3. Just go with it, and inform people who complain about it how to deal with the error

Another vote for door number three.

Those of us who deal with different databases are unlikely to expect

  my $rowcount = $dbh->do("SELECT * FROM TABLE");
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to be portable, and will opt for COUNT(*) (or the equivalent) instead. And those who haven't yet experienced the joys of porting database applications to different RDBMs are getting set up for an unpleasant surprise when they use that construct.