Do I need to keep old autoMigrations lines in Room Database?

Question

Today I saw an error: A migration from [n] to [n+2] was required but not found

Question: should I keep the lines with automigrations when I have already switched to new versions. Are json files with database schemas packaged in apk and/or aab?

Is it enough to write like this?

@Database(
    entities = [Setting::class, ProfileModel::class, EventsClicks::class],
    version = 5,
    autoMigrations = [
        AutoMigration(from = 4, to = 5)
    ]
)

Or should I write like this all the time?

@Database(
    entities = [Setting::class, ProfileModel::class, EventsClicks::class],
    version = 5,
    autoMigrations = [
        AutoMigration(from = 1, to = 2),
        AutoMigration(from = 2, to = 3, spec = AppDatabase.MyAutoMigration::class),
        AutoMigration(from = 3, to = 4),
        AutoMigration(from = 4, to = 5)
    ]
)

There is no such information on https://developer.android.com/training/data-storage/room/migrating-db-versions and many other guides don't either. Could you help me understand, please?

Answer 1

That depends, if you will have an user that has the db with version 1 (didn't update the app for a long time) and no migration schema will be present from version 1 to 5, the app won't work, so keeping them might be a good idea

also, room is capable of skiping versions during migrations, as mentioned in this article, so you may shorten up the automigrations