Almost every VSAM file SELECT we have is coded as below:
SELECT HISTORY-FILE
ASSIGN TO GCR05KSD
RECORD KEY IS HST05-KEY
ORGANIZATION IS INDEXED
ACCESS IS DYNAMIC
FILE STATUS IS HISTORY-STATUS.
That is, with ACCESS IS DYNAMIC. This despite the fact that the file is opened
only once, for INPUT:
OPEN INPUT HISTORY-FILE.
I'm concerned that this results in less efficient I/O. In particular, that it
results in more CPU usage than if the ACCESS were changed from DYNAMIC to
SEQUENTIAL. The READ is of the form:
READ HISTORY-FILE NEXT RECORD INTO HISTORY-RECORD
AT END MOVE 'Y' TO HISTORY-FILE-EOF-SW.
>From what I can tell, sometime in the past, some programming manager made
>ACCESS IS DYNAMIC a required standard for all VSAM files. I guess for
>"flexibility". Does this make any significant difference in terms of CPU usage
>at all?
John McKown
Systems Engineer IV
IT
Administrative Services Group
HealthMarkets(r)
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