Maintenance for Query (QRY) Access Paths

Tailoring for Performance › Access Path Maintenance (Immediate, Delay, or Rebuild) › Maintenance for Query (QRY) Access Paths

Maintenance for Query (QRY) Access Paths

For Query (QRY) access paths, the access path maintenance option is approximated using the OPTIMIZE parameter on the i OS Open Query File OPNQRYF command. The OPTIMIZE parameter indicates the optimization goal the system is to use when satisfying the QRY access path specifications.

The following table gives a brief description of each OPTIMIZE parameter value and shows the corresponding access path maintenance option:


OPNQRYF Command OPTIMIZE Parameter Values (for QRY Access Paths)		Corresponding Access Path Maintenance Option
*FIRSTIO	The system attempts to improve the time required to open the file and to retrieve the first buffer of records from the file.	*IMMED
*MINWAIT	The system attempts to minimize delays when reading records from the file.	*DLY
*ALLIO	The system attempts to improve the total time to process the whole query, assuming that all query records are read from the file.	*REBLD

For more information:

On QRY access paths, see Recognizing the Basic Properties of Access Paths in the "Access Paths: An Introduction" chapter and Adding a Query (QRY) Access Path in the "Adding Access Paths" chapter.
On the OPNQRYF command's OPTIMIZE parameter, see IBM i Control Language Reference.

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