In most cases, tape units will be used to store the intermediate output of the individual sorts and intermediate merges. However, it may be desirable in some circumstances to place intermediate output on disk. Assigning the intermediate output to a mass storage subsystem will not compromise the sort’s efficiency. Because these files will be written and read sequentially, paging will be minimal.
If disk is used for intermediate storage, the following rules should be observed:
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The SORTOU00 statement should not be coded.
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SORTOUnn data sets must be permanent data sets if breakpoint/restart is to be attempted.
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To determine how many SORTOUnn DD statements to supply, divide the total number of bytes of sort input data by the number of bytes of SORTWK space and add 2 to the result. This figure is the number of SORTOUnn statements to supply. If too few SORTOUnn DD statements are supplied, MAXSORT will terminate for restart at the point at which a new DD statement is needed.
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Each SORTOUnn DD statement must allocate enough primary and secondary space to hold all of the data written during that intermediate sort.
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Extended format data sets are not supported for disk SORTOUnn data sets.
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Track overflow is not supported for disk SORTOUnn data sets. Record lengths must not exceed the track capacity unless VS or VBS records are being processed.