Re: ALTER TABLE lock strength reduction patch is unsafe

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>
To: Simon Riggs <simon@2ndquadrant.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2011-06-24T21:43:47Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Add bytea_agg, parallel to string_agg.

  2. Fix ALTER TABLE ONLY .. DROP CONSTRAINT.

On Fri, Jun 24, 2011 at 5:28 PM, Simon Riggs <simon@2ndquadrant.com> wrote:
> I've explained all of the above points to you already and you're wrong.

We're going to have to agree to disagree on that point.

> Do you advocate that all ALTER TABLE operations use
> AccessExclusiveLock, or just the operations I added? If you see
> problems here, then you must also be willing to increase the lock
> strength of things such as INHERITS, and back patch them to where the
> same problems exist. You'll wriggle out of that, I'm sure. There are
> regrettably, many bugs here and they can't be fixed in the simple
> manner you propose.

I think there is quite a lot of difference between realizing that we
can't fix every problem, and deciding to put out a release that adds a
whole lot more of them that we have no plans to fix.

> It's not me you block Robert, I'm not actually a user and I will sleep
> well whatever happens, happy that I tried to resolve this. Users watch
> and remember.

If you are proposing that I should worry about a posse of angry
PostgreSQL users hunting me down (or abandoning the product) because I
agreed with Tom Lane on the necessity of reverting one of your
patches, then I'm willing to take that chance.  For one thing, there's
a pretty good chance they'll go after Tom first.  For two things,
there's at least an outside chance I might be rescued by an
alternative posse who supports our tradition of putting out high
quality releases.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company