context-variable a variable name used with the records identified by the rse. rse-source the name of a readied domain or established collection. An rse source must be specified. field-name-1 the name of the field specified in rse-source-1 and rse-source-2. boolean-expression a specification of the conditions a record must meet to be included in the record stream. reduce-key a list of one or more reduce keys (see HELP REDUCE). sort-key a list of one or more sort keys (see HELP SORT). remote-domain-name the name of any remote domain. rdb-relation-name the name of the relation that is the source for the rse. rdb-domain-name the name of the relational domain that is the source for the rse. rms-domain-name the name of the RMS domain that is the source for the rse. collection-name the name of a DEC DATATRIEVE collection that is the source for the rse. list the name of a DEC DATATRIEVE list that is the source for the rse. Oracle CODASYL DBMS-record-name the name of the Oracle CODASYL DBMS record that is the source for the rse. Oracle CODASYL DBMS-domain-name the name of the Oracle CODASYL DBMS domain that is the source for the rse. set-name the name of a Oracle CODASYL DBMS set. The record type of the rse must be a participant in that set. The CROSS clause lets you make the cross product of one or more domains. If you specify the OVER clause, DEC DATATRIEVE finds the specified field in each domain and only returns the combined records if the fields are identical. For more details on CROSS see HELP CROSS. For complete information on the record selection expression see the DEC DATATRIEVE Reference Manual.