my $dbh = DBI->connect ("dbi:CSV:", undef, undef, {
    f_ext                => ".csv/r",
    csv_sep_char         => "\t",
    csv_allow_whitespace => 1,
    RaiseError           => 1,
    PrintError           => 1,
    }) or die $DBI::errstr;
# due to <c>f_ext</c> there is no need to specify the filename!
my $sth = $dbh->prepare ("select * from file");