Abstract: Disclosed are a method and a system for changing a database schema. The method comprises receiving a request to make a set of changes to a first version of the database schema of a database, and creating, based on the set of changes to the first version, a conversion rule for converting data records maintained by the database between the first version and a second version of the database schema. The second version results from the application of the set of changes to the first version of the database schema. The method further comprises storing the conversion rule for retrieval when performing data operations on the data records in accordance with any database schema version in a set of supported versions comprising the first version and the second version of the database schema. Also disclosed are methods and systems for performing data operations on databases supporting multiple versions of a database schema.