public inbox for [email protected]  
help / color / mirror / Atom feed
From: Dominique Devienne <[email protected]>
To: Bruno Wolff III <[email protected]>
To: [email protected]
Subject: Re: COPY documentation with regard to references constraints
Date: Thu, 31 Oct 2024 13:15:34 +0100
Message-ID: <CAFCRh-9dwBkb73x+ckFCn-SDy=n8Fpg3XcGfFAT+MWOm+jp-Tw@mail.gmail.com> (raw)
In-Reply-To: <[email protected]>
References: <[email protected]>

On Thu, Oct 31, 2024 at 1:04 PM Bruno Wolff III <[email protected]> wrote:
> I was unable to find any documentation clarifying if using COPY to load a
> table with rows referencing others rows in the same table, whether I
> had to worry about ordering of the input.
> What I found (in 17) is that even if the references constraint wasn't
> set as deferrable, I could have rows for children before their parents
> in the COPY data and things still worked.

AFAIK, DEFERRABLE is for temporary violations crossing statement boundaries,
to postpone the enforcement of FKs at COMMIT time of the transaction.

While a single COPY is just one statement, so whether a temporary violation
for self-referential FKs would occur would be implementation-dependent,
and thus "neither logical" nor predictable.

Applies to other statement types too.

But of course, more authoritative answers will come I'm sure. --DD






view thread (2+ messages)  latest in thread

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected], [email protected]
  Subject: Re: COPY documentation with regard to references constraints
  In-Reply-To: <CAFCRh-9dwBkb73x+ckFCn-SDy=n8Fpg3XcGfFAT+MWOm+jp-Tw@mail.gmail.com>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox