Relativity allows the contents of COBOL data files to be modified by using the INSERT, DELETE, and UPDATE statements of ODBC SQL.
In order to support these SQL statements, the tables must be writable. The Relativity Designer must follow several rules when defining tables and their association with COBOL application files for a table to be writable. If these rules are not followed, a table can only be read.
Many of the rules will be enforced at design-time (the augmentation stage) by the Relativity Designer; others will be detected and enforced when an attempt is made to actually modify a table.
Restrictions beyond those imposed by the RDBMS may be intentionally imposed by the Relativity Designer by using the Relativity security features. Defining the Relativity security and privilege capabilities becomes much more important when the end-user of the database can modify data files; see Defining Security for Relativity Catalogs for more information.