On Tue, 2024-07-23 at 06:31 -0600, Jeremy Schneider wrote: > Other RDBMS are very careful not to corrupt databases, afaik > including function based indexes, by changing Unicode. I’m not aware > of any other RDBMS that updates Unicode versions in place; instead > they support multiple Unicode versions and do not drop the old ones.
I'm curious about the details of what other RDBMSs do. Let's simplify and say that there's one database-wide collation at version 1, and the application doesn't use any COLLATE clause or other specifications for queries or DDL. Then, version 2 of that collation becomes available. When a query comes into the database, which version of the collation does it use, 1 or 2? If it uses the latest available (version 2), then all the old indexes are effectively useless. So I suppose there's some kind of migration process where you rebuild/fix objects to use the new collation, and when that's done then you change the default so that queries use version 2. How does all that work? Regards, Jeff Davis