On Fri, Nov 29, 2019 at 9:08 AM Alexander Lakhin <exclus...@gmail.com> wrote: > So for now it seems dangerous to use predefined collations as their old > versions are not preserved by pg_upgrade and the user doesn't know which > indexes affected by the actual ICU collation changes.
Yeah, we noticed this while working on a proposal for new per-database-object version dependency tracking, and Peter E has written a patch to address it: https://commitfest.postgresql.org/25/2328/
