Yes, that would be what a database system *does* in life.
You could create a simple Access Path as a Logical file – see
DB2 Universal Database for iSeries Database Programming
contains information about the DB2 Universal Database for iSeries (DB2 UDB for iSeries) database management system, and describes how to set up and use a database on IBM ERserver iSeries 400 using traditional system interfaces.
Programming DDS for physical and logical files
Both of these, and much, much more can be found here.
you could also consider copying the two files into a single physical with the CPYF command. use it, then delete it.
Your logical would look something like this
A R FILE1R PFILE(FILE1)
A K FLD1
A K FLD2
A K FLD3
A R FILE2R PFILE(FILE1)
A K F2D1
A K F2D2
A K F2D3
Where FILE1R and FILE2R are the record names of the physical files Fields FLD1-3 are key fields from file1 and F2D1-3 are the corresponding key fields from file2. You may want to create a differnt record format for one so you can use the RENAME keyword to rename fields so they have the same field names.