Re: locks in CREATE TRIGGER, ADD FK

Neil Conway wrote:
> AndrewSN pointed out on IRC that ALTER TABLE ... ADD FOREIGN KEY and 
> CREATE TRIGGER both acquire AccessExclusiveLocks on the table they are 
> adding triggers to (the PK table, in the case of ALTER TABLE). Is this 
> necessary? I don't see why we can't allow SELECT queries on the table to 
> proceed while the trigger is being added.

Sorry, I forgot to mention: I think RowExclusiveLock or ExclusiveLock 
would be sufficient instead.

-Neil