Re: low buffer_hit_rate !!!!!

Angelica Rivas wrote:
>
> Hello to everybody!
>
> I have increased 300% the db_block_buffer parameter in the initSID.ora
> file but the buffer_hit_rate is still too low, I have made biger 3
> times (1500 each time) and restart the database, but it never has
> moved from the low number.
>
> My statistics says between 70 to 80 percent daily...
>
> What can I do to increase this ratio? Is There another hide parameter
> involved in this ratio?
>
> Thanks in advance, I will be so grateful...
> Regards...
>
> Angelica Rivas

Hi Angelica,
is is possible that there is program(s) which are making full table scans frequently? In such case the buffer hit ratio may be low and increading the cache woun't help.
Check to see statistic 'Table scans (long tables)' if it is increasing. If you have OEM you can quite simply identify those sessions.

Hope this helps.

-- 

Timo Haatainen
Carelcomp Forest Oy