Re: FOREIGN KEY and AccessExclusiveLock

O Achilleus Mantzios έγραψε στις Sep 29, 2004 :

>
> Hmm, (something went wrong with some mailer)

And again....
hope it gets right this time...
>
> Tom Lane wrote:
> > We're adding a trigger to it.
>

From the docs:

============================================================================
ACCESS EXCLUSIVE

Conflicts with locks of all modes (ACCESS SHARE, ROW SHARE, ROW
EXCLUSIVE, SHARE UPDATE EXCLUSIVE, SHARE, SHARE ROW EXCLUSIVE, EXCLUSIVE,
and ACCESS EXCLUSIVE). This mode guarantees that the holder is the only
transaction accessing the table in any way.


Acquired by the ALTER TABLE, DROP TABLE, REINDEX, CLUSTER, and VACUUM FULL
commands. This is also the default lock mode for LOCK TABLE statements
that do not specify a mode explicitly.


Tip: Only an ACCESS EXCLUSIVE lock blocks a SELECT (without FOR UPDATE)
statement.
============================================================================

Now, is the lock acquired for the CREATE TRIGGER an explicit
LOCK TABLE?
Because nothing is mentioned about triggers in
http://www.postgresql.org/docs/7.4/interactive/explicit-locking.html

--
-Achilleus