Each time file processing occurs the fields of the catalog entry which have changed because of the processing are updated. Such fields are, for example, the ACC-DATE (date of last access) and ACC-COUNT (access counter) fields for input files. Such fields are, e.g., the fields ACC-DATE (“date of last access”) and ACC-COUNT (access counter) for input files.For output files, the file and processing attributes are written into the catalog entry, and the volume list, the extent list, and the file size (for disk files: HIGH-US-PA; for tape files: BLK-COUNT) are updated.
For disk files which are not locked, the storage space allocation can be changed at any time with the FILE macro (operand SPACE) or the MODIFY-FILE-ATTRIBUTES command. Occupied pages cannot be released. If a disk file is not locked, its protection attributes can be changed with the CATAL macro or the MODIFY-FILE-ATTRIBUTES command. In the case of tape files, the protection attributes are written into the labels when the file is opened for the first time and cannot be changed freely after this.