Basic System DMS PROC › SELECT Command › DSCL SELECT CRITERIA Field Name Descriptions › USEDT — Last Use date (date format)

USEDT — Last Use date (date format)

Comparison dates can be entered in any acceptable CA Disk format. For non-VSAM data set processing, and reporting on VSAM components with SCAN REALVOLS, REPORT COMPONENTS, the value of USEDT is set to the location indicated by CA Disk system parameter DSCBLUSD in the Format-1 DSCB for each data set or component. For more details, see the system parameter description for DSCBLUSDnnnk in the Systems Guide.

For all other processing of VSAM clusters and its components, the value of USEDT is set to the location pointed to by CA Disk sysparm DSCBLUSD in the Format-1 DSCB for the first data component of each cluster. But this field is filled in only for clusters cataloged in ICF catalogs. Consult the appropriate personnel at your own installation to determine if last use dates are being maintained by either IBM routines or the enhanced routines supplied with CA Disk. If they are not, you should not use this field name for VSAM clusters.

To ensure that data sets without a last use date do not get archived when last use criteria are specified, invalid values are assigned a value of 2155366, a high date. To maintain compatibility, the old invalid date of 31DEC1999 or 99365 will be accepted until the cutoff date of 01JAN1999 or 99.001. The 99365 date will be converted to 2155366 if it is the object of USEDT or F1USEDT comparisons. The NEW invalid USEDT or F1USEDT value is 0, zero, or 2155366 or 2155.366. Either of these values can be used now to search for zero and invalid USEDTs.

Note: We recommend conversion begin immediately, so that you can begin treating USEDTs of 99365 as real beginning on 99.001. This will also assist you during testing with IPL dates GE 99.001.

For example, to select data sets with zero and invalid last use dates, use:

SELECT CRITERIA=(USEDT,EQ,31DEC1999)

Works until IPL dates GE 99.001.

SELECT CRITERIA=(USEDT,EQ,0)

Works now and in future.

SELECT CRITERIA=(USEDT,EQ,2155.366)

Works now and in future.

To select data sets and clusters cataloged in ICF catalogs with date stamping turned on but not used in the last 30 days, use:

SELECT CRITERIA=(USEDT,LE,TODAY-30)

Note: This will NOT select data sets and clusters without last use dates.

For improved performance, see F1USEDT—Format-1 DSCB last used date (date format).

For more information, see Midnight "Rapid Aging" Problems.