Re: Collation versioning

On Thu, Sep 6, 2018 at 5:36 PM Thomas Munro
<thomas(dot)munro(at)enterprisedb(dot)com> wrote:
> On Thu, Sep 6, 2018 at 12:01 PM Peter Eisentraut
> <peter(dot)eisentraut(at)2ndquadrant(dot)com> wrote:
> > Also, note that this mechanism only applies to collation objects, not to
> > database-global locales. So most users wouldn't be helped by this approach.
>
> Yeah, right, that would have to work for this to be useful. I will
> look into that.

We could perform a check up front in (say) CheckMyDatabase(), or maybe
defer until the first string comparison. The tricky question is where
to store it.

1. We could add datcollversion to pg_database.

2. We could remove datcollate and datctype and instead store a
collation OID. I'm not sure what problems would come up, but for
starters it seems a bit weird to have a shared catalog pointing to
rows in a non-shared catalog.

The same question comes up if we want to support ICU as a database
level default. Add datcollprovider, or point to a pg_collation row?

--
Thomas Munro
http://www.enterprisedb.com