enq HW - contention waits
Date: Fri, 18 Apr 2008 15:33:58 -0500
We have a production database running on RAC (4-node) (10.2.0.3 on Solaris 10) and I'm noticing a lot of waits on "enq: HW - contention". Doing a bit of researching tells me that it is related to HWM extensions (concurrent inserts). We have no control on the application so I wonder what could be done from the database end to tune this up (if anything). Here's what I see from the AWR during the time it showed up --
Top 5 Timed Events
EventWaitsTime(s)Avg Wait(ms)% Total Call TimeWait Class CPU time 7,148 43.5 enq: HW - contention 67,034 5,263 79 32.0Configuration SQL*Net break/reset to client 61,006 1,504 25 9.2Application db file sequential read 152,431 88565.4User
I/O gc cr block busy 34,315 490 14 3.0Cluster Any help is deeply appreciated!!
- Ravi Gaur