CA Compress/2 › The CA Compress/2 Utilities › Prepass › Prepass Statistics

Prepass Statistics

The printed output from the File Prepass Utility comprises the following:

• The input file's DCB information (RECFM, LRECL, BLKSIZE, and if applicable, RKP and KEYLEN).
• Record definitions (RDL statements) either specified by the user or assumed by default.
• Error messages about incorrect usage of the RDL. Each message is prefixed by an alphanumeric character, which also underscores the error in the RDL statement to which the message applies.
• The number of records Prepassed.
• The shortest, longest, and average record lengths on the Prepassed file. For fixed-length records, all three numbers are identical.

If field types C1, C2 and/or C3 are defined in the RDL for the file Prepassed (either by user specification or by default), a table is printed for each such field type defined showing the compression bit code for each of the 256 possible values containable in one byte, plus the bit code used to represent the repetition indicator. The bit codes are assigned based on the relative frequency of each byte; most frequently encountered values are assigned the shortest bit codes, and least frequently encountered values are assigned the longest bit codes.