I have a term reference field called 'field_product_discount_bonus' referencing terms from the vocabulary 'discount_bonus' which is referenced by entity 'commerce_product'.
If I delete a term from that vocabulary, the database table 'field_data_field_product_discount_bonus' still holds records for the deleted term tid in 'field_product_discount_bonus_tid' and this is reflected if I use the following code to find a deleted term id:
$query = new EntityFieldQuery;
$result = $query->execute();
Surely such database records should be deleted from the system? Is there a reason to keep these records around for historical reasons, otherwise it's just taking up space.