Re: DDL & long-running query

Mladen,

A parse lock is also called breakable parse lock. To me, the name "lock" here is a misnomer. It doesn't really lock anything; instead it passively serves as an alert mechanism to invalidate cursors in library cache when the definition of dependent objects is changed by a DDL. That is, instead of the DDL being stopped, the "lock" breaks itself and invalidates the library cache object.

I think Cursor Definition Locks in null mode in dba_lock_internal represent these parse locks. You can also find them in dba_kgllock where kgllktype = 'Lock' (but have to match its kgllkhdl with x$kglob.kglhdadr to find the cursor text). These locks are not in v$lock or dba_lock.

Yong Huang
yong321ATyahoo.com Received on Thu May 12 2005 - 15:54:52 CDT