Subject: Re: [COMMITTERS] pgsql: Fix LOCK TABLE to eliminate the race
	condition that could make it
From: Simon Riggs <simon@2ndQuadrant.com>
To: Tom Lane <tgl@postgresql.org>
Cc: pgsql-hackers@postgresql.org
In-Reply-To: <20090512164332.BFC1575407D@cvs.postgresql.org>
References: <20090512164332.BFC1575407D@cvs.postgresql.org>
Content-Type: text/plain
Date: Tue, 12 May 2009 21:50:38 +0100
Message-Id: <1242161438.3843.334.camel@ebony.2ndQuadrant>
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On Tue, 2009-05-12 at 16:43 +0000, Tom Lane wrote:

> Fix LOCK TABLE to eliminate the race condition that could make it give weird
> errors when tables are concurrently dropped.  To do this we must take lock
> on each relation before we check its privileges.  The old code was trying
> to do that the other way around, which is a bit pointless when there are lots
> of other commands that lock relations before checking privileges.  I did keep
> it checking each relation's privilege before locking the next relation, which
> is a detail that ALTER TABLE isn't too picky about.

If we're going to require cascaded permissions like this, would it make
sense to make GRANT cascade down the inheritance tree also? 

-- 
 Simon Riggs           www.2ndQuadrant.com
 PostgreSQL Training, Services and Support