Date: Mon, 24 Aug 2020 11:07:25 -0400
From: Bruce Momjian <bruce@momjian.us>
To: "David G. Johnston" <david.g.johnston@gmail.com>
Cc: =?utf-8?B?0J7Qu9C10LMg0KHQsNC80L7QudC70L7Qsg==?= <splarv@ya.ru>,
	Pg Docs <pgsql-docs@lists.postgresql.org>
Subject: Re: Create a Foreign Table for PostgreSQL CSV Logs
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On Mon, Aug 24, 2020 at 07:40:49AM -0700, David G. Johnston wrote:
> On Mon, Aug 24, 2020 at 6:17 AM Олег Самойлов <splarv@ya.ru> wrote:
> 
>     There must not be constraints at all. Constraints are needed to check
>     incoming data to the table. But here table is read-only for database!
> 
> 
> Please don't top-post.
> 
> 
> 
>     So all your constraints is totally useless.
>     > > could become:
>     > >
>     > > connection_from text check(connection_from ~ '^[^:]+:[0-9]+$) -- the
>     host and
>     > > port of the client, colon-separated
> 
> 
> I'll agree that the benefit for adding the constraints to a foreign table are
> less than for a normal table but it is still not zero.  Constraints are also a
> form of documentation.  And also can be used (at least non-null ones) during
> optimization.

I feel constraints are going to lose focus of what we are trying to
show.  Do the constraints actually do anything on a foreign table?  If
not, we would have to mention that here too, which might be fine.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EnterpriseDB                             https://enterprisedb.com

  The usefulness of a cup is in its emptiness, Bruce Lee