Thunderbird 3.1.2 Windows XP 32-bit Lightning 1.0b2 Created a Thunderbird profile, installed Lightning and still see a storage.sdb file created in the Thunderbird profile folder (seems to contain only table information, no data).
Correct, storage.sdb is still required due to compatibility reasons. For example to prevent upgrade issues if someone switches between different Thunderbird+Lightning versions.
If I remember correct you can't downgrade Lightning because it blocks the usage of lower schema versions. So moving this information to a preference should be enough to drop storage.sdb or what other information are still stored in it?
It's the other way. Each Lightning release supports only the current and past database schema. If the database schema is newer and therefore unknown it can't be used. Therefore it blocks usage. You can't change all the previously released Lightning versions that check storage.sdb.
Component: Build Config → Provider: Local Storage
You need to log in before you can comment on or make changes to this bug.