6 Replies Latest reply on Aug 20, 2010 1:19 PM by 618702

    ora_p000_process

    776020
      I has found some of the below process on standy database. Can anybody explain what this process do and what is the use in standy database.

      ora_p000_DatabaseName
      ora_p001_DatabaseName
      ora_p002_DatabaseName
      ora_p003_DatabaseName
      ora_p004_DatabaseName
      ora_p005_DatabaseName
      ora_p006_DatabaseName
        • 1. Re: ora_p000_process
          558383
          These processes are parallel execution processes in 11.2: http://download.oracle.com/docs/cd/E11882_01/server.112/e10820/bgprocesses.htm#REFRN104
          • 2. Re: ora_p000_process
            Fahd.Mirza
            Hi,
            These are parallel query slave processes and they start when you issue parallel statements. Parallel Query Coordinator process control these slaves.

            regards
            • 3. Re: ora_p000_process
              Jonathan Lewis
              Beginner wrote:
              I has found some of the below process on standy database. Can anybody explain what this process do and what is the use in standy database.

              ora_p000_DatabaseName
              ora_p001_DatabaseName
              ora_p002_DatabaseName
              ora_p003_DatabaseName
              ora_p004_DatabaseName
              ora_p005_DatabaseName
              ora_p006_DatabaseName
              A physical standby is basically a database running in recovery mode, and it's possible to enable parallel slaves for recovery. The feature is controlled by a parameter called recovery_parallelism. I guess this is set to at least seven in your standby parameter file.

              Regards
              Jonathan Lewis
              • 4. Re: ora_p000_process
                618702
                Dear Jonathan Lewis,

                http://download.oracle.com/docs/cd/E11882_01/backup.112/e10642/osrecvry.htm#BRADV221
                To override the default behavior of performing parallel recovery, use the RECOVER with the NOPARALLEL option, or RECOVER PARALLEL 0. 
                The RECOVERY_PARALLELISM initialization parameter controls instance or crash recovery only. 
                Media recovery is not affected by the value used for RECOVERY_PARALLELISM.
                Jonathan Lewis wrote:A physical standby is basically a database running in recovery mode
                What sort of recovery mode? Is it instance recovery or the media recovery? I think this is a media recovery because the MRP process is applying the archivelogs and applying an archivelog is a media recovery, not instance or the crash recovery operation.

                So what i think here is there is nothing to do with the RECOVERY_PARALLELISM parameter. Let me show you an illustration;
                SQL> show parameter recovery_parallelism
                
                NAME                                 TYPE        VALUE
                ------------------------------------ ----------- ------------------------------
                recovery_parallelism                 integer     4
                
                SQL> host ps -ef | grep ora_p | wc -l
                68
                Media Recovery;_

                http://download.oracle.com/docs/cd/E11882_01/server.112/e10897/backrest.htm#ADMQS09112

                Can you please correct me if you think i am wrong and i will be thankful.

                Regards.

                Ogan
                • 5. Re: ora_p000_process
                  Jonathan Lewis
                  Ogan Ozdogan wrote:

                  So what i think here is there is nothing to do with the RECOVERY_PARALLELISM parameter. Let me show you an illustration;
                  I think you're right, I was wrong - the parallelism on log apply isn't controlled by that parameter, it comes under the control of a different part of the code. From the 10.2 Dataguard Concepts and Administration manual ( http://download-uk.oracle.com/docs/cd/B19306_01/server.102/b14239/manage_ps.htm#BACHIBGG ) :

                  <blockquote>
                  +"+
                  +8.6 Tuning the Log Apply Rate for a Physical Standby Database+

                  +...+

                  +To implement parallel media recovery or Redo Apply, add the optional PARALLEL clause to the recovery command. Furthermore, set the database parameter PARALLEL_MAX_SERVERS to at least the degree of parallelism. The following examples show how to set recovery parallelism:+
                  {code}
                  RECOVER STANDBY DATABASE PARALLEL #CPUs * 2;
                  {code}
                  +"+
                  </blockquote>

                  Regards
                  Jonathan Lewis
                  • 6. Re: ora_p000_process
                    618702
                    Dear Jonathan Lewis,

                    Thank you very much for the explanation. I do appreciate.

                    Regards.

                    Ogan