The System/38™-compatible query utility (Query/38) can be used with DDM to create and use interactive or batch query applications.
If the target server is an iSeries™ server or a System/38, most of these functions can be performed as though the remote file is a local file. When creating or changing a Query/38 application and the remote file is a logical file, the following consideration applies: either DDM files referring to each remote based-on file must exist on the source server, and the DDM file and library names must match those of the remote based-on files; or, alternatively, physical files with the same file and library names and the same record formats as the remote based-on files must exist on the source server. Because only the record formats are needed from the physical files, they need not contain data. Using this alternative, if the record formats of the remote based-on files are changed, the record formats on the source server must also be changed so that the record formats match.
If the target system is not an iSeries server or a System/38, you should refer to a local file for the format and fields that describe the data in the remote file, and then use the Override Database File (OVRDBF) command to override the local file with a DDM file when the Query/38 application is run. The local file used to create (or re-create) the query must have the same record format name as the source description of the non-iSeries or non-System/38 target file. The default record format name is the name of the source DDM file.
Although Query/38 can create an application that uses a file on a non-iSeries or non-System/38 system, the default field descriptions created on the source iSeries server for the non-iSeries remote file probably would be too general to be useful. (These files appear to be physical files with one member, whose member name is the same as the file name. The file has one record format and within that format: one field for the entire record, if it is a nonkeyed file; two fields for keyed files, one for the key and one for the remainder of the record; or more than two fields for keyed files with separate key fields.)