my $statement1 = "SELECT files FROM catalog WHERE words LIKE %".$word."%";
$sth1 = $dbh -> prepare($statement1);
$sth1 -> execute();

##</code><code>##

my $find_files = $dbh->prepare(q{
  SELECT files
  FROM catalog
  WHERE
    words LIKE ?
});

for my $w (@words) {
  $find_files->execute("%$w%");
  while (my ($file) = $find_files->fetchrow_array) {
    ...
  }
}

##</code><code>##

$sth2 = $dbh ->prepare("select filename, type from library
  where filename = $file_index 
  and".$rule_append);

##</code><code>##

my %search_library = (
  email => $dbh->prepare(q{
    SELECT filename, type
    FROM library
    WHERE
      filename = ?
      AND filetype = 'email'
  }),
  article => $dbh->prepare(q{
    SELECT filename, type
    FROM library
    WHERE
      filename = ?
      AND filetype = 'article'
  }),
  both => $dbh->prepare(q{
    SELECT filename, type
    FROM library
    WHERE
      filename = ?
      AND (filetype = 'email' OR filetype = 'article')
  }),
);

##</code><code>##

for my $w (@words) {
  $find_files->execute("%$w%");
  while (my ($file) = $find_files->fetchrow_array) {
    for my $f (split /:/, $file) {
      $search_library{$type}->execute($f);
      if (my @rec = $search_library{$type}->fetchrow_array) {
        $match{$rec[0]} = $rec[1];
      }
    }
  }
}