Re: CONSTRAINT does not show when applying a EXCLUDE constraint

From: InterRob <rob(dot)marjot(at)gmail(dot)com>
To: pgsql-general <pgsql-general(at)postgresql(dot)org>
Subject: Re: CONSTRAINT does not show when applying a EXCLUDE constraint
Date: 2010-12-27 20:50:57
Message-ID: AANLkTimb3LVd80KtnLgsDa3u5EF7PZ9X6RHOJCur3L80@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

Sorry: that is because the major part of my E-mail got chopped off...
Herewith I am resending it:

-----------------------------------------------

Dear list,

To rule out any double combination of two identifiers, in any order, I
applied the following constraint to a table:

CREATE TABLE test(
object_id INTEGER,
subject_id INTEGER,
CONSTRAINT "EXCL_double_combi" EXCLUDE USING btree (imm_LEAST(subject_id,
object_id) WITH =, imm_GREATEST(subject_id, object_id) WITH =)
);

The imm_xxxxx functions are IMMUTABLE wrappers around LEAST() and GREATEST()
respectively, in order to get the index to work...

pgsql Command "\d test" produces the following:
Table "public.test"
Column | Type | Modifiers
------------+---------+-----------
object_id | integer |
subject_id | integer |
Indexes:
"EXCL_double_combi" EXCLUDE USING btree (imm_least(subject_id,
object_id) WITH =, imm_greatest(subject_id, object_id) WITH =)

As I read it, an indexed in indeed being maintained, however it is not
regarded a CONSTRAINT... Yet, the set-up works as like a charm :)) This
online example shows a different summary:
http://www.depesz.com/index.php/2010/01/03/waiting-for-8-5-exclusion-constraints/
Would this be an earlier / older version of PostgreSQL? I'm running 9.0.2,
on Windows 7

By the way: has any one experience using EXCLUDE constraint inside
Enterprise Architect? Since this is a pretty new database feature, it seems
not yet supported by EA?

Looking forward to any of you sharing your experiences,
kind regards,

Rob
-----------------------------------------------

2010/12/27 Richard Broersma <richard(dot)broersma(at)gmail(dot)com>

> On Mon, Dec 27, 2010 at 8:31 AM, Rob Marjot <rob(at)marjot-multisoft(dot)com>
> wrote:
> > Dear list,
> > To rule out any double combination of two identifiers, in any order, I
> > applied the following constraint to a table:
> > CREATE TABLE test(object_id INTEGER, subject_id INTEGER, CONSTRAINT
>
> I don't see the definition of your constraint.
>
> --
> Regards,
> Richard Broersma Jr.
>
>

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Richard Broersma 2010-12-27 21:02:03 Re: CONSTRAINT does not show when applying a EXCLUDE constraint
Previous Message Richard Broersma 2010-12-27 20:37:55 Re: CONSTRAINT does not show when applying a EXCLUDE constraint