package Main;

my $dbh = connect.....
my $sth_cache;
$sth_cache->{query1} = $dbh->prepare_cached('SELECT foo FROM bar WHERE foo = ?');
$sth_cache->{query2} = $dbh->prepare_cached('SELECT foo1 FROM bar1 WHERE foo1 = ?');
END{
    $sth_cache->{$_}->finish for keys %{$sth_cache};
    $dbh->disconnect if $dbh;
}

#blah

sub widget {
    $sth_cache->{query1}->execute($bind_value_for_foo_WHERE_clause);
    $res = sth->fetchall_arrayref();
    # blah
}