Here is an example of using the select function within DDS. The logical file references the physical file, defining a key, and selecting only those records where the field ADHSTS contains an asterisk.
A R RADMHDR PFILE(ADMHDRPF) A K ADHOID A S ADHSTS COMP(EQ '*')
Omit is implied in the example above, but may be explicitly defined as in the sample below.
A R GPORTA PFILE(GPORTAFL) A K INVDTZ A K INVNOZ A S EXTR8H COMP(EQ ' ') A O ALL