Re: pgsql: Foreign keys on partitioned tables

Robert Haas wrote:
> On Wed, Apr 4, 2018 at 1:03 PM, Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
> > Foreign keys on partitioned tables
> >
> > Author: Álvaro Herrera
> > Discussion: https://postgr.es/m/20171231194359.cvojcour423ulha4@alvherre.pgsql
> > Reviewed-by: Peter Eisentraut
> 
> The commit message here was so brief that I had to read the
> documentation to figure out exactly what this feature was.

I wrote three draft commit messages, and they all seemed to be saying
something so obvious (just repeating the commit title) that I decided
not to repeat myself.  Evidently that was a mistake.

> In so doing, I ran across this, which seems to need some cleanup:
> 
> +      Also, while it's possible to define <literal>PRIMARY KEY</literal>
> +      constraints on partitioned tables, it is not supported to create foreign
> +      keys cannot that reference them.  This restriction will be lifted in a
> +      future release.
> 
> Generally, I think we're better off not committing to doing things in
> a future release because we never really know what will happen in the
> future,

True.  I removed that sentence, leaving a "yet" that hints to the future
without making (I hope) too much of a promise.

> but the biggest problem here is that "it is not supported to
> create foreign keys cannot that reference them" doesn't make any
> sense.  I think you mean something like "creating foreign keys that
> reference a partitioned table is not supported".

Yeah, I edited this a few times and evidently one word from some
previous iteration ("cannot") escaped deletion.  I liked your wording so
I used it.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
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