From: Christoph Berg <myon@debian.org>
To: Julien Rouhaud <rjuju123@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>
Cc: Thomas Munro <thomas.munro@gmail.com>
Cc: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Cc: Robert Haas <robertmhaas@gmail.com>
Cc: Laurenz Albe <laurenz.albe@cybertec.at>
Cc: Douglas Doole <dougdoole@gmail.com>
Cc: Pg Hackers <pgsql-hackers@postgresql.org>
Subject: Re: Collation versioning
Date: Tue, 8 Sep 2020 21:33:26 +0200
Message-ID: <20200908193326.GA108231@msg.df7cb.de> (raw)
In-Reply-To: <20200908144507.GA57691@nol>
References: <20200708062620.GD18003@paquier.xyz>
<13b0c950-80f9-4c10-7e0f-f59feac56a98@2ndquadrant.com>
<CAOBaU_Z1GgiiK__F2DbBzDM+xBb9Nxbe=4zszoOihRaZLyjNtA@mail.gmail.com>
<CA+hUKGKyL0B9Yz4cBBh7Yi-2UQ6XLLGifB0zxrPc1qxuh-KTEQ@mail.gmail.com>
<20200813095204.f7mlgdzsbaxa3mzr@nol>
<CA+hUKGLP-aW+K_PUCPbTy=g18yC=7UjurXXwiqYwTbtj3SwukA@mail.gmail.com>
<20200814073746.GF2057@paquier.xyz>
<20200814090235.ifld2qvaw43pzpzg@nol>
<20200907031741.GK2455@paquier.xyz>
<20200908144507.GA57691@nol>
Re: Julien Rouhaud
> Here's the rationale for this new flag, extracted from the patch's commit
> message:
>
> Add a new amnostablecollorder flag in IndexAmRoutine.
>
> This flag indicates if the access method does not rely on a stable collation
> ordering for deterministic collation, i.e. would not be corrupted if the
> underlying collation library changes its ordering. This is done this way to
> make sure that if any external access method isn't updated to correctly setup
> this flag it will be assumed to rely on a stable collation ordering as this
> should be the case for the majority of access methods.
>
> This flag will be useful for an upcoming commit that will add detection of
> possibly corrupted index due to changed collation library version.
Hmm. Does that flag gain us much? What about non-collation locale
changes that might still affect indexes like lower() and the citext
extension? That still depends on locale changes, but that flag
wouldn't be able to help with "this index is (not) affected by this
locale change".
IOW, I think we should aim at simply tracking the version, and leave
it to the admin (with the help of supplied SQL queries) to either
rebuild indexes or waive them.
Or maybe I misunderstood the problem.
Christoph
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: pgsql-hackers@postgresql.org
Cc: myon@debian.org, rjuju123@gmail.com, michael@paquier.xyz, thomas.munro@gmail.com, peter.eisentraut@2ndquadrant.com, robertmhaas@gmail.com, laurenz.albe@cybertec.at, dougdoole@gmail.com
Subject: Re: Collation versioning
In-Reply-To: <20200908193326.GA108231@msg.df7cb.de>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox