Object-oriented database management systems (OODBMS) or documented-oriented databases such as native XML databases provde more flexibility in data modeling. OODBMs are databases designed specifically for working with object-oriented values, thus eliminating the need for converting data to and from its SQL form, as the data is stored in its original object representation and relationships are directly represented, rather than requiring join tables/operations.
The equivalent of ORMs for document-oriented databases are called object-document mappers (ODMs).