Index example: Ordering and grouping on the same columns with ALWCPYDTA(*OPTIMIZE) and a shared-weight sort sequence table

 

Ordering and grouping on the same columns with ALWCPYDTA(*OPTIMIZE) and a shared-weight sort sequence table (SRTSEQ(*LANGIDSHR) 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(*LANGIDSHR) LANGID(ENU) 
   ALWCPYDTA(*OPTIMIZE)

The system can use SHRIX2 to satisfy both the grouping and ordering requirements. If index SHRIX2 did not exist, the system creates an index using a sort sequence table of *LANGIDSHR.

 

Parent topic:

Examples of indexes