To sort a catalogue into ascending or descending order on some (numeric) column type:
catsort generates a new sorted catalogue; it does not overwrite the existing catalogue. The
amount of textual information written to the output catalogue is controlled using the command line
mechanism described in Section 10.1. You then answer the series of prompts described below. In these
descriptions the prompts are identified by the corresponding ADAM parameter name, which appears
at the start of the prompt line.
ASCENDING’) Specify the order required for the output catalogue. The alternatives available are ‘
ASCENDING’ or ‘
DESCENDING’. Abbreviations down to and including ‘
A’ or ‘
D’ are permitted.
If a catalogue is sorted on a column which contains null values then the rows for which the column is null will appear after all the rows with a valid value. The order of such rows is unpredictable.