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1999
Spatial databases, addressing the growing data management and analysis needs of spatial applications such as Geographic Information Systems, have been an active area of research for more than two decades. This research has produced a taxonomy of models for space, spatial data types and operators, spatial query languages and processing strategies, as well as spatial indexes and clustering techniques. However, more research is needed to improve support for network and field data, as well as query processing (e.g., cost models, bulk load). Another important need is to apply spatial data management accomplishments to newer applications, such as data warehouses and multimedia information systems. The objective of this paper is to identify recent accomplishments and associated research needs of the near term.
We propose a definition of a spatial database system as a database system that offers spatial data types in its data model and query language and supports spatial data types in its implementation, providing at least spatial indexing and spatial join methods. Spatial database systems offer the underlying database technology for geographic information systems and other applications. We survey data modeling, querying, data structures and algorithms, and system architecture for such systems. The emphasis is on describing known technology in a coherent manner rather than on listing open problems.
Journal of Visual Languages & Computing, 1990
On July 19-22, the National Center for Geographical Information and Analysis held the specialist Meeting of the Research Initiative on Very Large Spatial Databases (VLSDB) at Santa Barbara, CA. At this workshop, 42 participants from the U.S. and Europe discussed research issues related to the design of database management systems for geographic information systems and identified a long-term research agenda germane to the development of the next generation of geographic information systems. This paper summarizes the discussions that took place.
Spatial database is a database that is optimized to store and query data. In order to process spatial database a set of functions are needed to process spatial data types called geometry or feature .This paper presents a framework to adapt SQL queries and provide the best result among the available techniques of spatial query processing. Spatial objects are stored in the spatial database, which are expressed by spatial data and attribute data. Spatial data depicts the information about the location and shape of the spatial data, etc. Attribute data also expresses the non-spatial information about name and special attributes of the spatial object. It is used in spatial database application to optimize the spatial query due to its high volume of the spatial data, complexity of spatial query and spatial objects.
In this paper, we introduce an indexing method for accessing spatial databases. The index structure described here is multi-dimensional and is an extension of Multilevel Grid File (MLGF) combined with the z-ordering technique to efficiently handle indexing on the spatial components of the objects. The other important property of the proposed index structure is to be able to index on fuzzy information and process fuzzy querying in spatial databases. Handling spatial, aspatial data and fuzzy information in the physical database is necessary to satisfy some of the requirements of the spatial database applications, i.e., the geographic information systems (GIS) applications. With our proposed multi-dimensional index structure (we call it ExMLGF in this paper), one can create an index structure on aspatial (and fuzzy) data along with spatial data on the same index structure and process aspatial, spatial queries and fuzzy/crisp queries efficiently for the spatial database applications. The ExMLGF access structure is designed and implemented in a way that database users can have fuzzy queries on both homogenous and heterogeneous domains. In this paper we include a number of algorithms for processing different kinds of queries in spatial databases.
2018
Spatial information processing has been a centre of attention of research in the previous decade. In spatial databases, data related with spatial coordinates and extents are retrieved based on spatial proximity. A large number of spatial indexes have been proposed to make ease of efficient indexing of spatial objects in large databases and spatial data retrieval. The goal of this paper is to review the advance techniques of the access methods. This paper tries to classify the existing multidimensional access methods, according to the types of indexing, and their performance over spatial queries. K-d trees out performs quad tress without requiring additional memory usage.
This chapter is concerned with multidimensional data models for spatial data warehouses. Over the last few years different approaches have been proposed in the literature for modelling multidimensional data with geometric extent. Nevertheless, the deûnition of a comprehensive and formal data model is still a major research issue. The main contributions of the chapter are twofold: First, it draws a picture of the research area; second it introduces a novel spatial multidimensional data model for spatial objects with geometry (MuSD-multigranular spatial data warehouse). MuSD complies with current standards for spatial data modelling, augmented by data warehousing concepts such as spatial fact, spatial dimension and spatial measure. The novelty of the model is the representation of spatial measures at multiple levels of geometric granularity. Besides the representation concepts, the model includes a set of OLAP operators supporting the navigation across dimension and measure levels.
Technologies, Techniques and Trends, 2005
In order to generate efficient execution plans for queries comprising spatial data types and predicates, the database system has to be equipped with appropriate index structures, query processing methods, and optimization rules. Although available extensible indexing frameworks provide a gateway for seamless integration of spatial access methods into the standard process of query optimization and execution, they do not facilitate the actual implementation of the spatial access method itself. An internal enhancement of the database kernel is usually not an option for database developers. The embedding of a custom block-oriented index structure into concurrency control, recovery services and buffer management would cause extensive implementation efforts and maintenance cost, at the risk of weakening the reliability of the entire system. The server stability can be preserved by delegating index operations to an external process, but this approach induces severe performance bottlenecks due to context switches and inter-process communication. Therefore, we present the paradigm of object-relational spatial access methods that perfectly fits to the common relational data model and is highly compatible with the extensible indexing frameworks of existing object-relational database systems allowing the user to define application-specific access methods.
2009
A comparative study is presented on the most known k-nearest neighbor search methods used by spatial-temporal database systems in order to provide the advantages and limitations of each algorithm used in system simulations. The scope is limited to the development of the grid indexing searching technique in terms of three different algorithms, including the well-known CPM, SEA-CNN, and CkNN algorithm. These algorithms don't make any assumptions about the movement of queries or objects. There are a number of functions proposed, which is used in: 1) partitioning the space around the query point in case of CPM and CkNN algorithms and 2) computing minimum and maximum distances between query and cell/level. All studied algorithms are compared together according to the required number of nearest neighbors, grid granularity, location update rate, speed, and population. An accuracy comparison is done between these algorithms to estimate the performance and determine the searching region error during query processing.
2006
This chapter is concerned with multidimensional data models for spatial data warehouses. Over the last few years different approaches have been proposed in the literature for modelling multidimensional data with geometric extent. Nevertheless, the definition of a comprehensive and formal data model is still a major research issue. The main contributions of the chapter are twofold: first, it draws a picture of the research area; second it introduces a novel spatial multidimensional data model for spatial objects with geometry (MuSD-Multigranular Spatial Data warehouse). MuSD complies with current standards for spatial data modelling, augmented by data warehousing concepts such as spatial fact, spatial dimension and spatial measure. The novelty of the model is the representation of spatial measures at multiple levels of geometric granularity. Besides the representation concepts, the model includes a set of OLAP operators supporting the navigation across dimension and measure levels.
A comparative study is presented on the most known k-nearest neighbor search methods used by spatial-temporal database systems in order to provide the advantages and limitations of each algorithm used in system simulations. The scope is limited to the development of the grid indexing searching technique in terms of three different algorithms, including the well-known CPM, SEA-CNN, and CkNN algorithm. These algorithms don't make any assumptions about the movement of queries or objects. There are a number of functions proposed, which is used in: 1) partitioning the space around the query point in case of CPM and CkNN algorithms and 2) computing minimum and maximum distances between query and cell/level. All studied algorithms are compared together according to the required number of nearest neighbors, grid granularity, location update rate, speed, and population. An accuracy comparison is done between these algorithms to estimate the performance and determine the searching region error during query processing.
International Journal of Data Mining & Knowledge Management Process, 2013
With the rapid development in Geographic Information Systems (GISs) and their applications, more and more geographical databases have been developed by different vendors. However, data integration and accessing is still a big problem for the development of GIS applications as no interoperability exists among different spatial databases. In this paper we propose a unified approach for spatial data query. The paper describes a framework for integrating information from repositories containing different vector data sets formats and repositories containing raster datasets. The presented approach converts different vector data formats into a single unified format (File Geo-Database "GDB"). In addition, we employ "metadata" to support a wide range of users' queries to retrieve relevant geographic information from heterogeneous and distributed repositories. Such an employment enhances both query processing and performance.
2012
Spatial data warehouses (SDWs) allow for spatial analysis together with analytical multidimensional queries over huge volumes of data. The challenge is to retrieve data related to ad hoc spatial query windows according to spatial predicates, avoiding the high cost of joining large tables. Therefore, mechanisms to provide efficient query processing over SDWs are essential. In this paper, we propose two efficient indices for SDW: the SB-index and the HSB-index. The proposed indices share the following characteristics. They enable multidimensional queries with spatial predicate for SDW and also support predefined spatial hierarchies. Furthermore, they compute the spatial predicate and transform it into a conventional one, which can be evaluated together with other conventional predicates by accessing a star-join Bitmap index. While the SB-index has a sequential data structure, the HSB-index uses a hierarchical data structure to enable spatial Geoinformatica
Spatial data has become more important everyday in decision-making and planning processes. As such, it needs to be stored and retrieved in information systems that often require high performance due to the voluminous nature of spatial data. Typically this is not much of a problem unless one considers the effect of spatial extent as a function of time in information retrieval. Taxonomies of spatial objects can be useful in suggesting a storage model that addresses spatiotemporal queries. This research develops such a taxonomy and then proposes how the taxonomy might lend itself to a high performance binary tree model for query and storage of spatial data that considers the relationship of time on the shape of objects in storage. The approach has the potential to retrieve data for certain types of queries much more quickly than a linear search of the same types of spatial objects. Comparative evaluation will be the subject of future work.
Transactions in …, 2004
A growing number of services are now being offered over mobile devices. They typically combine positioning technology, wireless technology and spatial analysis methods applied to detailed geographical, time based data to offer services in support of time critical, spatial, mobile decision making. A collection of research issues need to be addressed in the successful delivery of such services that extend beyond issues of sophisticated network algorithms. Specifically, careful attention needs to be given to: (1) people and user environments; (2) access to networks; (3) policy, privacy and liability; (4) standards and interoperability; and (5) data quality. Spatial Data Infrastructure (SDI) is the collective term for these interconnected issues and has been a traditional area of research associated with geographic information science. In this paper the particular SDI requirements for the successful delivery of Location Based Services (LBS) are explored through the development of a prototype LBS for journey planning. The initial implementation and testing of this prototype has revealed that the SDI context is well suited as a framework within which to examine the related LBS issues. From a more technical perspective, the testing has revealed that data structure and the means by which large data sets are mined (in order to gather information to present to users) is critical to the success of timely information delivery over limited bandwidth media.
2005
Spatial database systems has been an active area of research over the past 20 years. A large number of research efforts have appeared in literature aimed at effective modelling of spatial data and efficient processing of spatial queries. This book investigates several aspects of a spatial database system, and includes recent research efforts in this field. More specifically, some of the topics covered are: spatial data modelling; indexing of spatial and spatio-temporal objects; data mining and knowledge discovery in spatial and spatio-temporal databases; management issues; and query processing for moving objects. Therefore, the reader will be able to get in touch with several important issues that the research community is dealing with. Moreover, each chapter is self-contained, and it is easy for the non-specialist to grasp the main issues. xiv A Closing Remark The authors have made significant efforts to provide high-quality chapters, despite space restrictions. These authors are well-known researchers in the area of spatial and spatio-temporal databases, and they have offered significant contributions to the literature. We hope that the reader will gain the most out of this effort.
Pressure on land development in urban areas causes progressive efforts in spatial planning and management. The physical growth expansion of urban areas to accommodate rural migration gives a massive impact to social, economic and politics of major cities. Most of the models used in managing urban areas are moving towards sustainable urban development which to fulfill current necessities while preserving the resources for future generation. However in order to manage large amounts of urban spatial data, an efficient spatial data constellation method is needed. With the ease of three dimensional (3D) spatial data usage in urban areas as a new source of data input, practical spatial data indexing is necessary to improve data retrieval and management. Current two dimensional (2D) spatial indexing approaches seem not applicable to the current and future spatial developments. Therefore, the objective of this paper is to review existing spatial data indexing approaches to managing large urban area datasets. Each approach will be reviewed and discussed according to the current spatial data scenarios. In addition, a 3D spatial data indexing method will be discussed as an alternative for organizing 3D spatial data.
2001
Emerging database applications require the use of new indexing structures beyond B-trees and R-trees. Examples are the k-D tree, the trie, the quadtree, and their variants. They are often proposed as supporting structures in data mining, GIS, and CAD/CAM applications. A common feature of all these indexes is that they recursively divide the space into partitions. A new extensible index structure, termed SP-GiST, is presented that supports this class of data structures, mainly the class of space partitioning unbalanced trees. Simple method implementations are provided that demonstrate how SP-GiST can behave as a k-D tree, a trie, a quadtree, or any of their variants. Issues related to clustering tree nodes into pages as well as concurrency control for SP-GiST are addressed. A dynamic minimum-height clustering technique is applied to minimize disk accesses and to make using such trees in database systems possible and efficient. A prototype implementation of SP-GiST is presented as well as performance studies of the various SP-GiST's tuning parameters.
Abstract: The increased availability of spatial data in recent years has lead to new challenges in the analysis of large multidimensional datasets. One solution is to integrate GIS with OLAP and relational databases. Another strategy has been to leverage existing spatial capabilities of databases to perform spatial OLAP. In this article, we review existing modelling strategies for spatial data warehousing at all three levels: conceptual, logical and implementation.
Data & Knowledge Engineering, 1998
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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