Egenhofer MJ (1994) Spatial SQL: a query and presentation language. IEEE Transactions on knowledge and data engineering, 6(1):86--95  Home/Search   Document Not in Database   Summary   Related Articles   Check

....spatial databases, whereas GeoMiner includes the spatial data cube construction module, spatial on line analytical processing (OLAF) module, and spatial data mining modules. A spatial data mining language, GMQk (GeoMining Query Language) is designed and implemented as an extension to Spatial SQL [3], for spatial data mining. Moreover, an interactive, user friendly data mining interface is constructed and tools are implemented for visualization of discovered spatial knowledge. 1 Introduction With the rapid progress of research into data mining and data warehousing in recent years [5] many ....

....objects in large databases. Unfortunately, there have not been many spatial data mining systems reported in previous studies. Recent advances in the research on spatial data structures and spatial databases enable the creation of large spatial databases which can be queried in an effective way [3, 6]. These advances in combination with the researches into spa tial reasoning [3] and the advances in data mining in rela, tional databases [5] promote the research into spatial data mining [4, 10, 11, 12, 13, 14] The GeoMiner research group in our Database Systems Research Laboratory has been ....

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M. Egenhofer. Spatial SQL: A query and presentation lan- guage. IEEE Transactions on Knowledge and Data Engineering, 6:86-95, 1994.

....information or spatial information, rather than both. For instance in the temporal domain, interval based time models [17] were followed by TSQL2 s implicit time model [21] and pointbased time models [22, 23] SQL extensions to express spatial queries were proposed by several authors, including [8] and [9] In a seminal paper, Worboys [25] defines a spatio temporal object as a unified object which has both spatial and temporal extents, and is represented by attaching a temporal element to the components of a collection of non overlapping spatial objects that include points, straight line ....

M.J. Egenhofer. Spatial SQL: A Query and Presentation Language. In IEEE Transactions on Knowledge and Data Engineering Vol.6. No.1. pp.86-95, 1994

....west, north, and center, et al.) In this article, we mainly discuss the spatial queries which are dealing with topological and metric relationships. 2. The requests of spatial queries to query languages The advancing direction of spatial query is to develop powerful spatial query language [2 7] . Traditional database qury languages, such as Structyred Query Language (SQL) 8] Quel [1] and QBE (Query By Example) 10] are not adapted to processing spatial data, because they do not consider spatial attributes. Some structured query languages with particular extentions have ....

....data [5,6] As to spatial query languages, it is most important to provide supports for these three categories of queries mentioned in previous section. After investigations of conventional database query languages, we think that spatial query languages should satisfy following reqirements [2] : 1) Supporting abstract data types describing spatial attributes, spatial relationships and operations, so users can process spatial data on a level independent of internal coding, such as x, y coordinates. 2) Query results can be displayed in graph, which is the most natural format of ....

Egenhofer,M.J., Spatial SQL: A Query and Presentation Language. IEEE Trans. on Knowledge and Data Engineering, 1994, Vol.6, No.1, pp.86-95.

....the proposed presentation language is given is section 4. Finally, the use of this presentation language within the SPRING environment is presented in section 5. 2. REQUIREMENTS FOR PRESENTATION LANGUAGES A discussion on the specific requirements for presentation languages for GIS is found in [Ege90, Ege94]. Egenhofer suggests that a spatial query should consist of three parts: a) the description of the set of objects to be retrieved. b) a set of display queries, which separate query results into more detailed sets, each to be displayed in an individual format. c) a display description specifying ....

....a display description specifying how to render the data. Egenhofer also argues that, while the requirement (a) might be fulfilled by a query language which is an extension of existing environments such as SQL, requirements (b) and (c) need a separate presentation language, which should cater for [Ege94]: Assignment of graphical and pictorial descriptors to the geographical objects: association of legends and visual definitions (colour, symbols) to the geographical objects. Presentation control: use of different graphical descriptors (colour, text, legend, scale) to differentiate the query ....

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Egenhofer, M. Spatial SQL: A Query and Presentation Language. IEEE Transactions on Knowledge and Data Engineering, 6:86-95, 1994.

....the semantics of GIS operations. In current practice, the use of different models for fields and features usually leads to implementation of different subsystems on a GIS: raster map operations implementing Tomlin s Map Algebra [11] and vector spatial queries with languages similar to Spatial SQL [12]. This situation is not always desirable. For example, overlap is a well known concept for denoting a topological configuration between two geographical entities [13] In many GIS, it is possible to inquire if two entities represented by vector polygons overlap , but it is not straightforward ....

M. Egenhofer. Spatial SQL: A Query and Presentation Language. IEEE Transactions on Knowledge and Data Engineering, 6:86-95, 1994.

....non specialist users can interpret queries more accurately and more quickly given visual, rather than textual, representations. Experimental design The three null hypotheses for the work reported here were that there would be no difference between the visual (C SPRL) and textual (Spatial SQL [3]) conditions in (1) accuracy of interpretation of queries, 2) number of query interpretations attempted within the time allowed, and (3) subjective preference ratings. The independent variable was the type of query representation, with two conditions: textual and visual. A within subjects design ....

# Egenhofer, M. J. (1994). "Spatial SQL: A Query and Presentation Language". IEEE Transactions on Knowledge and Data Engineering, Vol. 6, No. 1, (p. 86-95).

....implementing Tomlin s Map Algebra (Tomlin, 1990) and vector spatial queries with languages similar to Spatial SQL (Engenhofer, 1994) This situation is not always desirable. For example, overlap is a well known concept for denoting a topological configuration between two geographical entitities (Egenhofer et al. 1994). In many GIS, it is possible to inquire if two entitities represented by vector polygons overlap , but it is not straightforward to inquire if the same property holds for two digital terrain models. 5.1 Atomic Operations on Geographical Objects A general GIS should have basic operations which ....

Egenhofer, M. Spatial SQL: A Query and Presentation Language. IEEE Transactions on Knowledge and Data Engineering, 6:86-95, 1994.

....area and therefore the body of related work only just begins to grow. There has been substantial research on query languages for images and spatial objects, and a survey can be found in [8, 9] Of these query languages, many are based upon extension of SQL, such as PSQL [19] and Spatial SQL [11]. Next come video query languages where the focus is shifted to temporal constraints [1] and content based retrieval [4] Recent efforts begin to address query languages involving images, video, audio and text. Vazirgiannis describes a multimedia database system for multimedia objects that may ....

Egenhofer, M., "Spatial SQL: A Query and Presentation Language", IEEE Transactions on Knowledge and Data Engineering, Vol. 5, No. 2, 1991, pp. 161-174.

....be reconstructed. Observations such as these have led to an abstract data type view of spatial entities with suitable operations, used as attribute types in relational or other systems. Spatial types and operations have been used in many proposals for spatial query languages, e.g. Gut88, SH91, Ege94] and they have been implemented in prototype systems, e.g. OM88, RFS88, Gut89] Dedicated designs of spatial algebras with formal semantics are given in [SV89, GNT91, GS95] Perhaps in part because of the pervasiveness of time and their simpler structures, time types are already supported by ....

M. Egenhofer. Spatial SQL: A Query and Presentation Language. IEEE Transactions on Knowledge and Data Engineering, 6:86--95, 1994.

....the ability to do real time animation is limited. To make the animation of spatiotemporal objects more efficient, we propose to use a separate data model just for the display purposes (the decoupling of retrieval and display was postulated in the context of spatial query languages by Egenhofer [8, 9]) For linear constraint databases, this model is a natural generalization of the spaghetti data model [18] called the parametric spaghetti data model (introduced in [5] The basic modelling construct of the latter model is a parametric polygon. Using parametric polygons the conversion from an ....

M. Egenhofer. Spatial SQL: A Query and Presentation Language. IEEE Transactions on Knowledge and Data Engineering, 6(1), 1994.

....representations and data models, multidimensional access methods, as well as spatio temporal query languages and their optimization. 1. 2 Current developments In recent years, spatial database research has been mainly involved with the development of spatial data models [AS90] BM92] Ege94] and ecient spatial access methods [GG96] Focus is now being placed on the ecient implementation of complex spatial operations [BKSS94] Gun93] LR96] Joi96] Diculties arise because, in contrast with relational databases, there is neither a standard spatial algebra nor a standard spatial query ....

Max J. Egenhofer . Spatial SQL: A query and presentation language. tkde, 6(1):86-95, February 1994.

....graphics, images, audio, video, and animation. Many applications depend on spatial relationships among multimedia data. There is significant research on spatial relationships in image databases and geographic information systems (GIS) OM88, RFS88, Ege91, CIT 93, AEG94, CSE94, PS94, SYH94, Ege94, NSN95, PTSE95] On the other hand, very little research has been done on spatial modeling in the context of video data. Most work on videos [LG91, Mas91, OT93, LG93, WDG94, SW94, GBT94, HR95, LG OS96] is concentrated on temporal relationships which are certainly the most striking characteristic ....

....of intersection (A 0 B 0 ; A 0 B; A B 0 ; A B) between interiors and boundaries define a set of topological relations. These four intersections result in eight topological relations: disjoint, contains, inside, meet, equal, covers, covered by, and overlap. A spatial SQL [Ege94] based on this topological representation is proposed. The spatial SQL supports direct spatial search, hybrid spatial search, complex spatial search, and direct spatial computation. Papadias et al. PS94, PTSE95, GPP95] assume a construction process that detects a set of special points in an ....

M. Egenhofer. Spatial SQL: A query and presentation language. IEEE Transactions on Knowledge and Data Engineering, 6(1):86---95, January 1994.

....on the given application domain, although some operators (such as intersection) are generally more common than others. Queries are often expressed by some extension of SQL that allows abstract data types to represent spatial objects and their associated operators (Roussopoulos and Leifker 1984; Egenhofer 1994). The result of a query is usually a set of spatial data objects. In the remainder of this section, we give a formal definition of several of the more common spatial database operators. Figures 3 through 8 give some concrete examples. Query 1 (Exact Match Query EMQ, Object Query) Given an object ....

Egenhofer, M. (1994). Spatial SQL: A query and presentation language. IEEE Trans. Knowledge and Data Eng. 6 (1).

....work was partially supported by the CHOROCHRONOS project, funded by the EU under the Training and Mobility of Resarchers Programme, Contract No. ERB FMRX CT96 0056. 1 Within this eoeort, of fundamental importance has been the development of generic spatial algebras, as for example [G#t88, SH91, Ege94, GS95] Such algebras pursue two basic goals. On the one hand, they provide a set of spatial data types able to suitably and eOEciently represent the kind of spatial data managed in a wide set of application environments. On the other hand, they ooeer a suitable set of operations over these types ....

M. Egenhofer. Spatial SQL: A Query and Presentation Language. IEEE Transactions on Knowledge and Data Engineering, 6(1):8695, 1994.

....Introduction Temporal and spatial constraint networks do not live alone in the wilderness. In many cases they are components of larger systems e.g. temporal database systems (Koubarakis 1997b; Brusoni et al. 1995; Dean McDermott 1987; Schrag, Boddy, Carciofini 1992) spatial database systems (Egenhofer 1994; Papadias et al. 1995) knowledge representation systems (Mylopoulos et al. 1990) natural language systems (Miller Schubert 1988) planning systems (Penberthy Weld 1994) scheduling systems (Cheng Smith 1994) multimedia systems (Subrahmanian 1998) and so on. We believe that temporal and ....

Egenhofer, M. 1994. Spatial SQL: A Query and Presentation Language. IEEE Transactions on Knowledge and Data Engineering 6:86--95.

....overlay, image transforms) Type construction and multi level algebra, other operations (area, volume, boundary, rotation, translation, etc. 4. Querying: Why not SQL, selecting spatial objects, map algebra, raster algebra; specifying display forms and rendering of spatial attributes[6]; cartographical map scale, projections and generalization; geographical user interfaces and legends; Query languages such as GeoSQL, GRASS etc. 5. Spatial Indexing: clustering, mapping to one dimensional index, space filling curves (Hilbert, Z order) multidimensional data structures for points ....

M. J. Egenhofer, Spatial SQL: A Query and Presentation Language, Trans. on Know. and Data Eng. 6(1)IEEE, (Feb. 1994).

....be reconstructed. Observations such as these have led to an abstract data type view of spatial entities with suitable operations, used as attribute types in relational or other systems. Spatial types and operations have been used in many proposals for spatial query languages, e.g. Guting 1988; Egenhofer 1994]; and they have been implemented in prototype systems, e.g. Roussopoulos et al. 1988; Guting 1989] Dedicated designs 34 Delta R. H. Guting at al. of spatial algebras with formal semantics are given in [Scholl and Voisard 1989; Gargano et al. 1991; Guting and Schneider 1995] Perhaps in part ....

Egenhofer, M. 1994. Spatial SQL: A Query and Presentation Language. IEEE Transactions on Knowledge and Data Engineering 6, 86--95.

....must be reconstructed. Observations such as these have led to an abstract data type view of spatial entities with suitable operations, used as attribute types in relational or other systems. Spatial types and operations have been used in many proposals for spatial query languages, e.g. Gut88, Ege94] and they have been implemented in prototype systems, e.g. RFS88, Gut89] Dedicated designs of spatial algebras with formal semantics are given in [SV89, GNT91, GS95] Perhaps in part because of the pervasiveness of time and their simpler structures, time types are already supported by ....

M. Egenhofer. Spatial SQL: A Query and Presentation Language. IEEE Transactions on Knowledge and Data Engineering, 6:86--95, 1994. 34

....Figure 3, which illustrates this spatial data type hierarchy consists of Point, Curve and Polygon classes and a parallel class of Geometry Collection. The basic operations operative on all datatypes are shown in Table 1. The topological operations are based on the ubiquitous 9 intersection model [10]. Using the OGIS specification, common spatial queries can be intutively posed in SQL. For example, the query Find all lakes which have an area greater than 5 sq. km. and are within 20 km. from the campgrounds can be posed as shown in Figure 2(a) Area(L.Geometry) 5 L.name, Fa.name s s ....

M. Egenhofer. Spatial SQL: A Query and Presentation Language. IEEE Transactions on Knowledge and Data Engineering, 6(1):86--95, 1994.

....have brought much attention to researchers recently. In this paper, we describe a new query language as well as a new design to the graphical user interface (GUI) tailored for geographic information systems (GIS) The material presented here is based on the papers written by Egenhofer [1] and by Voisard [2] Key Words. Spatial SQL, Geographic Information Systems, Geographic Database User Interfaces. 1 Introduction Developing query languages and graphical tools for content based retrieval have brought much attention to researchers recently. In this paper, we describe a new query ....

....retrieval have brought much attention to researchers recently. In this paper, we describe a new query language as well as a new design to the graphical user interface (GUI) tailored for geographic information systems (GIS) The material presented here is based on the papers written by Egenhofer [1] and by Voisard [2] The outline of the paper is as follows. In x2, we present a new query and presentation language, the Spatial SQL, as an extension to the existing query language SQL. In x3, the concept of mapget will be introduced as the basis of designing the GUI to be integrated with the ....

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J. Egenhofer, Spatial SQL: A Query and Presentation Language, IEEE transactions on Knowledge and Data Engineering, Vol 6, No. 1, pp 86--95, February 1994.

.... make reference to topological properties of regions (e.g. in the ARC INFO system [Mor85, Mor89] Among them, the 4 intersection model of topological relationships [FK86, Her91, Wor92] has been widely adopted in geographic information systems and has been used in several spatial query languages [Ege94, OV91, SZ91]. The satisfiability problem for 4 intersection relationships is investigated in [GPP95] The expressiveness of these relationships has been investigated by Egenhofer and Franzosa [EF91] who make the argument that they are natural and cognitively plausible, and observe that they cover all ....

M. Egenhofer. Spatial SQL: A Query and Presentation Language. IEEE Transactions on Knowledge and Data Engineering, 6(1):86-95, 1994.

....of predicates for each combination of spatial data types. For example, for two regions the eight predicates disjoint, meet, overlap, coveredBy, covers, inside, contains, and equal have been identified. A spatial query language based on these predicates and called Spatial SQL has been proposed in [7]. 1.3 Spatio Temporal Predicates From an application point of view, we have found that expressing and querying temporal changes or developments of spatial objects is an important feature of a spatiotemporal query language. For this purpose spatio temporal predicates are needed which model these ....

M. J. Egenhofer. Spatial SQL: A Query and Presentation Language. IEEE Transactions on Knowledge and Data Engineering, 6(1):86--95, 1994.

....information visualization techniques for information retrieval. These systems however do not deal with special purpose data types such as spatial and temporal data. Most existing spatial query languages are textual (SQL based) requiring users to refer to geometric data using textual queries [Ege94] CW96] The Oracle8 Spatial Cartridge [Ora] SpatialWare [Map] and Spatial SQL [Ege94] use a text based query language for spatial data. The disadvantage of these SQL type languages is that users often think of spatial relationships in terms of images depicting the actual spatial positions, and ....

....do not deal with special purpose data types such as spatial and temporal data. Most existing spatial query languages are textual (SQL based) requiring users to refer to geometric data using textual queries [Ege94] CW96] The Oracle8 Spatial Cartridge [Ora] SpatialWare [Map] and Spatial SQL [Ege94] use a text based query language for spatial data. The disadvantage of these SQL type languages is that users often think of spatial relationships in terms of images depicting the actual spatial positions, and the SQL type languages require the translation of this into a non spatial language. ....

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M. Egenhofer. Spatial SQL: A query and presentation language. IEEE Trans. on Knowledge and Data Eng., 6:86--95, Feb 1994.

....been argued in (Zloof, 1977) that Query By Example is easier to learn by novice users than conventional languages such as SQL and QUEL. Similarly we believe that PQBE is easier to learn and use than other query languages that deal with space, such as extensions of SQL (Roussopoulos et al. 1987) (Egenhofer, 1994), as well as verbal QBE, because of its close correspondence with the structure of space. For the following examples we will consider that our database consists of the symbolic spatial indexes of Figure 7.1; such indexes could correspond to visual scenes, geographic maps or other forms of spatial ....

Egenhofer, M. (1994) Spatial SQL: A Query and Presentation Language. IEEE Transactions on Knowledge and Data Engineering, Vol 6, no 1, pp. 86-95.

....relations. We also investigate queries that involve complex spatial conditions in the form of disjunctions and conjunctions and we discuss possible extensions. 1. INTRODUCTION The representation and processing of spatial relations has recently gained much attention in Spatial Query Languages (Egenhofer, 1994, Papadias and Sellis, 1994b) Image and Multimedia Databases (Papadias et al. 1994a, Sistla et al. 1994) Geographic Applications (Frank, 1994) Spatial Reasoning (Glasgow, 1994) and Cognitive Science (Glasgow and Papadias, 1992) Several kinds of spatial relations have been defined and used. ....

....logic. Related work can be found also in (Vieu, 1993) Tests with human subjects have shown evidence that the 9 intersection model has potential for defining cognitively meaningful spatial predicates, a fact that renders the above relations a good candidate for commercial systems (Mark and Egenhofer, 1994). In fact, the 9 intersection model has been implemented in Geographical Information Systems (GIS) Hadzilacos and Tryfona (1992) for instance, used it to express geographical constraints, and Mark and Xia (1994) to determine spatial relations in ARC INFO. In addition there are implementations in ....

Egenhofer, M. (1994) Spatial SQL: A Query and Presentation Language. IEEE Transactions on Knowledge and Data Engineering, Vol 6(1), pp. 161-174.

....on the given application domain, although some operators (such as intersection) are generally more common than others. Queries are often expressed by some extension of SQL that allows abstract data types to represent spatial objects and their associated operators (Roussopoulos and Leifker 1984; Egenhofer 1994). The result of a query is usually a set of spatial data objects. In the sequel, we give a formal definition of several of the more common spatial database operators. Query 1 (Exact Match Query EMQ, Object Query) Given an object o 0 with geometry o 0 :G E d , find all objects o with the ....

Egenhofer, M. (1994). Spatial SQL: A query and presentation language. IEEE Trans.

....functionality available in the GUI. In Section 4, a sample session is given to illustrate how a user interacts with our system. Finally, a summary is given in Section 5. 2 Previous Work Various systems have been built to investigate different issues in spatial data management. See for instance, [1, 4, 5, 7, 11]. The QL G project concentrates on data modeling, design and efficient implementation of spatial operators, spatial indexing mechanism, as well as GUI for data entry, retrieval and visualization of spatial query results. We shall first give a brief survey of several recent prototypes that ....

....on the 2 D map) and by explicitly composing ad hoc queries in Paradise s extended SQL syntax. Objects can be browsed from an extent and displayed as text strings. Also, objects to be updated can be selected either by pointing and clicking or via the textual browser. 2.1. 3 Spatial SQL Spatial SQL [5] consists of two components: a spatial data retrieval query language and a Graphical Presentation Language (GPL) Users retrieve spatial data with an SQL look alike query. The presentation or display of the query results is specified with constructs in GPL. Central to GPL is the concept of the ....

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Egenhofer, M.J., "Spatial SQL: A Query and Presentation Language," IEEE Transaction on Knowledge and Data Engineering, 1994, Volume 6, No 1, pp. 86-95.

....rooms, price, distance from a fixed point, etc) However, it does not allow the user to specify the relative spatial position of two objects. Our goal is to provide a new class of dynamic filters tuned for continuous spatial querying. Most existing spatial query languages are textual (SQL based) Ege94] The possibly most popular GIS system, MapInfo uses an SQL style language to specify queries to query primarily over non spatial and a few spatial attributes such as area and distance of the underlying data. This language however is neither incremental nor direct manipulation based and thus ....

M. Egenhofer. Spatial SQL: A query and presentation language. IEEE Trans on Knowledge and Data Engg, 6:86--95, Feb 1994.

....to reality. Also the technique of recursive holes has some unexpected applications, such as the representation of a third dimension in a two dimensional space (like isobars and isotherms) Figure 2 The Spaghetti Model is a widely discussed model [Bur77,Gue88] and numerous query languages [Cha94, Rig94,Gut94a,Ege94b] and algebras [Gut88,Gut89] can be found in the literature that are based on a spaghetti like model. 1.3 The Peano Model In contrast to the Spaghetti Model, some models try intentionally to represent every point of an object, in the same sense as the Raster Model. Such models are sometimes called ....

....(0,0) translate the the objects of the relation 5 in the direction of the x axis; rotate the objects of the relation 90 degrees around (0,0) give the gravity center of each object. Max Egenhofer has studied the topological issues that are related with geomatic data types very extensively [Ege88,Ege89,Ege91,Ege93,Ege94a,Ege94b]. In [Ege91,Ege93] the 9 intersection model is given for topological relations in IR 2 . This model is based on the overlapping properties of the interior (A ,B ) the complement (A,B) and the boundary (dA,dB) of two two dimensional objects A and B. There are 3 x 3 = 9 combinations for the ....

Egenhofer M., Spatial SQL: a Query and Presentation Language, IEEE Transactions on Knowledge and Data Engineering, Vol. 6, No.1, 1994.

....querying mechanism and a graphical display of results. We borrow their ideas of sliders and coupling of interfaces for feedback but add new features for spatial data types. Most of the existing spatial query languages are SQL based, requiring users to refer to geometric data using textual queries [Ege94] CW96] Some of them map complex spatial data into the (simple) relational model, then requiring the users to understand the implementation details of spatial data. GEO QUEL [BS77] and Query by Pictorial Example [CF80] are examples of query languages where an image depicting the relationship is ....

....model, then requiring the users to understand the implementation details of spatial data. GEO QUEL [BS77] and Query by Pictorial Example [CF80] are examples of query languages where an image depicting the relationship is drawn as a query to the system. The disadvantage of SQL type languages [Ege94] is that, users often think of spatial relationships in terms of images depicting the actual spatial positions, and the SQL type languages require the translation of this into a non spatial language. Egenhofer proposed Spatial SQL [Ege94] which incorporates spatial operations and relationships ....

[Article contains additional citation context not shown here]

M. Egenhofer. Spatial SQL: A query and presentation language. IEEE Transactions on Knowledge and Data Engineering, 6:86--95, February 1994.

....central role. In recent years, there have probably been two principal approaches to the development of spatial database systems: Kernel extensions to relational databases: Systems in this category extend the relational model and an associated query language with spatial data handling facilities [6, 11, 15]. As relational database languages are not powerful enough to be used to implement core spatial data types, spatial extensions are generally implemented by extending the kernel of the database or by exploiting abstract data type facilities. The advantages of these systems are that they provide ....

Max J. Egenhofer. Spatial SQL: A query and presentation language. IEEE Trans. Knowledge and Data Eng., 6:86--95, 1994.

....ffl translate the the objects of the relation 5 in the direction of the x axis; ffl rotate the objects of the relation 90 degrees around (0; 0) ffl give the gravity center of each object. Max Egenhofer has studied the topological issues that are related with geomatic data types very extensively [14, 10, 11, 12, 15, 13]. In [11, 12] the 9 intersection model is given for topological relations in R 2 . This model is based on the overlapping properties of the interiors (A ffi ; B ffi ) the complements (A; B) and the boundaries ( A; B) of two two dimensional objects A and B. Although this model only ....

....approximation to reality. Also the technique of recursive holes has some unexpected applications, such as the representation of a third dimension in a two dimensional space (like isobars and isotherms) 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. 3.3.3 The Peano Model In contrast to the spaghetti model, some models try intentionally to represent every point of an object, in the same sense as the raster model. Such models are sometimes called ....

M. Egenhofer. Spatial SQL: a query and presentation language. IEEE Transactions on Knowledge and Data Engineering, 1994.

....number of rooms, price, distance from a fixed point, etc) However, it does not allow the user to specify the relative spatial position of two objects. Our goal is to provide a new class of dynamic filters tuned for continuous spatial querying. Most spatial query languages are textual (SQL based) [3]. The possibly most popular GIS system MapInfo 1 uses an SQL style language to specify queries to query primarily over non spatial and a few spatial attributes such as area and distance of the underlying data. This language however is neither incremental nor direct manipulation based and thus ....

M. Egenhofer. Spatial SQL: A query and presentation language. IEEE Trans. on Knowledge and Data Eng., 6:86--95, Feb 1994.

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M. Egenhofer, Spatial SQL: A Query and Presentation Language, IEEE Transactions on Knowledge and Data Engineering, vol. 6, no. 1, pp. 86-95, 1994.

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M. Egenhofer, Spatial SQL: A Query and Presentation Language, IEEE Transactions on Knowledge and Data Engineering, vol. 6, no. 1, pp. 86-95, 1994.

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Egenhofer, M.: Spatial SQL: A Query and Presentation Language. IEEE Transactions on Knowledge and Data Engineering. 6:(1) (1994) 86-95.

....Spatio Temporal Object Model and Query Language Bo Huang, Michael F. Worboys, Chris Johnson, John Stell and Keith Mason Department of Computer Science Keele University Keele, Staffs, UK ST5 5BG E mail: bohuang cs.keele.ac. uk Spatial databases (see, e.g. Egenhofer, 1994) and temporal databases (see, e.g. Snodgrass, 1995) have mostly been studied on parallel, but clearly separate tracks. As geophenomena are associated with both space and time, there has been a growing interest in the integration of spatial and temporal components, leading to the study of ....

Egenhofer, M., 1994, Spatial SQL: a query and presentation language. IEEE Transactions on Knowledge Engineering and Data Engineering, 6(1): 86-95.

.... all major cities northeast of Boston in New England ) This has motivated a significant amount of research on Reasoning (Smith and Park, 1992; Egenhofer and Sharma, 1993) Query Processing (Clementini et al. 1994; Papadias et al. 1995) and Spatial Query Languages (Roussopoulos et al. 1988; Egenhofer, 1994, Papadias and Sellis, 1995) A number of relation based systems have been proposed for the representation of direction relations. Chang et al. 1987) designed the 2D strings for iconic indexing in Image Databases. A 2D string is a pair of one dimensional strings that represent the symbolic ....

Egenhofer, M., "Spatial SQL: A Query and Presentation Language", IEEE Transactions on Knowledge and Data Engineering, Vol. 6(1), pp. 86-95, 1994.

....Kansas City, MO C. Bauzer Medeiros (ed. November 1999. Research about semantic interoperability is today widespread both among the computer science community and the GIS community [5, 7, 13, 18, 20] At the same time object extraction through geographic querying has been a well studied theme [3, 8, 9, 19, 38]. In this paper we focus on the last five steps of Table 1, i.e. the direct manipulation, query, and use of extracted geographic objects. The remainder of this paper is organized as follows. Section 2 gives an overview of interoperability, object orientation, and ontologies using a GIS ....

Egenhofer, M., "Spatial SQL: A Query and Presentation Language," IEEE Transactions on Knowledge and Data Engineering, vol. 6, pp. 86-95, 1994.

....also investigate queries that involve complex spatial conditions in the form of disjunctions and conjunctions and we discuss possible extensions. 1. INTRODUCTION The representation and processing of spatial relations has gained much attention in Spatial Query Languages (Papadias and Sellis, 1995; Egenhofer, 1994), Image and Multimedia Databases (Sistla et al. 1994) Geographic Applications (Frank, 1995) Spatial Reasoning (Randell et al. 1992) and Cognitive Science (Glasgow and Papadias, 1992) Despite the attention that spatial relations have attracted in other application domains, they have not been ....

....based on mereology and expressed in a many sorted logic. Tests with human subjects have shown evidence that the 9 intersection model has potential for defining cognitively meaningful spatial predicates, a fact that makes the above relations a good candidate for commercial systems (Mark and Egenhofer, 1994). In fact, the 9 intersection model has been implemented with Geographical Information Systems (GIS) Hadzilacos and Tryfona (1992) for instance, used it to express geographical constraints, and Mark and Xia (1994) to determine spatial relations in ARC INFO. In addition there are implementations ....

Egenhofer, M. (1994) Spatial SQL: A Query and Presentation Language. IEEE Transactions on Data and Knowledge Engineering, 6(1), 86-95.

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Egenhofer MJ (1994) Spatial SQL: a query and presentation language. IEEE Transactions on knowledge and data engineering, 6(1):86--95

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M. J. Egenhofer. Spatial SQL: A query and presentation language. IEEE Transaction on Knowledge and Data Engineering, 6(1):86--95, 1994.

No context found.

M.J. Egenhofer. Spatial SQL: A Query and Presentation Language. In IEEE Transactions on Knowledge and Data Engineering, Vol.6. No.1. pp.86-95, 1994

No context found.

M. J. Egenhofer. Spatial SQL: A query and presentation language. IEEE Transaction on Knowledge and Data Engineering, 6(1):86--95, 1994.

No context found.

M. J. Egenhofer. Spatial sql: A query and presentation language. IEEE Transactions on Knowledge and Data Engineering, 6(1):86--95, February 1994.

No context found.

Egenhofer, M., Spatial SQL: A Query and Presentation Language. IEEE Trans. on Knowledge and Data Engineering, 6(1), 1994, 86-95.

No context found.

M. J. Egenhofer. Spatial SQL: A query and presentation language. IEEE Transactions on Knowledge and Data Engineering, 6(1):86--95, Feb. 1994.

No context found.

Egenhofer, M., "Spatial SQL: A Query and Presentation Language", IEEE Transactions on Knowledge and Data Engineering, vol.6, pp. 86-95, 1994.

No context found.

Egenhofer, M. (1991) Spatial SQL: A Query and Presentation Language. IEEE Transactions on Knowledge and Data Engineering, vol 6, no 1, pp 86-95.

No context found.

M. Egenhofer. Spatial SQL: A query and presentation language. IEEE Transactions on Knowledge and Data Engineering, 6(1):86---95, 1994.

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