try out the following :
> > > > 1. select sum(bytes) from v$sgastat where pool='shared pool';
> > > >
> > > > 2. find out the size of the shared pool you have specified in your
> > > > parameter files.
> > > >
> > > > 3. subtract the two values
> > > >
> > > > 4. When I do the same as above the difference is exactly equal to my
> > > > db_cache_size.
> > > >
> > > > So does this mean that if I allocate x MB to my buffer cache, Oracle
> > > > allocates that x mb for the buffer cache , and an additional x mb for
> > > > managing the buffer cache and places it in the shared pool ?
> > > >
> > > > Please explain this to me.
> > > >
> > > > --
> > > > Please see the official ORACLE-L FAQ: http://www.orafaq.net
> > > --
> > > Mladen Gogala
> > > Oracle DBA
> > >
> > >
> > >
> > >
> > > Note:
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> > > --
> > > Please see the official ORACLE-L FAQ: http://www.orafaq.net
> > > --
> > > Author: Mladen Gogala
> > > INET: mladen_at_wangtrading.com
> > >
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-- 
Mladen Gogala
Oracle DBA




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-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: Mladen Gogala
  INET: mladen_at_wangtrading.com

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