9. A system comprising: models for implementing object-centric data models; one or more processors; one or more non-transitory computer readable storage media; and logic configured for: obtaining, at an importing site, an exporting site ontology and a set of one or more database changes associated with an exporting site; wherein the exporting site ontology defines one or more first object types and one or more first link types relating two or more objects of the one or more first object types in a first object-centric data model; obtaining an ontology map comprising at least one rule for mapping the one or more first object types of the first object-centric data model to one or more second object types and one or more second link types in a second object-centric data model defined by an importing site ontology and at least one link rule for mapping the one or more first link types of the first object-centric data model to one or more second link types in the second object-centric data model; incorporating the set of one or more database changes into a database at the importing site based on the at least one object rule and the at least one link rule, wherein at least one link represented in the set of one or more database changes is reversed based on the at least one rule; wherein object data for at least one object is represented by different object types in the first object-centric data model and the second object-centric data model.
9. A system comprising: models for implementing object-centric data models; one or more processors; one or more non-transitory computer readable storage media; and logic configured for: obtaining, at an importing site, an exporting site ontology and a set of one or more database changes associated with an exporting site; wherein the exporting site ontology defines one or more first object types and one or more first link types relating two or more objects of the one or more first object types in a first object-centric data model; obtaining an ontology map comprising at least one rule for mapping the one or more first object types of the first object-centric data model to one or more second object types and one or more second link types in a second object-centric data model defined by an importing site ontology and at least one link rule for mapping the one or more first link types of the first object-centric data model to one or more second link types in the second object-centric data model; incorporating the set of one or more database changes into a database at the importing site based on the at least one object rule and the at least one link rule, wherein at least one link represented in the set of one or more database changes is reversed based on the at least one rule; wherein object data for at least one object is represented by different object types in the first object-centric data model and the second object-centric data model. 16. The system of claim 9 , wherein the ontology map comprises a one-to-one mapping between a first particular link data type defined by the exporting site ontology and a second particular link data type defined by the importing site ontology; wherein a particular rule of the at least one link rule further specifies that a link represented by data of the first particular link data type should be reversed before data representing the link is incorporated into the database; wherein incorporating the set of one or more database changes into the database comprises reversing a link represented by a particular database change of the set of database changes before incorporating the particular database change into the database.