Reasons for differing comparison results

When comparing two sets of input date, it is possible that different compare types (FILE, LINE, WORD, and BYTE) gives slightly different results.

In order for SuperC to detect only the types of differences that are of interest to you, make sure that you are using the most appropriate compare type and, if necessary, the appropriate process options and process statements to select only the data that you actually want compared.

Here are some of the reasons why different compare types can produce different results:

FILE and BYTE comparisons inspect the complete file (every byte) for differences. LINE and WORD comparisons use designated columns that are either specified by you or are within the default range of columns assigned by SuperC.
For example, a FILE comparison of a file with fixed-length records of eighty bytes compares all columns (that is, all bytes), whereas a LINE comparison of the same file compares columns 1 to 72 (the default). Since the sequence number columns in the file are ignored in the LINE compare, the final results can be different. In this case, for consistent results, specify the LINE compare type and the NOSEQ process option.
LINE comparisons "pad" the shorter records with spaces when comparing files with different record lengths. However, BYTE comparisons only "recognize" spaces when they are already present in the input file.
For files with input line lengths <= 256, a LINE comparison is performed after padding the lines to the longest line length. Consequently two lines, originally of unequal length, compare equally only if the spaces at the end of the longer line coincide with the shorter line's space padding.
For files with input line lengths > 256, a LINE comparison is performed on the lines without space padding. As a result, lines of unequal length are always a mismatch.
Different compare types have different sensitivity to being resynchronized. Synchronization for a LINE comparison begins at the beginning of a line and ends at the end of a line. Synchronization for a WORD comparison begins anywhere on a line on any word boundary and ends at the end of a word. Synchronization for a BYTE comparison extends only one byte anywhere on a line.
LINE comparisons detect lines that have been reformatted. However, reformatted lines have no effect on WORD comparisons as spaces and blank lines are ignored.
Results may differ depending on which input file is specified as the "new" file and which is specified as the "old" file. The matching algorithm is sensitive to the largest matched set it finds between files. There may be occasions where more than one set of matched data meets this criteria. The rules for deciding which set to choose among the equals depends upon the contents of each file and which file was nominated as the "new" file.