Re: EDB builds Postgres 13 with an obsolete ICU version

On Tue, Aug 18, 2020 at 11:39 AM Magnus Hagander <magnus@hagander.net> wrote:
>
> On Tue, Aug 18, 2020 at 11:24 AM Dave Page <dpage@pgadmin.org> wrote:
>>
>> On Mon, Aug 17, 2020 at 7:23 PM Bruce Momjian <bruce@momjian.us> wrote:
>>>
>>> On Mon, Aug 17, 2020 at 04:55:13PM +0100, Dave Page wrote:
>> I wasn't aware that ICU had the concept of collation versions internally (which Michael seems to have confirmed
downthread).That would potentially make the number of users needing a reindex even smaller, but as you point out won't
helpus for years as we don't store it anyway. 
>
> It does -- and we track it in pg_collation at this point.
>
> I think the part that Michael is referring to is we don't track enough details on a per-index basis. The suggested
changes(in the separate thread) are to get rid of it from pg_collation and move it to a per-object dependency. 
>
> (And fwiw contains a patch to pg_upgrade to at least give it the ability to for all old indexes say "i know that my
icuis compatible". But yeah, the full functionality won't be available until upgrading *from* 14) 

Indeed, when upgrading from something older than 14, all indexes would
be marked as depending on an unknown collation version as in possibly
corrupted.