13.10 Tracing PLVfile Activity

PLVfile offers a standard PL/Vision toggle to allow you to dynamically turn on or off a trace of PLVfile activity. The triumvirate of programs for this toggle is:

PROCEDURE show;
PROCEDURE noshow;
FUNCTION showing;

When you call PLVfile.show, the trace is turned on (the default is that the trace is not active). Currently, PLVfile offers a trace of the get_line and put_line actions only.

It can be very frustrating to work with UTL_FILE and, by extension, PLVfile. You might think that you have taken all the necessary steps to perform file I/O, but you keep getting "Invalid Operation" errors. The PLVfile trace may well be able to give you the information you need to identify your problem more easily.