in reply to mysql's join too slow; using Perl to compare two tables

why not
my $st_select = q~SELECT product_id FROM catalog WHERE author = ? AND title = ? AND label = ? AND description = ? AND price = ?~; my $sth = $dbh->prepare($st_select) or die $dbh->errstr(); for my $arrayref(@data_from_txt){ $sth->execute(@$arrayref) or die $dbh->errstr(); unless($sth->fetchrow_array()){ print "This is not in catalog: ",Dumper($arrayref); } }

in @data_from_txt all information from the txt with an arrayref for each dataset...