Thanks a lot for your effort.I found what happens.I had to wrap the following in a BEGIN block at the top of the CGI script:

BEGIN { $ENV{DBI_TRACE}='15=/var/www/xx/dbitrace.log';use DBI; }

The output now shows everything including the sql statements and the data retrieved.
What does BEGIN do and why has it made such a big difference? I think it has something to do with the environment that Apache/CGI runs,like that Apache initializes something before the perl script runs? What do you think?

In reply to Re^2: DBI trace has limited output by Anonymous Monk
in thread DBI trace has limited output by Anonymous Monk

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