Datamapper DataMapper → 1.1

From #datamapper

belongs_to relationships don't use get under the hood.

This means that the cache provided by identity map is bypassed with a big hit on performance.

In this example

class Store
    property :address
end

class Product
    property :location

    belongs_to :store

    # XXX: this method makes one SQL query for each invocation
    def in_original_store?
        location == store.address
    end
end

calling Product#in_original_store? a thousand times will generate a thousand queries, even when there are only two or three Store objects stored in the whole repository.