3 Replies Latest reply: Jul 14, 2006 8:48 AM by 447396 RSS

    gc current request wait event

    447396
      Hi,

      I am executing a delete on a particular table but it gets hang during delete execution. Wait event showing gc current request. and from v$lock I am getting TM lock. There is a materialized view log on that table.

      can any one suggest any way out.

      Regards,
      Koushik
        • 1. Re: gc current request wait event
          247514
          Try this query see if you find anything

          select s1.username || '@' || s1.machine
          || ' ( SID=' || s1.sid || ' ) is blocking '
          || s2.username || '@' || s2.machine || ' ( SID=' || s2.sid || ' ) ' AS blocking_status
          from v$lock l1, v$session s1, v$lock l2, v$session s2
          where s1.sid=l1.sid and s2.sid=l2.sid
          and l1.BLOCK=1 and l2.request > 0
          and l1.id1 = l2.id1
          and l2.id2 = l2.id2 ;
          • 2. Re: gc current request wait event
            447396
            Yesterday I killed the problematic session using "alter system kill session" command, but it was there with killed status. Today I have found that the session wasn't there so the query returns nothing.

            But can you please tell me why the wait event "gc current request" occurs. What is the significance of it and how to simulate it.

            Regards,
            Koushik
            • 3. Re: gc current request wait event
              447396
              I have executed the delete again.
              The following query initially give some blocking sessions.

              select s1.username || '@' || s1.machine
              || ' ( SID=' || s1.sid || ' ) is blocking '
              || s2.username || '@' || s2.machine || ' ( SID=' || s2.sid || ' ) ' AS blocking_status
              from v$lock l1, v$session s1, v$lock l2, v$session s2
              where s1.sid=l1.sid and s2.sid=l2.sid
              and l1.BLOCK=1 and l2.request > 0
              and l1.id1 = l2.id1
              and l2.id2 = l2.id2

              When I have closed those sessions the query returns nothing. But still the session is hanging due to "gc current request" wait event.

              Can you please suggest any way out.

              Regards,
              Koushik