$select = $source->select(where)->follow(LINK) # All linked objects to those that matched the select.

->bulk_insert

strive LIMIT => sub { ... };

Strive will do the operation, tracking all row fields that have been read. Once
done it will start a transaction, then verify nothing read previously has
changed. If nothing that was read in the block is changed in the DB from when
it was read prioer to the transaction, then any changes made in the block will
be written. If things changed in the DB after they were read, but before the
transaction, then nothing is written and it tries again up to LIMIT times.

my $iter = shotgun(...)

run several queries asynchronously (aside), the iterator fetches results as they come
in.
