locks detection and resolving them..

[st2000]

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

[pipo]

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)

[st2000]

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..

[marist89]

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