Re: Oracle internal memory management

chafey_at_ecst.csuchico.edu (Chris Hafey) wrote:

> Hello,
> We have been getting 4031 (unable to allocate shared memory) errors. The
> only help for this error is "increase shared memory". We have tried this,
> but it doesn't solve the problem.
>
        

        Oracle version 7.2.2 has a bug that causes this error frequently. The LRU algorithm used to flush the shared pool sometimes doesn't work very well. If you are running this version try upgrade to 7.2.3, or, better, to 7.3.

        The 7.3 version can use small free segments of shared pool to attend free memory requirements.

        Also, try to execute the statement 'alter system flush shared pool' frequently. Use the cron scheduller to start a script that run this statements.

        You can also use the dbms_shared_pool package to pin large packages in shared pool to reduce fragmentation. Look for 'Oracle Unix Tunning', avaiable from Oracle.

        Thanks,

--
Luis Santos
Relacional Consultoria
Rio de Janeiro - Brazil