Release 10.1A: OpenEdge Deployment:
Managing 4GL Applications

Database CRCs and time stamps

At run time, OpenEdge must ensure that r-code files and the database(s) that they access are compatible. Otherwise, if the schema has changed since the code was compiled, running the code might damage the database. OpenEdge supports two techniques for checking this compatibility—cyclic redundancy check (CRC) validation and time stamp validation. Each technique prevents you from running unauthorized or data-incompatible procedures against a particular database environment.