Re: parallel degree question

From: David Fitzjarrell <oratune_at_yahoo.com>
Date: Thu, 30 May 2013 12:06:31 -0700 (PDT)
Message-ID: <1369940791.38134.YahooMailNeo_at_web121604.mail.ne1.yahoo.com>



It looks like you're using Auto DOP and Parallel Statement Queuing; have you run an I/O calibration?
 

If the streams 'doesn 't always run' is it being put in the parallel statement queue?  Query V$SQL_MONITOR for a status of QUEUED to see which statements are still in the queue and look at the sql_exec_id to see where they are in that queue.
 

If that doesn't help possibly a bit more information on these streams might be in order. David Fitzjarrell  

 From: Johan Eriksson <valpis_at_gmail.com> To: Oracle Discussion List <oracle-l_at_freelists.org> Sent: Thursday, May 30, 2013 12:38 PM
Subject: parallel degree question   

(Oracle 11.2.0.3.5 AIX 6.1, 40 logical cpu's (20 cpu's SMT2)) Hi

I have the following parameters (which I think is the one needed to know)

parallel_degree_policy=auto
parallel_degree_limit$
parallel_servers_target_at_0
parallel_threads_per_cpu=2
parallel_max_servers€0

What I am running are 3 different batchstreams, and this normally works OK, I get an average of 48 processes. The problem is that the streams doesn't always run, and since it is very CPI intensive I would like a way to direct more processes to the streams that actually are running at the moment. Is there a good way I haven't thought about yet?

(the reason I am limiting the number of concurrent processes are that the application otherwise spawn away 500 processes due to hints in the sql and degree on objects and I get contention problem and can't use the memory effectively. changing the sql is of course not something I can do at this point. I have tried increase the number of processes, but as I do that, hello contention.)

I have a good balance at the moment (regarding cpu, memory, disk latency and so on), but the elapsed time is not what I would have expected and I need to run as much on the CPU at all time as possible, but still with limited number of processes

/johan

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Received on Thu May 30 2013 - 21:06:31 CEST

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