Date: Thu, 24 Oct 2019 10:31:44 -0400
From: Bruce Momjian <bruce@momjian.us>
To: Tuomas Leikola <tuomas.leikola@gmail.com>
Cc: pgsql-docs@lists.postgresql.org
Subject: Re: uniqueness and null could benefit from a hint for dba
Message-ID: <20191024143144.GE8650@momjian.us>
References: <156760275564.1127.12321702656456074572@wrigleys.postgresql.org>
 <20190927163747.GE31412@momjian.us>
 <CALhc4GAq4H9DSeC7tU6Nkr34zykiA4g8WQ+suWmXSXTDApgHEA@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: 
 <CALhc4GAq4H9DSeC7tU6Nkr34zykiA4g8WQ+suWmXSXTDApgHEA@mail.gmail.com>
User-Agent: Mutt/1.10.1 (2018-07-13)
Precedence: bulk

On Wed, Oct 23, 2019 at 02:35:02PM +0300, Tuomas Leikola wrote:
> That is a nice design. You can create a regular unique index where columns(s)s
> are not null and then filtered index(es) for the cases where some of the unique
> columns are null.
> 
> However my point, specifically, was that if the document in question would have
> offered alternative solutions, I personally would have been saved from some
> frustration and an exercise in bad index design (I had 5 nullables that need
> uniqueness for the null as well). Maybe it would help someone else.

Uh, I am wondering if it is just too details for our docs.  Can you
think of some text and its location?

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +