Geo-relational algebra: A model and query language for geometric database systems

Güting, Ralf Hartmut

doi:10.1007/3-540-19074-0_70

Cited by 114 publications

(62 citation statements)

References 22 publications

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“…For example, in (Güting, 1988) and (van Oosterom et al, 1994) three different distance operations are proposed: while the operation dist calculates the distance between two points, the operations mindist and maxdist calculate the minimum and maximum distance between two spatially extended objects, such as lines and regions. Another metric operator that is often found in GIS literature is called diameter.…”

Section: Metric Operatorsmentioning

confidence: 99%

Implementing Metric Operators of a Spatial Query Language for 3D Building Models: Octree and B-Rep Approaches

Borrmann

Schraufstetter

Rank

2009

J. Comput. Civ. Eng.

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A Spatial Query Language for Building Information Models enables the spatial analysis of buildings and the extraction of partial models that fulfill certain spatial constraints. Among other features, the developed spatial query language includes metric operators, i.e. operators that reflect distance relationships between spatial objects, such as mindist, maxdist, isCloser and isFarther. The paper presents formal definitions of the semantics of these operators by using point set theory notation. It further describes two possible implementation methods: the first one is based on a discrete representation of the operands' geometry by means of the hierarchical, space-partitioning data structure octree. The octree allows for the application of recursive algorithms that successively increase the discrete resolution of the spatial objects employed and thereby enables the user to trade-off between computational effort and the required accuracy. By contrast, the second approach uses the exact boundary representation (B-Rep) of both spatial objects resulting in precise distance measurements. Here the bounding facets of each operand are indexed by a so-called axis-aligned bounding boxes tree (AABB tree). The algorithm uses the AABB-tree structure to identify candidate pairs of facets, for which an exact but expensive distance algorithm is employed.

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Section: Metric Operatorsmentioning

confidence: 99%

Implementing Metric Operators of a Spatial Query Language for 3D Building Models: Octree and B-Rep Approaches

Borrmann

Schraufstetter

Rank

2009

J. Comput. Civ. Eng.

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“…The spaghetti model is a widely discussed model [5,17] and numerous query languages [9,38,21,13] and algebras [19,20] can be found in the literature that are based on a spaghetti-like model.…”

Section: The Spaghetti Modelmentioning

confidence: 99%

Data models and query languages for spatial databases

Paredaens

Kuijpers

1998

Data & Knowledge Engineering

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The main purpose of this paper is to investigate the characteristics that distinguish spatial databases systems from traditional ones. Hereto, we give an overview of some well-known data models and query languages of spatial database systems. We also investigate the concept of genericity, as introduced by Chandra and Harel for classical databases [6], for spatial databases. Paredaens, Van den Bussche and Van Gucht [34] have shown that the concept of genericity breaks up in a hierarchy of genericity classes. In this respect, we classify data models and query languages according to the type of generic operations they are designed to support [33].

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“…They form the basis of a large number of data models and query languages for processing spatial data and have gained access into commercial software products. The literature distinguishes simple spatial data types (for example, Egenhofer 1994, Güting 1988 and complex spatial data types (for example, Clementini & Di Felice 1996a, Schneider 1997, Schneider & Behr 2006, depending on the spatial complexity they are able to model. Simple spatial data types (Figure 1(a)-(c)) only provide simple object structures like single points, continuous lines, and simple regions.…”

Section: Introductionmentioning

confidence: 99%

Soft Computing Techniques in Spatial Databases

Schneider

2010

Soft Computing Applications for Database Technologies

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Spatial database systems and geographical information systems are currently only able to support geographical applications that deal with crisp spatial objects, that is, objects whose extent, shape, and boundary are precisely determined. Examples are land parcels, school districts, and state territories. However, many new, emerging applications are interested in modeling and processing geographic data that are inherently characterized by spatial vagueness or spatial indeterminacy. Examples are air polluted areas, temperature zones, and lakes. These applications require novel concepts due to the lack of adequate approaches and systems. In this chapter, we show how soft computing techniques can provide a solution to this problem. We give an overview of two type systems or algebras that can be integrated into database systems and utilized for the modeling and handling of spatial vagueness. The first type system, called Vague Spatial Algebra (VASA), is based on well known, general, and exact models of crisp spatial data types and introduces vague points, vague lines, and vague regions. This enables an exact definition of the vague spatial data model since we can build it upon an already existing theory of spatial data types. The second type system, called Fuzzy Spatial Algebra (FUSA), leverages fuzzy set theory and fuzzy topology and introduces novel fuzzy spatial data types for fuzzy points, fuzzy lines, and fuzzy regions. This enables an even more fine-grained modeling of spatial objects that do not have sharp boundaries and interiors or whose boundaries and interiors cannot be precisely determined. This chapter provides a formal definition of the structure and semantics of both type systems. Further, we introduce spatial set operations for both algebras and obtain vague and fuzzy versions of geometric intersection, union, and difference. Finally, we describe how these data types can be embedded into extensible databases and show some example queries.

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Geo-relational algebra: A model and query language for geometric database systems

Cited by 114 publications

References 22 publications

Implementing Metric Operators of a Spatial Query Language for 3D Building Models: Octree and B-Rep Approaches

Implementing Metric Operators of a Spatial Query Language for 3D Building Models: Octree and B-Rep Approaches

Data models and query languages for spatial databases

Soft Computing Techniques in Spatial Databases

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