Re: CHECK NO INHERIT syntax

Alvaro Herrera <alvherre@commandprompt.com>

From: Alvaro Herrera <alvherre@commandprompt.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Peter Eisentraut <peter_e@gmx.net>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2012-07-21T04:20:57Z
Lists: pgsql-hackers

Attachments

Excerpts from Tom Lane's message of vie jul 20 16:12:05 -0400 2012:
> 
> Alvaro Herrera <alvherre@commandprompt.com> writes:
> > True.  I have added an error check at creation time.  Please suggest
> > improved wording for the message:
> 
> > alvherre=# create domain positiveint2 as int check (value > 0) no inherit;
> > ERROR:  CHECK constraints for domains cannot be NO INHERIT
> 
> I think "CHECK constraints for domains cannot be marked NO INHERIT"
> would be fine.

Thanks.

> >  ConstraintElem:
> > -            CHECK opt_no_inherit '(' a_expr ')' ConstraintAttributeSpec
> > +            CHECK '(' a_expr ')' opt_no_inherit ConstraintAttributeSpec
> 
> This doesn't seem to me to meet the principle of least surprise.  Surely
> NO INHERIT ought to be folded into ConstraintAttributeSpec so that it
> acts like other constraint decorations, ie order isn't significant.

Oh, true; that's a bit more involved.  I verified it works correctly to
have a constraint marked NOT VALID NO INHERIT or the other way around.
I haven't checked whether the changes to ConstraintAttributeSpec have
side effects -- I think it's OK but I might be missing something.

Here's a (hopefully) complete patch.

-- 
Álvaro Herrera <alvherre@commandprompt.com>
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