DB_BLOCK_BUFFER

[sunkutup]

What is best method to increase the db_block_buffers and db_block_lru_latches without encountering error.

This area has shown to affect the database perfomance.

[julian]

Originally posted by sunkutup
What is best method to increase the db_block_buffers and db_block_lru_latches without encountering error.

This area has shown to affect the database perfomance.

Set db_block_lru_latches to 6 times the CPUs. If you have 1 CPU, then setting db_block_lru_latches to 6 will not help much.

How much memory do you have? What do you have now for db_block_buffers?

[hrishy]

Hi

How many cpu 's do you have on your machine.set the db_block_lru_latches to approximately twice the number of cpus if your instance is hevaily loaded.say for example if u have 10 cpus i suggest that you first start out with something like 5 then check for latch contenation with V$LATCH,V$SESSION_EVENT
Note however if you have a single cpu machine you wont greatly benifit by setting this paarmeter.

hope this helps

regards
Hrishy

[sunkutup]

We are running oracle on active-pasive clustering on NT 4.0. The memory for the each nodes is 1.2 GB. Currently we havedb_block_buffers = 1550
db_block_lru_latches = 31.

[julian]

Try changing them to:

db_block_buffers = 40000
db_block_lru_latches = 12

Do you use keep or recycle pool? Like:

buffer_pool_keep = (buffers:5000, lru_latches:2)
buffer_pool_recycle = (buffers: 10000, lru_latches:2)

I would recommend setting a recycle pool in init.ora to something only if you know and understand why you are doing that!