We recommend that you use separate predicates for various numbers of key columns provided. This practice lets DB2 have matching index access for each combination of key parts provided.
First key access:
WHERE COL1 = WS-COL1
Two keys provided:
WHERE COL1 = WS-COL1 AND COL2 = WS-COL2
Three keys provided:
WHERE COL1 = WS-COL1 AND COL2 = WS-COL2
This practice increases the number of SQL statements that are coded within the program, but it also increases statement performance.
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