Hi,

I notice on the SET CONSTRAINTS doc page, it says SET CONSTRAINTS
<constraint> ...

But it doesn't at all make it clear what <constraint> is, since cosntraint
names are per-relation I thought?

Chris


Wed, 13 Aug 2003 13:48:21 +0800
"Christopher Kings-Lynne" <chriskl@familyhealth.com.au>
set constraints docs page
"Christopher Kings-Lynne" <chriskl@familyhealth.com.au> writes:
> I notice on the SET CONSTRAINTS doc page, it says SET CONSTRAINTS
> <constraint> ...
> But it doesn't at all make it clear what <constraint> is, since cosntraint
> names are per-relation I thought?

Looking at the code, it will set the mode for *all* FKs with the same
constraint name, regardless of which relation they are on.

Feel free to send a doc patch...

			regards, tom lane

Wed, 13 Aug 2003 10:05:13 -0400
Tom Lane <tgl@sss.pgh.pa.us>
Re: set constraints docs page 

On Wed, 13 Aug 2003, Christopher Kings-Lynne wrote:

> Hi,
>
> I notice on the SET CONSTRAINTS doc page, it says SET CONSTRAINTS
> <constraint> ...
>
> But it doesn't at all make it clear what <constraint> is, since cosntraint
> names are per-relation I thought?

It's a constraint name.  IIRC, it happens to affect all such named
constraints currently. We should probably allow <tablename>.<constraint>
(and <schema>.<tablename>.<constraint>) as well. Too late for 7.4, but
this can happen for 7.5 if there aren't any objections.


Wed, 13 Aug 2003 08:19:58 -0700 (PDT)
Stephan Szabo <sszabo@megazone.bigpanda.com>
Re: set constraints docs page
Stephan Szabo writes:

> It's a constraint name.  IIRC, it happens to affect all such named
> constraints currently. We should probably allow <tablename>.<constraint>
> (and <schema>.<tablename>.<constraint>) as well. Too late for 7.4, but
> this can happen for 7.5 if there aren't any objections.

I object.

-- 
Peter Eisentraut   peter_e@gmx.net

Tue, 19 Aug 2003 09:32:52 +0200 (CEST)
Peter Eisentraut <peter_e@gmx.net>
Re: set constraints docs page
> > It's a constraint name.  IIRC, it happens to affect all such named
> > constraints currently. We should probably allow <tablename>.<constraint>
> > (and <schema>.<tablename>.<constraint>) as well. Too late for 7.4, but
> > this can happen for 7.5 if there aren't any objections.
>
> I object.

Thanks for the helpful objection.  To what do you object specifically and
why?

Chris


Tue, 19 Aug 2003 15:44:42 +0800
"Christopher Kings-Lynne" <chriskl@familyhealth.com.au>
Re: set constraints docs page
Christopher Kings-Lynne writes:

> > > It's a constraint name.  IIRC, it happens to affect all such named
> > > constraints currently. We should probably allow <tablename>.<constraint>
> > > (and <schema>.<tablename>.<constraint>) as well. Too late for 7.4, but
> > > this can happen for 7.5 if there aren't any objections.
> >
> > I object.
>
> Thanks for the helpful objection.  To what do you object specifically and
> why?

I object to creating gratuitous incompatibilities with the SQL standard,
which will obstruct legitimate features down the road.  The SQL standard
says it is <schema>.<constraint>.

-- 
Peter Eisentraut   peter_e@gmx.net

Tue, 19 Aug 2003 09:51:51 +0200 (CEST)
Peter Eisentraut <peter_e@gmx.net>
Re: set constraints docs page

----- Original Message ----- 
From: "Peter Eisentraut" <peter_e@gmx.net>
To: "Christopher Kings-Lynne" <chriskl@familyhealth.com.au>
Cc: "Stephan Szabo" <sszabo@megazone.bigpanda.com>; "Hackers"
<pgsql-hackers@postgresql.org>
Sent: Tuesday, August 19, 2003 3:51 AM
Subject: Re: [HACKERS] set constraints docs page


> Christopher Kings-Lynne writes:
>
> > > > It's a constraint name.  IIRC, it happens to affect all such named
> > > > constraints currently. We should probably allow
<tablename>.<constraint>
> > > > (and <schema>.<tablename>.<constraint>) as well. Too late for 7.4,
but
> > > > this can happen for 7.5 if there aren't any objections.
> > >
> > > I object.
> >
> > Thanks for the helpful objection.  To what do you object specifically
and
> > why?
>
> I object to creating gratuitous incompatibilities with the SQL standard,
> which will obstruct legitimate features down the road.  The SQL standard
> says it is <schema>.<constraint>.
>

Is there a case for enforcing uniqueness on constraint names, then?

andrew


Tue, 19 Aug 2003 08:08:20 -0400
"Andrew Dunstan" <andrew@dunslane.net>
Re: set constraints docs page
"Andrew Dunstan" <andrew@dunslane.net> writes:
>> I object to creating gratuitous incompatibilities with the SQL standard,
>> which will obstruct legitimate features down the road.  The SQL standard
>> says it is <schema>.<constraint>.

> Is there a case for enforcing uniqueness on constraint names, then?

Other than "SQL92 says so"?  Very little.  This seems to me to be a
design error in the spec.  Per-table constraint names are easier to
work with --- if they're global across a schema then you have a serious
problem avoiding collisions.

The spec does have a notion of "assertions", which are constraints not
tied to any specific table; for those I suppose you need a
schema-wide namespace.  I do not foresee us supporting such things
anytime soon though.

			regards, tom lane

Tue, 19 Aug 2003 09:46:55 -0400
Tom Lane <tgl@sss.pgh.pa.us>
Re: set constraints docs page 

On Tue, 19 Aug 2003, Peter Eisentraut wrote:

> Christopher Kings-Lynne writes:
>
> > > > It's a constraint name.  IIRC, it happens to affect all such named
> > > > constraints currently. We should probably allow <tablename>.<constraint>
> > > > (and <schema>.<tablename>.<constraint>) as well. Too late for 7.4, but
> > > > this can happen for 7.5 if there aren't any objections.
> > >
> > > I object.
> >
> > Thanks for the helpful objection.  To what do you object specifically and
> > why?
>
> I object to creating gratuitous incompatibilities with the SQL standard,
> which will obstruct legitimate features down the road.  The SQL standard
> says it is <schema>.<constraint>.

We *already* have the incompatibility with the SQL standard because of the
fact we allow non-unique constraint names in the same schema;
<schema>.<constraint> does not uniquely identify a constraint in
PostgreSQL currently.

Tom objected to following the spec on this regard back when the issue was
brought up for adding checks on the constraint names on the grounds that
table based constraint names were more natural.


Tue, 19 Aug 2003 08:37:41 -0700 (PDT)
Stephan Szabo <sszabo@megazone.bigpanda.com>
Re: set constraints docs page