sub minmax {
my ($self) = @_;
my $dbh = $self->{dbh};
- my $sth = $self->{num_minmax} ||=
- $dbh->prepare('SELECT MIN(num),MAX(num) FROM msgmap');
+ # breaking MIN and MAX into separate queries speeds up from 250ms
+ # to around 700us with 2.7million messages.
+ my $sth = $dbh->prepare_cached('SELECT MIN(num) FROM msgmap', undef, 1);
$sth->execute;
- $sth->fetchrow_array;
+ my $min = $sth->fetchrow_array;
+ $sth = $dbh->prepare_cached('SELECT MAX(num) FROM msgmap', undef, 1);
+ $sth->execute;
+ ($min, $sth->fetchrow_array);
}
sub mid_prefixes {