in reply to DBI trace has limited output

The DBI documentation says that SQL statement tracing is not implemented in DBI, but in some DBDs. That might be one line of investigation. If your database driver does not support SQL tracing you are out of luck.

Another line of investigation is whether you are enabling trace correctly. I have not used CGI in a long time, and may not be of help, but I suspect that to get help on that you will need to say how you are trying to enable tracing.