Oracle Database Discussions

Hello,
I am working on Oracle 10.2.0.4 on AIX .
In awr reports we found 'row lock contention' as top wait events. As my knowledge There are two types of locks..

1. Deadlock - where oracle will automatically rollback the locking query and generate deadlock trace file.

2. A user session update some rows and not commit/rollback , so other sessions which need to lock same rows , were witing. So dba need to manully kill first
session which was holding lock.


We want to know , in which of above scenario in awr report we can see 'row lock contention' wait.

any idea ..