Spatial data integrity constraints in object oriented geographic data modeling

Abstract

An important activity in the design of a particular database application consists in identifying the integrity constraints that must hold on the database, and that are used to detect and evaluate inconsistencies. It is possible to improve data quality by imposing constraints upon data entered into the database. These constraints must be identified and recorded at the database design level. However, it is clear that modeling geographic data requires models which are more specific and capable of capturing the semantics of geographic data. Within a geographic context, topological relations and other spatial relationships are fundamentally important in the definition of spatial integrity rules. This paper discusses the relationship that exists between the nature of spatial information, spatial relationships, and spatial integrity constraints, and proposes the use of OMT-G, an extension of the OMT model for geographic applications, at an early stage in the specification of integrity constraints in spatial databases. OMT-G provides adequate primitives for representing spatial data, supports spatial relationships, and allows topological, semantic and user integrity rules to be specified in the database schema.

An inconsistency tolerant approach to querying spatial databases

“…In the spatial domain, some related studies address the specification of integrity constraints [6,16], and checking topological consistency at multiple representations and for data integration [11,24,12,17]. More recently, [10] proposes qualitative reasoning with description logics to describe consistency between geographic data sets.…”

Inconsistency Issues in Spatial Databases

“…In a tree-dimensional space, a polyhedra is represented by the boundaries of which contain planar facets (i.e., surfaces), polylines, and points. B A (3,9) (1,5) (3,5) [5,7], [3,5], [1,5], [3,9] > B = < [5,7], [8,7], [5,1], [3,5], [5,7] > Other types of models that concern with practical issues of efficiency are the raster model and the piano model [38] [39] [55], which are often, but not always, seen as the typical way to model a field view of the space. The raster model intentionally represents spatial information by a finite number of cells or raster points, where the infinite number of points associated with a cell share the same properties.…”

“…The difference between the two models is that the topological model handles explicitly common boundaries and adjacency between polygons. [5,7], [3,5], [1,5], [3,9] [8,7], [5,1], [3,5], [5,7] The constraint model defines any geometrical figure by an elementary geometry expressed by first-order logic over the real numbers [42]. The constraint data model aims to handle infinite relations (i.e., infinite sets of points in a space), which are represented by quantifier-free formulas.…”

“…It needs to consider the appropriate conceptual frameworks for analyzing spatial consistency [24] [30] [43] [63], such as models for consistency at multiple representational levels or granularities. It also concerns the specification language of integrity constraints [9] [41] and the design of computational-geometry algorithms to implement consistency checkers.…”

Modeling Geometric Rules in Object Based Models: An XML / GML Approach

“…The importance of spatial data integrity is addressed in Borges et al (1999), where a method for specifying 'integrity rules' within the Object Modelling Technique -G (OMT-G), a geographic applications extension to OMT, at an early stage within the database design sequence is suggested (Borges 1997). It is suggested, as in Cockcroft (1998), that the integrity rules must be enforced at data entry and update; this ensures the integrity of any state of the database.…”