Schema security ensures that only authorized users can modify table, field, and index definitions. To establish schema security, use the Data Dictionary Freeze/Unfreeze utility to lock or freeze table, field, and index definitions in the database so that unauthorized users cannot make any modifications to them. Schema modifications change file time stamps, or cyclic redundancy check (CRC) values, making all procedures that reference the database invalid. After you freeze a database, no user can make any changes to it.
