Message-ID: <437f45aa-b6ea-44bc-8dc3-26cfb309be29@dalibo.com>
Date: Thu, 5 Jun 2025 16:51:05 +0200
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: ALTER TABLE ADD FOREIGN KEY to partitioned table, is not
 parallelized
From: =?UTF-8?Q?Fr=C3=A9d=C3=A9ric_Yhuel?= <frederic.yhuel@dalibo.com>
To: Dimitrios Apostolou <jimis@gmx.net>
Cc: pgsql-performance@lists.postgresql.org, bruce@momjian.us,
 Christophe Courtois <christophe.courtois@dalibo.com>
References: <5f002654-92e9-8032-3e1a-134461b4e819@gmx.net>
 <e89cfa42-edeb-431e-b33a-881556583666@dalibo.com>
 <ec31717f-511b-fbf2-f6b5-ade5b3c98899@gmx.net>
 <90e55c6b-3d79-4bf8-8874-a64dd10a0286@dalibo.com>
Content-Language: fr, en-US
Autocrypt: addr=frederic.yhuel@dalibo.com; keydata=
 xjMEXn3bgxYJKwYBBAHaRw8BAQdA6tX5FT/n5ztMWIoBdl6k5avvu65fv6ryfVzIx/aH3V3N
 JEYuIFlodWVsIDxmcmVkZXJpYy55aHVlbEBkYWxpYm8uY29tPsKWBBMWCAA+FiEEi7OTyf6H
 ePS+C6n11XGWhN8zGNUFAmZDVJ8CGwMFCQtfi90FCwkIBwIGFQoJCAsCBBYCAwECHgECF4AA
 CgkQ1XGWhN8zGNV65gEA6o+UrebFjn2CIAOYwP3CiiJugiM5TMH9yJyehQua5ZoA/2ChxiVn
 8OUaAw/ErxJmQi1mSN0tNZBL/KhkUPBDUDQNzjgEXn3bgxIKKwYBBAGXVQEFAQEHQCuh5cLQ
 AtEBXHa2Fmtp0kduBu7msM7qO/gaEcdjFUdiAwEIB8J+BBgWCAAmAhsMFiEEi7OTyf6HePS+
 C6n11XGWhN8zGNUFAmZDVJ8FCQtfi90ACgkQ1XGWhN8zGNWOOAEArSqePBqfd4Kx4ulACaWO
 6fM+XSDfUlBAQXx9rU6DR4MBALwozl9g91tRysim6lKxggvBfp/PvbpTZNrxYLWB2fYP
In-Reply-To: <90e55c6b-3d79-4bf8-8874-a64dd10a0286@dalibo.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Archived-At: 
 <https://www.postgresql.org/message-id/437f45aa-b6ea-44bc-8dc3-26cfb309be29%40dalibo.com>
Precedence: bulk


On 6/5/25 16:13, Frédéric Yhuel wrote:
> 
> 
> On 6/4/25 16:12, Dimitrios Apostolou wrote:
>> In general I have noticed most operations are slower after a succesful 
>> pg_restore until VACUUM is complete, which is unfortunate as the 
>> database is huge and it takes days to run. Something I have on my list 
>> to try, is whether a COPY FREEZE would alleviate all this trouble, 
>> since all tuples are immediately visible then. Maybe a patch for a new 
>> pg_restore option --freeze is a better solution. Are my assumptions 
>> right?
> 
> It seems that the idea has already been discussed: https:// 
> www.postgresql.org/message-id/flat/ 
> CA%2BU5nM%2BXvkUu9ran%2B5cY%3DTWQquLTpvzte4KVMK%3DaDfbr- 
> xfNXA%40mail.gmail.com#b61a7fee06e10e61afa68712bc0b3c5b
> 
> I've CCed Bruce Mojman, in the hope that he can tell us more about it.
> 
> 

(It might be more interesting now than 12 years ago thanks to this 
patch: 
https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=7db0cd2145f2bce84cac92402e205e4d2b045bf2)