Horton

Re: Collation versioning

Thomas Munro <thomas.munro@gmail.com>

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From: Thomas Munro <thomas.munro@gmail.com>
To: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Cc: Julien Rouhaud <rjuju123@gmail.com>, Douglas Doole <dougdoole@gmail.com>, Thomas Munro <thomas.munro@enterprisedb.com>, Christoph Berg <myon@debian.org>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2019-11-08T01:32:33Z
Lists: pgsql-hackers 
On Thu, Nov 7, 2019 at 1:27 AM Peter Eisentraut
<peter.eisentraut@2ndquadrant.com> wrote:
> As I was working on that lately, I came to the conclusion that we should
> get *this* patch done first.

Cool.  Let's aim to get this into 13!

> > * Some have expressed doubt that pg_depend is the right place for
> > this; let's see if any counter-proposals appear.
>
> The only alternative is to create a new catalog that contains exactly
> the same columns as pg_depend (minus deptype) plus the version.  That
> would work but it would just create a lot of code duplication, I think.

Agreed.

> One thing I've been thinking about is whether this object-version
> concept could extend to other object types.  For example, if someone
> changes the binary layout of a type, they could change the version of
> the type, and this catalog could track the type version in the column ->
> type dependency.  Obviously, a lot more work would have to be done to
> make this work, but I think the concept of this catalog is sound.

Interesting idea.  Sounds like it requires version checks that
actually stop you from using the dependent object, instead of emitting
a few meek warnings.

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.