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Home -> Community -> Mailing Lists -> Oracle-L -> FW: Truncate table - interaction with a long running query
Mea culpa. My earlier post about queries and DDL confused parse locks with row locks. A query holds no locks at all. I really have to resist the impulse to answer questions quickly without confirming the accuracy of what I'm about to say.
Parse locks, from the Concepts manual:
A SQL statement (or PL/SQL program unit) in the shared pool holds a parse lock for each schema object it references. Parse locks are acquired so that the associated shared SQL area can be invalidated if a referenced object is altered or dropped. A parse lock does not disallow any DDL operation and can be broken to allow conflicting DDL operations, hence the name breakable parse lock.
A parse lock is acquired during the parse phase of SQL statement execution and held as long as the shared SQL area for that statement remains in the shared pool.
Paul Baumgartel
CREDIT SUISSE
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-- http://www.freelists.org/webpage/oracle-lReceived on Wed Aug 15 2007 - 15:44:53 CDT
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