Re: Oracle 8i and ESMA

Increasing db_block_buffers should be based on measuring the hitrate by running ultbstat and utlestat.
Bumping up db_block_buffers indiscriminatly is not going help, it will only increase paging activities, making your loose any gain. As a general guideline the total SGA should not be bigger than about one third of physical memory, so in your case 2.3 G. More than 256k db_block_buffers (regardless of block_size and you don't specify that one) is clearly outrageous, and it is not going to help you a damn, as for the last .1 percent hitrate increase you need extraordinary amounts of memories.
I recommend measuring the hitrate first before you proceed. If it is above 95 percent, don't do anything to increase it, between 90 and 95 percent it is questionable to anything.

Hth,

Sybrand Bakker, Oracle DBA

<pvinnakota_at_my-deja.com> wrote in message news:8tcld2$5o6$1_at_nnrp1.deja.com...
> Hi,
> We installed Oracle 8i (8.1.6) on an NT server with 8GB RAM. Now we are
> trying to increase the SGA size beyond 4GB using the guidelines in the
> whitepaper on this subject. I followed the guidelines and made the
> requisite modifications to the init.ora etc.
>
> In the process, we could ramp the SGA size up to 2.7GB by gradually
> increasing the DB_BLOCK_BUFFERS. There was a gradual increase in the
> SGA size from 623MB to 2.7GB. Once the the DB_BLOCK_BUFFERS number
> crosses certain limit(256k), the size of the SGA is reverting to a very
> small size (157MB).
>
> Has anyone tried this and succeeded? Please help with your insights.
>
> Thanks,
>
> Prasad V.,
>
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
Received on Fri Oct 27 2000 - 23:49:14 CDT