Horton

Re: Collation versioning

Julien Rouhaud <rjuju123@gmail.com>

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From: Julien Rouhaud <rjuju123@gmail.com>
To: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Cc: Christoph Berg <myon@debian.org>, Michael Paquier <michael@paquier.xyz>, Thomas Munro <thomas.munro@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Laurenz Albe <laurenz.albe@cybertec.at>, Douglas Doole <dougdoole@gmail.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2020-09-10T19:27:40Z
Lists: pgsql-hackers 
On Thu, Sep 10, 2020 at 6:52 PM Peter Eisentraut
<peter.eisentraut@2ndquadrant.com> wrote:
>
> On 2020-09-08 21:33, Christoph Berg wrote:
> > 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.
>
> It's certainly safer to track dependency for all indexes and then
> carefully create exceptions afterwards.

Do you mean storing the collation version even when those are not
relevant, and let client code (or backend command) deal with it?  This
would require to store a dependency per index and column (or at least
if it's a column or an expression to avoid bloating the dependencies
too much), as it's otherwise impossible to know if a version mismatch
can be safely ignored or not.
I'm also wondering how much more complexity it would add to people who
want to actively monitor such mismatch using SQL queries.

Commits

  1. Doc: Document known problem with Windows collation versions.

  2. Add collation versions for FreeBSD.

  3. Tolerate version lookup failure for old style Windows locale names.

  4. Track collation versions for indexes.

  5. Add pg_depend.refobjversion.

  6. Remove pg_collation.collversion.

  7. Fix the MSVC build for versions 2015 and later.

  8. Add collation versions for Windows.

  9. Implement type regcollation

  10. Use libc version as a collation version on glibc systems.

  11. Make type "name" collation-aware.