Hi, with the update to glibc 2.28, collation aka sort ordering is changing:
$ echo $LANG de_DE.utf8 $ (echo 'a-a'; echo 'a a'; echo 'a+a'; echo 'aa') | sort stretch: aa a a a-a a+a buster: a a a+a a-a aa A vast number of locales is affected, including en_US, possibly all of them. For PostgreSQL, this means that the ordering of indexes on disk is becoming corrupt, and all "text" (varchar, char, ...) indexes need to be rebuilt. (And worse, if that is not done immediately, the tables might become corrupt because some tuples aren't index-visible anymore due to the incorrect btree ordering.) https://postgresql.verite.pro/blog/2018/08/27/glibc-upgrade.html https://www.postgresql.org/message-id/9cbd8ba7-899f-4ed3-92b1-902b0d245...@manitou-mail.org The PostgreSQL project is discussing how this could be handled inside the database, but a) it's totally unclear how this could be detected generically, not just for this set of test strings, and b) Debian needs a fix now, not something that might appear in PostgreSQL 12 or 13. I've been thinking about this for some time, and the best I could come up so far is "raise a debconf note that people need to invoke REINDEX DATABASE". The open question about this plan is, how should this note be triggered. Plan 1: Add a check if there are any postgresql clusters in /etc/postgresql/, and raise the warning from locales.postinst and locales-all.postinst. Plan 2: Add a trigger to postgresql-common that checks if locales(-all) are being upgraded, and raise the warning from there. (This plan has the downside that we'd need to fix postgresql-common in stretch to have the same check.) Plan 1 looks much better. I'm sorry that I didn't raise that earlier because I had hoped to come up with some smarter solution that would take some burden from the user having to run commands manually. Does that make sense? Are there any options that I missed? Are there any other packages affected? How do we proceed? Christoph
