Re: Can I use more memory than I have?

I recall Thomas Kyte's book mentioning something about this. If I'm not mistaken, actual memory taken by the shared pool is slightly more than that set by shared_pool_size, which should make up for the difference you see. There are also some internal structures and things that are accounted under 'shared pool' in v$sgastat and are allocated extra to the shared_pool_size setting. Not sure if I am correct though.

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Vladimir Zakharychev (bob@dpsp-yes.com)                http://www.dpsp-yes.com
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"Knut Talman" <knut.talman_at_mytoys.de> wrote in message news:3D120C50.EDDC02D0_at_mytoys.de...


> When I issue the following:

> 

> select  sum(a.bytes)/(1024*1024) shared_pool_used,

>         max(b.value)/(1024*1024) shared_pool_size,

>        (max(b.value)/(1024*1024))-(sum(a.bytes)/(1024*1024)) shared_pool_avail,

>        (sum(a.bytes)/(max(b.value)))*100 shared_pool_pct

>   from v$sgastat a, v$parameter b

>  where a.pool  = 'shared pool'

>    and a.name != 'free memory'

>    and b.name  = 'shared_pool_size';

> 

> 

> I get

> 

> SHARED_POOL_USED SHARED_POOL_SIZE SHARED_POOL_AVAIL SHARED_POOL_PCT

> ---------------- ---------------- ----------------- ---------------

>            51.83            50.00             -1.83          103.67

> 

> And

> 

> select * from v$sgastat

> where name='free memory'

> and pool = 'shared pool';

> 

> shows

> 

> POOL        NAME                            BYTES

> ----------- -------------------------- ----------

> shared pool free memory                   2891628

> 

> So I have 50MB and I am using 103.67 percent of it. And there are still some

> free bytes left... Where is my mistake?

> 

> Regards,

> 

> Knut