Actually we are already using ASSM. I think preallocating extents would be worth trying. I've received several helpful tips and directions to further research into. Thanks for all the help!! - Ravi On Sat, Apr 19, 2008 at 5:35 PM, Yong Huang <yong321@xxxxxxxxx> wrote: > Ravi, > > Ric's suggestion is great. Before doing that, you can also try > > alter table theBLOBtable modify lob (theBLOBcolumn) (allocate extent > (instance > 1)); > > Remember to include the "instance 1" so space is added below HWM, even if > you're not using RAC (ignore documentation's caution: only use it on RAC). > > Is your tablespace ASSM? If not, consider moving the LOB segment to an > ASSM > tablespace because it's more difficult to create HW contention on ASSM. > > Yong Huang > > > Subject: RE: enq HW - contention waits > > Date: Fri, 18 Apr 2008 17:41:06 -0500 > > From: "Ric Van Dyke" <ric.van.dyke@xxxxxxxxxx> > > > > When I've run into this in the past the culprit was a table with a LOB > > and the extent size was way too small. For them many times when they > > hit the HWM they were also allocating more extents. In their case the > > entire system was hanging when this happened because it was a very high > > use table. The table was rebuild with a 256M extent size and they > > didn't have the problem. > > > > Find table (or other type of segment) that is extending frequently and > > that might be the issue. You're still going to hit the HWM every now > > and then, but hopefully you won't be extending the segment at the same > > time. > > > > ----------------------- > > Ric Van Dyke > > Hotsos Enterprises > > > > > > > > > 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 -- > > > > > > ... > > > > > > TIA, > > > - Ravi Gaur > > > > > ____________________________________________________________________________________ > Be a better friend, newshound, and > know-it-all with Yahoo! Mobile. Try it now. > http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ > -- > //www.freelists.org/webpage/oracle-l > > >