Optimal values in init.ora file

Hi!
I'm trying to optimize my init.ora file. We recently re-install this Oracle server(Redhat 9 + Oracle 8.1.7) and now it is too slow...before the re-install it was a fast work stallion! I lost my previous init.ora file :(
I know there's plenty of information on how to set the SGA on Oracle but all the articles I already read aren't very clear for me.

Here are my most important parameters in my init.ora file: open_cursors = 1000
max_enabled_roles = 120

db_files = 3000
db_file_multiblock_read_count = 32
db_block_buffers = 6400

#Variable size
shared_pool_size = 18000000
large_pool_size = 32000000
java_pool_size = 40000000

log_checkpoint_interval = 10000
log_checkpoint_timeout = 1800

processes = 250
log_buffer = 819200
db_block_size = 8192

This machine is a Pentium III with 256Mb of RAM, before the re-install it was
pretty fast, but now we're having performance problems. Is there a simple formula to set this values? depending on how much RAM & Processor I have?
thanks in advance for any suggestions
regards,
  -eduardo s.m. Received on Tue Nov 30 2004 - 17:50:41 CST