Using the SELECT STATISTICS Command with Archived Statistics
Connect:Direct® for z/OS® provides a means of issuing the SELECT STATISTICS command against archived statistics. To make archived statistics available to SELECT STATISTICS, you must put the archived statistics in the format of a statistics file pair. You must make available a VSAM entry-sequenced cluster with a paired VSAM key-sequenced cluster containing the index information.
For example, if the records are archived to a magnetic tape file, you must first copy the archived records to a VSAM ESDS. Then you can run the DGADBKEY utility to build the required associated VSAM KSDS. Refer to Program Directory for IBM Connect:Direct for z/OS and Planning DASD Requirements in IBM Connect:Direct for z/OS Configuration Guide for information about the characteristics and relative sizes of the keyed and entry-sequenced clusters of a file pair. See DGADBKEY for an explanation and example of the DGADBKEY utility.
Use the ARCHDSN parameter of the SELECT STATISTICS command to search archive files. The ARCHDSN parameter names only the key-sequenced clusters of the archive pairs; IBM Connect:Direct locates the associated entry-sequenced clusters using control information in the key-sequenced clusters.
IBM Connect:Direct does not examine the statistics file pair list of the DTF when using the ARCHDSN parameter. IBM Connect:Direct only searches the archive files. SELECT STATISTICS processing does not let you name files currently in the file pair list of the DTF in the ARCHDSN parameter or combine archive files with files in the file pair list. Refer to the IBM Connect:Direct for z/OS User Guide for a description of the SELECT STATISTICS command and the ARCHDSN parameter.