When this is happening, in what mode is the lock being held? (I assume 'X'.) In what mode is the waiting lock? ('S' mode?) -Mark -- Mark J. Bobak Senior Database Administrator, System & Product Technologies ProQuest 789 E. Eisenhower, Parkway, P.O. Box 1346 Ann Arbor MI 48106-1346 +1.734.997.4059 or +1.800.521.0600 x 4059 mark.bobak@xxxxxxxxxxxxxxx <mailto:mark.bobak@xxxxxxxxxxxxxxx> www.proquest.com <http://www.proquest.com> www.csa.com <http://www.csa.com> ProQuest...Start here. From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Eagle Fan Sent: Thursday, November 29, 2007 3:05 AM To: oracle-l Subject: Re: what's "enq:TX - contention" any comments? Thanks On Nov 27, 2007 12:19 AM, Eagle Fan <eagle.f@xxxxxxxxx> wrote: hi: In 10g, oracle has four TX wait events: 1. enq:TX - row lock contention 2. enq:TX - index contention 3. enq:TX - ITL 4. enq:TX - contention I know the first three ones' meanings. But what does the last one "enq:TX - contention" mean? I know it means other TX enqueue types. But what's the *other* TX enqueues? Could anybody give me some examples? We have insert sql causes this TX contention. I searched metalink and oracle-l, but most doc/threads are discussing the first three ones. Thanks a lot. -- Eagle Fan Oracle DBA -- Eagle Fan Oracle DBA