Does it really make sense for allow_transactions() to be part of the
policy or should it be a bool option passed in to insertfrom( )?
The reason I ask is because it seems silly to have to have two different
InsertPolicy objects that differ only in whether transactions are
allowed or not.
In other words, the question of whether you want transactions seems
orthogonal to how you want the insert to work.
Or was the intention that the InsertPolicy tells you whether a
transaction would be a "good idea", i.e., it may generate more than one
SQL statement?
