Feature request generators (sequences) in MariaDB

Feature request generators in MariaDB. This is needed for generating unique indexes in multi database environment. For example we have some departments with own databases each database have prefix in ID. For example a1, a2, a3 ..., c1, c2, c3 in this case we can easy consolidate all the data in one table.

Generator example: http://www.firebirdsql.org/manual/generatorguide-sqlsyntax.html