Gting R. H.: An Introduction to Spatial Database Systems. VLDB Journal , 3(4): 357-399, 1994.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....for representing entities with large areas such as administrative units or parcels. There is no common agreement on the set of operations which must be provided in a spatial ADT based model, except perhaps for topological relationships [6] The models vary depending on the targeted application [20, 21, 39, 22]. The ADT approach has been adopted in some relational DBMS, including ORACLE [42] or Postgres [32] For concreteness, Table 1 shows the main types in the Postgres system (without the associated operations) Geometric Type Representation Description point (x; y) Point in space line ( x 1 ; y 1 ....

R.H. Gting. An Introduction to Spatial Database Systems. The VLDB Journal, 3(4):357--399, 1994.

....to make spatial relations explicit. This function is partially supported by the spatial database (SDB) which offers spatial data types in its data model and query language and supports them in its implementation, providing at least spatial indexing and efficient algorithms for spatial join [13]. Thus spatial databases supply an adequate representation of both single objects and spatially related collections of objects. In particular, the abstraction primitives for spatial objects are point, line and region. Among the operations defined on spatial objects, spatial relationships are the ....

Gting, R. H., `An introduction to spatial database systems', VLDB Journal, Vol. 3, No 4, 1994, pp. 357--399.

....of selections are expected to maintain their initial distribution, since there is no explicit dependency between the query attributes. Thus the cost of the join can be estimated using the selectivity of the selections and statistical information about the base tables. In spatial database systems [9], a complex query may contain several spatial and non spatial components. For instance, the query find all cities within 400km of Munich, which are less than 10km away from a forest and are crossed by a river wider than 20m includes two spatial joins (City Forest, City River) a non spatial ....

....formulae that estimate the selectivity of complex spatial queries. In Section 4 we evaluate the accuracy of the proposed models for complex spatial queries on uniform data. Section 5 discusses extensions to real data and Section 6 concludes the paper. 2. Background Spatial database systems [9] organize and manage large collections of multidimensional data. Spatial relations, apart from conventional attributes, contain one attribute that captures the geometric features of the stored objects. For example, the last attribute in relation City(CName, PostalCode, Population, CRegion) is of ....

Gting R.H. An Introduction to Spatial Database Systems, VLDB Journal, 3(4): 357-399, 1994.

....are expected to maintain the same distribution as before, since there is no explicit dependency between the query attributes. Thus the cost of the plan can be estimated using the selectivity of the selections and statistical information about the base tables. In spatial database systems [Gt94] a complex query may comprise several spatial and non spatial components. For instance, the query find all cities within 400km of Munich, which are crossed by a river wider than 20m and are within distance 10km from a forest includes two spatial joins (City River, City Forest) a non spatial ....

Gting R.H. An Introduction to Spatial Database Systems, VLDB Journal, 3(4): 357-399, 1994. 16

....E mail: dimitris cs.ust.hk The Hong Kong University of Science Technology Technical Report Series Department of Computer Science Multiway Spatial Joins Nikos Mamoulis and Dimitris Papadias Technical Report HKUST CS00 01 January, 2000 2 1. INTRODUCTION Spatial database systems [G94] manage large collections of multidimensional data which, apart from conventional features, include special characteristics such as position and spatial extent. The fact that there is no total ordering of objects in space that preserves spatial proximity [G93b] renders conventional indexes, such ....

Gting, R.H. An Introduction to Spatial Database Systems. VLDB Journal, 3(4): 357-399, 1994.

....is about 30 with our fast BOPS method, and even better (about 10 ) if we use the slower, quadratic method. 2 1 INTRODUCTION Multi dimensional and spatial database management systems (DBMS) have attracted a lot of interest. One of the most important operations in a spatial DBMS [GT 94] is the spatial join, which is the counterpart to the equi join in a relational DBMS. The typical query is also called the all pairs query or spatial distance join , as in the example, Estimate the number of schools that are within 5 miles from libraries . Spatial distance joins are ....

R. H. Gting - "An Introduction to Spatial Database Systems". The VLDB Journal. 3(4). October 1994. pp. 357-399.

....on ADT extensions. Thus, experiences and approaches achieved by the database research community should be of both practical importance and interest in developing such systems. Especially, spatial and temporal database research have adopted different principles in query language design, e.g. see [9, 17] and [4, 14, 19] respectively. The principle differences are shown by the fact that a temporal query language typically redefines their underlying algebra to become temporal, and, thereby, make dimension semantics an intrinsic property of the algebra, and the fact that a spatial query language ....

....b WHERE CONTAINS(e.region, b.location) The spatial semantics implied by the above query is specified by the user. For example, the spatial join is formulated as an old style join (e.g. cf. 15] followed by a selection criteria based on a user specified spatial predicate. According to Gting [9]: Strictly speaking, there is no such thing as a spatial selection. and, furthermore, Similar to a spatial selection, a spatial join is a join that compares any two objects with a predicate according to their spatial attributes meaning that the spatial predicate is user specified. ....

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R. H. Gting. An Introduction to Spatial Database Systems. The VLDB Journal, 3:357--399, 1994.

....and compare their expressiveness. Spatio temporal objects turn out to be specific instances of temporal objects. 1 Introduction In the past, in spite of many similarities, research in spatial and temporal data models and databases has largely developed independently. Spatial database research [G94] has focused on modeling, querying, and integrating geometric and topological information in databases. For the modeling of spatial objects the well known concept of spatial data types (e.g. SV89, SH91, GS95, Sc97] has proved very useful. These have been identified as appropriate and efficient ....

R.H. Gting. An Introduction to Spatial Database Systems. VLDB Journal, vol. 3, no. 4, pp. 357-399, 1994.

....compare their expressive power. Spatio temporal objects turn out to be specific instances of temporal objects. 1 Introduction In the past, in spite of many similarities, research in spatial and temporal data models and databases has largely developed independently. Spatial database research [G94] has focused on modeling, querying, and integrating geometric and topological information in databases. Temporal database research [TCG 93] has concentrated on modeling, querying, and recording the temporal evolution of facts under different notions of time (valid time, transaction time) and ....

R.H. Gting. An Introduction to Spatial Database Systems. VLDB Journal, vol. 3, no. 4, pp. 357-399, 1994.

....no. ERB FMRX CT96 0056. 1 1 Introduction In the past, research in spatial and temporal data models and database systems has mostly been done independently. Spatial database research has focused on supporting the modeling and querying of geometries associated with objects in a database [G94]. Temporal databases have focused on extending the knowledge kept in a database about the current state of the real world to include the past, in the two senses of the past of the real world (valid time) and the past states of the database (transaction time) TCG 93] Nevertheless, many people ....

....handling of attribute values with a representation of widely varying size. These data structures should be kept in a tuple object representation if they are small, and in a separate page sequence, if they are large. Such techniques have already been used in spatial DBMS for spatial data types (see [G94]) For example, the DBMS can offer an extensible array abstraction for the implementation of data types. The structure of polyhedral faces mentioned above can then be mapped into a few arrays of appropriate sizes; persistent pointers between them are given by array indices. Clearly, it is beyond ....

Gting, R.H., An Introduction to Spatial Database Systems. VLDB Journal 4 (1994), 357-399.

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Gting R. H.: An Introduction to Spatial Database Systems. VLDB Journal , 3(4): 357-399, 1994.

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Gting R. H.: An Introduction to Spatial Database Systems. VLDB Journal , 3(4): 357-399, 1994.

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Gting, R.H., 1994. "An Introduction to Spatial Database Systems". VLDB Journal, vol. 3, no.4, October 1994.

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R. H. Gting - "An Introduction to Spatial Database Systems". The VLDB Journal. 3(4). October 1994. pp. 357-399.

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Gting, R. H.. An introduction to spatial database systems. In VLDB Journal, 3(4):357-400, October 1994.

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Gting, R. H. (1994): An introduction to spatial database systems. VLDB Journal 3 (4): 357-399.

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