Message-ID: <83bfef0d-3e3c-e4c7-f6c4-29db5e632883@gmail.com>
Date: Thu, 2 May 2024 18:00:00 +0300
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Subject: Re: cataloguing NOT NULL constraints
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To: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Dean Rasheed <dean.a.rasheed@gmail.com>,
 Andrew Bille <andrewbille@gmail.com>, Peter Eisentraut
 <peter@eisentraut.org>, Robert Haas <robertmhaas@gmail.com>,
 pgsql-hackers@lists.postgresql.org
References: <202405011749.txscey5apbn6@alvherre.pgsql>
From: Alexander Lakhin <exclusion@gmail.com>
In-Reply-To: <202405011749.txscey5apbn6@alvherre.pgsql>
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Hello Alvaro,

01.05.2024 20:49, Alvaro Herrera wrote:
> Here are two patches that I intend to push soon (hopefully tomorrow).
>

Thank you for fixing those issues!

Could you also clarify, please, how CREATE TABLE ... LIKE is expected to
work with NOT NULL constraints?

I wonder whether EXCLUDING CONSTRAINTS (ALL) should cover not-null
constraints too. What I'm seeing now, is that:
CREATE TABLE t1 (i int, CONSTRAINT nn NOT NULL i);
CREATE TABLE t2 (LIKE t1 EXCLUDING ALL);
\d+ t2
-- ends with:
Not-null constraints:
     "nn" NOT NULL "i"

Or a similar case with PRIMARY KEY:
CREATE TABLE t1 (i int PRIMARY KEY);
CREATE TABLE t2 (LIKE t1 EXCLUDING CONSTRAINTS EXCLUDING INDEXES);
\d+ t2
-- leaves:
Not-null constraints:
     "t2_i_not_null" NOT NULL "i"

Best regards,
Alexander