Re: 2PC-induced lockup

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Heikki Linnakangas <heikki@enterprisedb.com>
Cc: Peter Eisentraut <peter_e@gmx.net>, pgsql-hackers@postgresql.org, Chris Browne <cbbrowne@acm.org>
Date: 2007-07-11T19:53:42Z
Lists: pgsql-hackers
Heikki Linnakangas <heikki@enterprisedb.com> writes:
> Peter Eisentraut wrote:
>> Heikki Linnakangas wrote:
>>> It's not? I agree with Tom here; this is just one of the numerous
>>> things you can do to screw up your database as a superuser. Why would
>>> you LOCK the pg_auth table, or any other system table for that
>>> matter, in the first place? Let alone in a distributed transaction.
>> 
>> Well, my test case arose from a real application scenario, not an 
>> attempt to destroy my database system.

> Why does the application LOCK pg_auth?

Even if there is a reason for a lock, surely it's not necessary to use
AccessExclusiveLock.  A lesser lock would synchronize whatever the heck
it's doing without locking out readers.

			regards, tom lane