There is a case that incompatible change is introduced at new release. It is announced by release announce if new release contains such a incompatible change.
Here is the list of recommended way of upgrading Mroonga from old release.
See following URL about upgrade sequence if you use previous version.
If you upgrade prior to 1.20, refer to
If you upgrade from 1.20, refer to
If you upgrade from 2.00 or 2.01, refer to
If you upgrade from 2.00 or later and using multiple column indexes
on storage mode, refer to
If you upgrade from 2.04 or later and using SET column or ENUM that
has the number of elements < 256 in Storage mode, refer to
If you upgrade from 2.05 or later and using multiple column indexes
against VARCHAR or CHAR, refer to
If you upgrade from 2.08 or later and using TIMESTAMP column, please
recreate database. If you upgrade from 2.08 or later and using CHAR(N)
as primary key, please recreate index. Refer to
release-2-09 for each
If you upgrade prior to 5.03 and satisfies following the conditions,
and upgrade schema.
server-variable-mroonga-default-parseras server variable