Index example: Ordering and grouping on the same columns with ALWCPYDTA(*OPTIMIZE) and a unique-weight sort sequence table
Ordering and grouping on the same 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 JOB, SALARY
When using the OPNQRYF command, specify:
OPNQRYF FILE((STAFF)) FORMAT(FORMAT3)
GRPFLD(JOB SALARY)
KEYFLD(JOB SALARY)
SRTSEQ(*LANGIDUNQ) LANGID(ENU)
ALWCPYDTA(*OPTIMIZE)
The system can use UNQIX2 to satisfy both the grouping and ordering requirements. If index UNQIX2 did not exist, the system does one of the following actions:
- Create an index using a sort sequence table of *LANGIDUNQ or
- Use index HEXIX2 to satisfy the grouping and to perform a sort to satisfy the ordering