I'm working on migration from 4.4 to 5.22. Currently, as I am following the documentation, I have a part that confuses me regarding the "preparing the indexes".
So, since index-backed constraint should be created before the migration as mentioned in the documentation, how am I supposed to have existing UNIQUE constraint associated with newly created indexes that comes instead of BTREE indexes, since I am not supposed to delete BTREE indexes manually and there can be only one constraint per label property?
My guess is that I need to add those constraints after the migration is done, since the existing ones will be removed with BTREE indexes removal, but I'm confused cause it is mentioned in the documentation as it can be solved somehow before the migration.
You prepare the Constrains and Indexes with correct 5.x version syntax. After all the upgrading is done and the database is created via system, then you can run constraints and indexes. This is what I did and it worked.
I've tried that, but I ran into the following problem:
Caused by: java.lang.IllegalStateException: Migration will remove all BTREE indexes and constraints backed by BTREE indexes. To guard against unintentionally removing indexes or constraints, it is recommended f
or all BTREE indexes or constraints backed by BTREE indexes to have a valid replacement. Indexes can be replaced by RANGE, TEXT or POINT index and constraints can be replaced by constraints backed by RANGE inde
x. Please drop your indexes and constraints or create replacements and retry the migration. The indexes and constraints without replacement are: ...
So the point is, I have created all replacements for BTREE indexes, but there are still uniqueness constraints that are connected to the existing btree indexes. Did you run the migrate command with --force-btree-indexes-to-range or did you drop manually all constraints backed by BTREE and replaced them with new ones?