Horton

Re: using index or check in ALTER TABLE SET NOT NULL

David Rowley <david.rowley@2ndquadrant.com>

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From: David Rowley <david.rowley@2ndquadrant.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Sergei Kornilov <sk@zsrv.org>, Andres Freund <andres@anarazel.de>, Robert Haas <robertmhaas@gmail.com>, David Steele <david@pgmasters.net>, PostgreSQL mailing lists <pgsql-hackers@postgresql.org>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Stephen Frost <sfrost@snowman.net>, Ildar Musin <i.musin@postgrespro.ru>
Date: 2019-05-03T23:06:46Z
Lists: pgsql-hackers 
On Thu, 2 May 2019 at 14:22, David Rowley <david.rowley@2ndquadrant.com> wrote:
>
> On Thu, 2 May 2019 at 13:08, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> >
> > Not a blocker perhaps, but it's better if we can get new behavior to
> > be more or less right the first time.
>
> It's not really new behaviour though. The code in question is for
> ATTACH PARTITION and was added in c31e9d4bafd (back in 2017).
> bbb96c3704c is the commit for using constraints to speed up SET NOT
> NULL. The mention of using the constraint for proof was made DEBUG1 in
> the initial commit.  What we need to decide is if we want to make
> ATTACH PARTITION's INFO message a DEBUG1 in pg12 or not.

FWIW, I'm in favour of changing ATTACH PARTITION's INFO messages to
DEBUG1 for PG12 to align it to what bbb96c3704c did.

Anyone else?

-- 
 David Rowley                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services

Commits

  1. Avoid using INFO elevel for what are fundamentally debug messages.

  2. Revert setting client_min_messages to 'debug1' in new tests.

  3. Allow ALTER TABLE .. SET NOT NULL to skip provably unnecessary scans.

  4. Improve predtest.c's internal docs, and enhance its functionality a bit.