The OMT-G handles three types of integrity constraints:

Topological integrity constraints: Geometric properties and  definitions of spatial relations are applied to application-specific entities and relationships to provide a basis for integrity control. In OMT-G, topological integrity constraints are achieved through spatial aggregation, spatial  relations, connectivity, and geo-field integrity rules.

Semantic integrity constraints: They concern with the meaning of geographic features. These constraints are implmented in OMT-G through spatial relationship integrity rules.

User-defined integrity constraints: They are  equivalent to business rules of traditional database systems. They are implemented in OMT-G as methods associated with classes.