Ordering and grouping on different columns with ALWCPYDTA(*OPTIMIZE) and a unique-weight sort sequence table (SRTSEQ(*LANGIDUNQ) LANGID(ENU)).
SELECT JOB, SALARY FROM STAFF GROUP BY JOB, SALARY ORDER BY SALARY, JOB
When using the OPNQRYF command, specify:
OPNQRYF FILE((STAFF)) FORMAT(FORMAT3) GRPFLD(JOB SALARY) KEYFLD(SALARY JOB) SRTSEQ(*LANGIDUNQ) LANGID(ENU) ALWCPYDTA(*OPTIMIZE)
The system can use index HEXIX2 or index UNQIX2 to satisfy the grouping requirements. A sort is performed to satisfy the ordering requirements.