SORT-MERGE/XL Programmer's Guide (32650-90884)

52 Chapter4
Altering the Collating Sequence
Sorting and Arranging
Sorting and Arranging
When you begin a sort, you must specify the keys, the place where records will be
compared. Then, the keys of each record are compared and put into a hierarchichal
arrangment. The resulting arrangement depends two things: the sequence and the order.
You must specify both.
The sequence determines what follows what: for example, 0,1,2,...,9 in digits. There are
predefined sequences, like the standard alphanumeric ones, or you can create your own.
Sequencing depends on the data type of the key. You pass the type in one field of the
keys
parameter. Number type keys are sorted in standard numeric order. ASCII or EBCDIC
byte types (type 0 in the
keys parameter) are sorted in their own sequences, shown in
Appendix C.
You can, however, vary the sequence of byte types if you wish. You may want an alphabetic
sequence that is not case sensitive. For example, you may want "AaBbCc..." instead of the
ASCII sequence of "ABC ... abc". You may want your EBCDIC data sorted ignoring
hyphens and punctuation, or with the digits before the letters.
The order determines which end of the sequence will come first. There are two options:
ascending or descending. For example, the digits in ascending order are: 0,1,2,...,9; the
digits in descending order are: 9,8,7,...,0.
NOTE When performing Native Language (NL) functions, alphanumeric sorting and
merging needs to be done using the specifics of the native language. See the
end of this chapter for more information.