SELECT *
FROM my_table
WHERE id_column IN (?, ?, ?, ?)

##</code><code>##

my @sths;
while (<>) {
  my @values = split ' ', $_;
  $sths[@values] ||=
    $dbh->prepare("SELECT * FROM my_table WHERE id_column IN (" .
                  join(', ', ('?') x @values) . ')');
  $sths[@values]->execute(@values);
  # ...
}