locks detection and resolving them..

hi dbas:
how do i detect dead locks and how do i resolve it..
what are the types of locks that are important and need immediate action..
thanks

a lock is different from a deadlock.
to see deadlocks, just check your alert.log file, to resolve them it's quite hard since you need to look at your queries to know if you make a SELECT .. FOR UPDATE or a statement that could lead to a deadlock ...

for a lock, just look in v$lock, and join SID with v$session.sid, and v$session.paddr to v$process.addr(+), and you'll get everything about which object is locked, who locked it, and the lock mode (RS,RX,S,SRX,X)

OK.. If the dead locks are hard to find.. and if I can see them in alert.log file, then how can i simulate this and resolve it ..
Just want to get more hands on, before trying the same on situation.. thanks..

everything you ever wanted to know about deadlocks (and some things you didn't ) at:
http://metalink.oracle.com/metalink/...T&p_id=62365.1