Re: Constraint documentation

Lætitia Avrot <laetitia.avrot@gmail.com>

From: Lætitia Avrot <laetitia.avrot@gmail.com>
To: coelho@cri.ensmp.fr
Cc: pgsql-hackers@lists.postgresql.org
Date: 2018-06-25T14:02:06Z
Lists: pgsql-hackers
Thanks!
I'll correct the patch ASAP including your modifications.

Le sam. 23 juin 2018 à 19:15, Fabien COELHO <coelho@cri.ensmp.fr> a écrit :

>
> Hello lætitia,
>
> My 0.02 € to try to simplify the suggested documentation.
>
> > Check constraint were not
>
> are not
>
> > designed to enforce business rules across tables.
>
> > Avoid using check constraints with function accessing to other tables
>
> accessing other tables (no "to")
>
> > and prefer triggers instead (please refer to <xref linkend="triggers"/>
> > for more information about triggers).
>
> ... and use <xref linkend="triggers"/> instead.
>
> > PostgreSQL won't prevent you from doing so,
>
> Although PostgreSQL ... so,
>
> > but be aware you might encounter difficulties to restore dumps
> > (generated with pg_dump or pg_dumpall) if you do.
>
> beware that dumps generated by <application>pg_*<...> or <...> may be hard
> to restore because of such checks, as the underlying dependencies are not
> taken into account.
>
> --
> Fabien.



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Commits

  1. Clarify that cross-row constraints are unsupported