Method call walk-through
Consider a simple prepare call: $dbh->prepare(...)
$dbh is reference to a DBI::db object (regardless of driver)
DBI::db::prepare is an alias for DBI dispatch method
Dispatch calls driver’s prepare method something like this:
my $inner_hash_ref = … # from tie magic
my $implementor_class = … # from DBI magic data
$inner_hash_ref->$implementor_class::prepare(…)
Since driver code gets inner hash it has fast access to the hash contents