The RDB$VIEW_RELATIONS system table lists all the tables that
    participate in a given view. There is one row for each table
    or view in a view definition. The following table provides
    information on the columns of the RDB$VIEW_RELATIONS system
    table.

                                Data
    Column Name                 Type      Summary Description

    RDB$VIEW_NAME               char(31)  Names a view or table that
                                          uses another table. The
                                          value of RDB$VIEW_NAME is
                                          normally a view name, but
                                          might also be the name of
                                          a table that includes a
                                          column computed using a
                                          statistical expression.
    RDB$RELATION_NAME           char(31)  The name of a table used to
                                          form the view.
    RDB$VIEW_CONTEXT            integer   An identifier for the
                                          context variable used
                                          to identify a table in
                                          the view. The context
                                          variable appears in the
                                          BLR represented by the
                                          column RDB$VIEW_BLR in
                                          RDB$RELATIONS.
    RDB$SECURITY_CLASS          char(20)  Reserved for future use.