The expressiveness of various object-oriented languages is investigated with respect to their ability to create new objects. We focus on database method schemas (dms), a model capturing the data manipulation capabilities of a large class of deterministic methods in object-oriented databases. The results clarify the impact of various language constructs on object creation. Several new constructs based on expanded notions of deep equality are introduced. In particular, we provide a tractable construct which yields a language complete with respect to object creation. The new construct is also relevant to query complexity. For example, it allows expressing in polynomial time some queries, like counting, requiring exponential space in dms alone.