Re: PostgreSQL not ACID compliant?

From: Christopher Browne <cbbrowne(at)acm(dot)org>
To: pgsql-hackers(at)postgresql(dot)org
Subject: Re: PostgreSQL not ACID compliant?
Date: 2003-09-20 01:13:09
Message-ID: m3brtgdzyy.fsf@wolfe.cbbrowne.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

In an attempt to throw the authorities off his trail, jd(at)commandprompt(dot)com ("Joshua D. Drake") transmitted:
> PostgreSQL does not support read uncommited and repeatable read
> isolation levels? If that is so... then PostgreSQL is NOT ACID
> compliant?

Are you certain that the source of the information was actually
credible?

If you need "repeatable read," then that means doing it in a
transaction scope with SET TRANSACTION ISOLATION LEVEL SERIALIZABLE.
On that side of things, the information source is presumably Downright
Wrong.

As for "read uncommitted," that's taboo to ACID.

After all, reading uncommitted data means depending on facts that
might well _evaporate_. You don't WANT "dirty reads."

In an Internet registry, for instance, that would mean that someone
might consult WHOIS and get address information for a half-baked
record that, due to a lack of funds on the part of a fly-by-night
registrar, never did get committed. That's WRONG.

Or that a payroll run might pick up phantom employees that someone
_considered_ hiring, but never finished the paperwork on. Again,
that's WRONG behaviour.

What kind of fool wants to get WRONG information that hasn't been
committed? (It's a given that they are a fool; the question is what
kind of fool...)
--
wm(X,Y):-write(X),write('@'),write(Y). wm('aa454','freenet.carleton.ca').
http://www.ntlug.org/~cbbrowne/lisp.html
Rules of the Evil Overlord #17. "When I employ people as advisors, I
will occasionally listen to their advice."
<http://www.eviloverlord.com/>

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Marc G. Fournier 2003-09-20 01:36:08 Re: NuSphere and PostgreSQL for windows
Previous Message Joshua D. Drake 2003-09-20 01:11:09 Re: PostgreSQL not ACID compliant?