Re: AMD/64, SGA size

From: Michael Austin <maustin_at_firstdbasource.com>
Date: Fri, 04 Jun 2004 16:29:34 GMT
Message-ID: <Or1wc.4485$rN4.1719@newssvr22.news.prodigy.com>

Dmitry Melekhov wrote:
> Hello!
>
> I can't get SGA size more that 1.7Gb on Mandrake 9.2/2.6.3
> with 9.2.0.4:
>
> SQL> startup
> ORACLE instance started.
>
> Total System Global Area 1796705872 bytes
> Fixed Size 745040 bytes
> Variable Size 1761607680 bytes
> Database Buffers 33554432 bytes
> Redo Buffers 798720 bytes
> Database mounted.
> Database opened.
> SQL> alter system set shared_pool_size=1796705872;
> alter system set shared_pool_size=1796705872
> *
> ERROR at line 1:
> ORA-02097: parameter cannot be modified because specified value is invalid
> ORA-04033: Insufficient memory to grow pool
>
>
> shmmax value is very high
>
> any ideas?

How much physical memory do you have? Your SGA, as general rule of thumb, shouldn't be larger than 50% of Physical memory.. but there are cases where I have seen it at 62%. (40GB SGA on a 64GB 32way Alpha GS1280 running OpenVMS). Talk about flying....!!! Most of the reference tables got pinned in memory. The database was a somewhere in the 1-3TB range.

Michael Austin. Received on Fri Jun 04 2004 - 11:29:34 CDT