Hi Chen, Looking at the docs it seems that some app is doing many connects/disconnects on the database. http://download.oracle.com/docs/cd/B28359_01/server.111/b28320/dynviews_3015.htm <http://download.oracle.com/docs/cd/B28359_01/server.111/b28320/dynviews_3015.htm> Do you have auditing turned on? You could query dba_audit_session and see how many logons are occurring, and the host and account used. I don't know what kind of application is using the database, but could the time correspond to a time that usage might be expected to increase? Jared Still Certifiable Oracle DBA and Part Time Perl Evangelist Oracle Blog: http://jkstill.blogspot.com Home Page: http://jaredstill.com On Wed, Oct 28, 2009 at 11:35 AM, Chen Shapira <cshapi@xxxxxxxxx> wrote: > Hi Oracle-L, > > I am wondering if anyone here ran into a situation where "connection > management call elapsed time" timed statistic accounted for 83% of > total DB time. We are also seeing long waits on "Library cache load > lock" with very high rates of timeout on this wait (91% timeout). > > This happens once every day or two, lasts two hours and then goes away > on its own. It doesn't seem to coincide with our regular peak activity > times or large reports, or backups or anything like this. > > If you have suggestions on where I should look or what could be a > possible cause for what I am seeing, I'd appreciate it a lot! > > Chen > -- > //www.freelists.org/webpage/oracle-l > > >