in reply to How to report call stack for DBI queries
update: whoops, read the note way too quickly. Thought you wanted a trace of what's going on in the prepare calls; the advice stands for that usage, but not for the poster's question!
Check out the DBI's trace method, which is simple to set up:
my $db = DBI->connect(#blah blah blah"); # trace level (1-9), and output (STDERR if not specified) $db->trace(2, '/tmp/trace.log');
I find level 2 to be of general use while debugging harder problems, 3 when 2 doesn't reveal enough, but I've never needed to go any higher. As the docs used to say, 6 really is too high to be useful, but I suppose it's there for a reason =)
If not P, what? Q maybe?