QueryRewriter rewrites and transforms queries.
our $verbs
my $quote_re
my $bal
my $olc_re
my $mlc_re
my $vlc_re
my $vlc_rf
sub new
sub strip_comments
sub shorten
sub __shorten
sub fingerprint
sub distill_verbs
sub __distill_tables
sub distill
sub convert_to_select
sub convert_select_list
sub __delete_to_select
sub __insert_to_select
sub __insert_to_select_with_set
sub __update_to_select
sub wrap_in_derived
sub _d