job_queue_processes parameter

We are on 8.1.5

The doc. says that this parameter is for:
JOB_QUEUE_PROCESSES specifies the number of SNPn background processes per
instance...

So, if we have 8 jobs (that I can see in dba_jobs) and our job_queue_processes = 3; what does this mean ?

JOB_QUEUE_PROCESSES is OS process
Jobs is scheduled jobs

so what is the relationship between the two, if any; is there a limit (parameter) to the number of oracle jobs that I can schedule?

relation is if you dont have snpX processes you cant run scheduled jobs because those processes are the one who checks for jobs

Job queue processes process requests created by DBMS_JOB, and those requests are the scheduled JOBs

so is it good to have many job_queue_processes set or not?
one of my database server set job_queue_processes=0 and the other server is set to 14...

I set it to 4 because I have like 12 jobs only and they run in different hours

So what is a good job_queue_process number for lets say 15 jobs ? Is there a rule-of-thumb ?

Lets say job_queue_process =1, and there are 50 jobs, will some of them be delayed since there is only one SNP background process...have you seen any doc. that addresses this topic.

Nop, I just use common sense, I schedule the jobs in different hours at most I have 2 jobs running concurrently so 4 is enough for my 12 jobs :D

Thank you, I appreciate the quick responses.

I really have to understand better on init.ora files...any good sources or book that I can study..I have the Oracle Database Administration book from O'Reilly, but the explanation is too vague....any other good init.ora parameter file books or info

Just an update: :)

For 9i, the SNP processes have been renamed as "J" processes and their max value has also been increased from 36 (till 8.1.7) to 1000. Thus, the JOB_QUEUE_PROCESSES parameter from 9i onwards will spawn the J000-J999 processes instead of the present SNP0-Z processes.

-amar

And to add to that: parameter JOB_QUEUE_INTERVAL has been removed from 9i, it is not supported any more. The master job queue process will wake up any 5 seconds and scan if there is any job to be processed in the waiting queue, and if needed it will spawn a slave job queue proces to handle that job. The whole scheduling mechanism has been totaly reengineered in 9i.