Is it worth indexing a varchar(32) column of UUIDS where half the UUIDS are v1 and half are v4?
Both v1 and v4 (or the mix) UUIDs will build a good B+ tree index for faster SELECTs.
From normalization point of view duplicating the column is a bad idea. But if we put this aside, and any SELECTs will benefit from the new index, and impact on writes is acceptable - why not?