Undoes all the changes you made to the database since the last
       COMMIT or ROLLBACK statement, or since your first READY if you
       have not done a ROLLBACK or a COMMIT. The ROLLBACK statement
       performs a Oracle CODASYL DBMS or relational rollback and
       releases all collections associated with Oracle CODASYL DBMS
       domains and records and with relational domains and relations.
       ROLLBACK then readies Oracle CODASYL DBMS realms again or
       finishes and starts a new relational source transaction.

       The ROLLBACK statement also acts as an ABORT in procedures,
       nested statements, and command files.

       The ROLLBACK statement affects all readied parts of Oracle
       CODASYL DBMS and relational databases, whether or not you made
       any changes to the data they contain. Domains based on RMS files
       are not affected by the ROLLBACK statement.

       Format

         ROLLBACK

1  –  Example

       The following example for the Oracle CODASYL DBMS database
       PARTS_DB connects an employee named Hill to a part LA36 in the
       RESPONSIBLE_FOR set. The ROLLBACK statement undoes the change:

       DTR> FIND E IN EMPLOYEES WITH EMP_LAST_NAME = "HILL"
       DTR> SELECT 1
       DTR> FOR P IN PART WITH PART_DESC = "LA36"
       CON>     CONNECT P TO E.RESPONSIBLE_FOR
       DTR>  ROLLBACK
       DTR>