Reply-To: jesper.pedersen@redhat.com
Subject: Re: pg_upgrade: Pass -j down to vacuumdb
To: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>,
 "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>
Cc: Bruce Momjian <bruce@momjian.us>
References: <11b6b108-6ac0-79a6-785a-f13dfe60ab92@redhat.com>
 <ba90295e-9734-07bc-3453-bfa878948478@2ndquadrant.com>
From: Jesper Pedersen <jesper.pedersen@redhat.com>
Organization: Red Hat
Message-ID: <2dc5eaeb-e60d-2a16-696e-7b4d3d3548cb@redhat.com>
Date: Wed, 2 Jan 2019 14:47:15 -0500
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Hi,

On 12/29/18 10:03 AM, Peter Eisentraut wrote:
> On 21/12/2018 11:12, Jesper Pedersen wrote:
>> Here is a patch that passes the -j option from pg_upgrade down to
>> vacuumdb if supported.
> 
> It's not clear to me that that is what is usually wanted.
> 
> The point of the post-upgrade analyze script is specifically to do the
> analyze in a gentle fashion.  Mixing in parallelism would seem to defeat
> that a bit.
> 

Well, that really depends. The user passed -j to pg_upgrade in order for 
the upgrade to happen faster, so maybe they would expect, as I would, 
that the ANALYZE phase would happen in parallel too.

At least there should be a "notice" about what the script will do in 
this case.

Best regards,
  Jesper