enq HW - contention waits

From: Ravi Gaur <ravigaur1_at_gmail.com>
Date: Fri, 18 Apr 2008 15:33:58 -0500
Message-ID: <289232290804181333x6735d546pd40e2af7c3fddc14@mail.gmail.com>


We have a production database running on RAC (4-node) ( 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

Received on Fri Apr 18 2008 - 15:33:58 CDT

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