Oracle configuration parameters

[Dave Chamberlin]

In my init.ora file for Oracle 7.3.4, the previous DBA had changed db_block_lru_latches from 2 to 3, but I recently noticed that when Oracle runs, it only has 2. I then noticed that the cpu_count parameter is set to 1. I believe the lru latch count can only be 2x the cpu_count. Since I have 4 cpus, I think cpu_count should get changed - can I add a line in the init.ora file or do I have to change this another way? Thanks in advance.

[Anthony Goonetilleke]

The default value for this parameter is actually CPU_COUNT/2
The range of values should be from 1 to the CPU_COUNT

I once read that if the following query returns a higher value for misses than 3% you should increase it

SELECT child#, sleeps / gets ratio
FROM V$LATCH_CHILDREN
WHERE name= 'cache buffers lru chain';