Y. Theodoridis and D. Papadias. Range queries involving spatial relations: A performance analysis. In Proceedings of the Second International Conference on Spatial Information Theory (COSIT'95), Semmering, Austria, September 1995.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....distinct disks they may searched in parallel. The main advantage of such an approach, which we call 2dMAP21, is that to index an MBR, all one needs to do is to use two trees instead of a specialized structure such as the R tree. The use of B trees to index MBRs has also been suggested in [TP95]. However, in that paper, the authors propose the use of four B trees, each one indexing one of the four corner coordinates that determine the MBRs . We propose the use of only two B instead. Moreover, we explore the partitioning of such trees in order to allow parallel access. Such ....

....of the four corner coordinates that determine the MBRs . We propose the use of only two B instead. Moreover, we explore the partitioning of such trees in order to allow parallel access. Such issues of partitioning the data and parallelization of the host B trees were not touched upon in [TP95]. Some work has been done regarding the parallelization of the R tree [KF92] where the main focus was to find an efficient algorithm to place a newly created tree node once a split occurs. The algorithm requires a large overhead during node splits, which may involve several disks, and is also ....

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Y. Theodoridis and D. Papadias. Range queries involving spatial relations: A performance analysis. In Proceedings of the Second International Conference on Spatial Information Theory (COSIT'95), Semmering, Austria, September 1995.

.... More specifically, a rectangle ( soccer field ) covers two rectangles ( host and guest area ) which in turn cover a rectangle ( penalty area ) Again the inner rectangle ( penalty area ) covers most inner rectangle ( goal area ) Above spatial relationship representations used by GIS community [7, 8] are not enough to express image contents because it lacks expressive power. Figure 1 and 2 have the same shapes and same spatial relationships even if they are different. Without new spatial relationships we cannot express the image contents properly. Therefore we propose the contents, we have to ....

....storing very high dimensional data. Jong Yoon et al. present the 3 dimensional BitCube that is 3 dimensional indexing mechanism for XML [10] number of researchers in spatial and image databases. The most common types of spatial relationships include direction, distance and topological relations [7]. 3. Preliminaries 3.1 Spatial Relationship We frequently mention an object based on its directional relationship with another object. Egenhofer [8] uses the concepts of boundary and interior of point sets to derive topological relationships between two dimensional regions (point sets) embedded ....

Yannis Theodoridis and Dimitris Papadias. Range Queries Involving Spatial Relations: A Performance Analysis. Spatial Information Theory, Lecture Notes in Computer Science no. 988, pages 537-551. Springer-Verlag, 1995.

.... eight possible primitive topological relationships (disjoint, meet, overlap, covers, coveredBy, contains, inside and equal) EF95] EM95] and eight possible directional relationships (north, south, east, west, north east, north west, south east and south west) between the two objects [JTS96] TP95] and two special relationships of same longitude and same latitude. Since it is possible for two regions to have both kinds of relationships, each combination of a topology and a direction forms a primitive spatial relation (SPRIM) in our spatial model. Egenhofer et al. [PTSE95] extended Allen s ....

Y. Theodoridis and D. Papadias. Range queries involving spatial relations: A performance analysis. In Proceedings of the 2nd International Conference on Spatial Information Theory, COSIT, Semmering, Austria, 1995. Springer-Verlag.

....system. One of the goals of our work is thus to enhance the dynamic sliders for such continuous spatial queries. 2.2 Spatial Query Types Spatial queries are often processed qualitatively with the use of spatial relations. Spatial relations can be broadly classified into three basic categories [TP95] ffl Topological Relations ffl Directional Relations ffl Distance Relations 2.2.1 Topological Relations Topological relations are those spatial relations which are preserved under groups of continuous transformations such as translation and rotation. In other words, if both the objects are ....

....relationship between two pairs of point sets. 2.2.2 Directional Relations Directional relations are those spatial relations that deal with order in space between two objects. There are essentially two broad categories for directional relations that are commonly used in the literature [JTS96] TP95] ffl 4 way direction (North, South, East, West) ffl 8 way direction (North, South, East, West, North East, North West, South East, South West) The choice between these two models of directional relations depends on the level of granularity or precision at which these relations are to be ....

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Y. Theodoridis and D. Papadias. Range queries involving spatial relations: A performance analysis. In Proceedings of the 2nd International Conference on Spatial Information Theory, COSIT, Semmering, Austria, 1995. Springer-Verlag.

.... tree to index MBRs. Although DOT is shown to outperform the classical R tree [3] it is doubtful whether it can outperform the R tree (given the results in [2] The issue of parallelizing DOT s approach was not investigated. The use of B trees to index MBRs has also been suggested in [13]. However, in that paper, the authors propose the use of four B trees, each one indexing one of the corner coordinates that determine the MBRs. We propose the use of only two such trees instead. Moreover, the idea of parallelizing access to the the host B trees was not touched upon in ....

....However, in that paper, the authors propose the use of four B trees, each one indexing one of the corner coordinates that determine the MBRs. We propose the use of only two such trees instead. Moreover, the idea of parallelizing access to the the host B trees was not touched upon in [13]. Some work has been done regarding parallel R trees [6] Even though that research has shown that parallel R trees may yield much better performance than a non parallel Rtree, it is likely that more than two parallel R trees would be needed to provide performance comparable to a single ....

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Theodoridis, Y., and Papadias, D. Range queries involving spatial relations: A performance analysis. In 2nd COSIT (Semmering, Austria, September 1995).

....memory and use only the MBR of the leaf node for the current level processing such as DVO, PSO and IPF with other non leaf node entries. The processing for the entries of the leaf node is delayed until all leaf nodes are met. For other spatial predicates, we consider the spatial relationships of [19]. According to [19] the spatial relationships are classified as topological, distance and direction relationships as follows: ffl Topological relationship: disjoint, meet, equal, overlap, contains, inside, covers, and covered by. ffl Distance relationship: near, and far. ffl Direction ....

....the MBR of the leaf node for the current level processing such as DVO, PSO and IPF with other non leaf node entries. The processing for the entries of the leaf node is delayed until all leaf nodes are met. For other spatial predicates, we consider the spatial relationships of [19] According to [19], the spatial relationships are classified as topological, distance and direction relationships as follows: ffl Topological relationship: disjoint, meet, equal, overlap, contains, inside, covers, and covered by. ffl Distance relationship: near, and far. ffl Direction relationship: north, south, ....

Y. Theodoridis and D. Papadias, "Range Queries Involving Spatial Relations: A Performance Analysis," Proc. of the 2nd International Conference on Spatial Information Theory, 1995.

....A s geometry. Orientation Operators The orientation operators verify whether there exists a specific orientation relationship between two sets of geometric objects [PS94] or deal with relative order in space [PTS94] For simplicity we used the following operators (based on definitions in [TP95] note that several other operators can be built upon these) ffl NORTH (A,B) returns true if all elements of A have a North relationship with all elements of B, and ffl EAST (A,B) defined similarly as NORTH but with respect to East direction. Metric Operators The metric operators return ....

Y. Theodoridis and D. Papadias. Range Queries Involving Spatial Relations: A Performance Analysis. In Proc. of the 2nd European Conf. on Spatial Information Theory, number 988 in LNCS, pages 537-- 551, 1995.

....more recent work upon R trees have designed more efficient R tree derivatives . Such as the R tree [SRF87] and the R tree [BKSS90] We review them briefly in Appendix A. 2) It has been well argued in the literature that R trees perform better than R trees and R trees [BKSS90, TP95, KSCL95] We thus chose to use the R tree There are other techniques for indexing spatial data. Among those we can cite those based on mapping N dimensional objects to points in the N dimensional space, such as the Z ordering [Ore86] and the DOT approach [FR91] The Z ordering transforms a ....

Y. Theodoridis and D. Papadias. Range queries involving spatial relations: A performance analysis. In Proceedings of the 2nd International Conference on Spatial Information Theory (COSIT'95), Semmering, Austria, September 1995.

....other queries of interest, such as topological queries of high resolution (meet, covers, etc. direction (north, northeast, etc. or distance (near, nearest, etc. queries. Preliminary results that estimate the cost of several representative direction and distance relations are presented in [Theo95]. Besides query optimization solutions, the proposed analytical model could be also useful to the construction of an efficient R tree. Since the cost formula estimates the number of disk accesses, which is the primary factor for the efficiency of the tree structures, a transformation of that ....

Y. Theodoridis, D. Papadias, "Range Queries Involving Spatial Relations: A Performance Analysis", Proceedings of the 2nd COSIT Conference, 1995.

....expected cost for the query window Q, which equals to the expected cost C(R) for the retrieval of a spatiotemporal operator R. The accuracy of the above analytical model has been already evaluated on spatial relationships of varying selectivity (e.g. inside, near, northeast, and combinations) in [Theo95b]. Intuitively, we assume that the unified scheme should be the most efficient one when both spatial and temporal information are included in the query while in the rest cases the simple scheme seems to be preferable. The accuracy of these intuitive conclusions will be examined in the next ....

Y. Theodoridis, D. Papadias, "Range Queries Involving Spatial Relations: A Performance Analysis", Proceedings of the 2nd International Conference on Spatial Information Theory (COSIT), 1995.

....query window q and compare it with each node rectangle P while traversing the R tree. Formally, OP(P,q) overlap(P,Q) The above transformation also works well for the analytical estimation of the range query cost since the relative error of the estimation is similar to that of range queries [TP95]. Hence we argue that the above transformation could also work well for spatial joins. ii) The representativeness of the overlap operator for the accuracy of the spatial join cost estimation is analogous to its representativeness for the accuracy of the range query cost estimation since we ....

Y. Theodoridis, D. Papadias, "Range Queries Involving Spatial Relations: A Performance Analysis", Proceedings of the 2nd Conference on Spatial Information Theory (COSIT), 1995. ##

....topological (meet, covers, etc. directional (north, northeast, etc. or distance (near, nearest, etc. information. We have already adapted the model to estimate the cost of (a) several representative direction and distance relations on GIS applications with random (uniform like) datasets [TP95] and (b) spatio temporal relations between objects of large Multimedia applications [TVS96] by handling such relations as range queries with an appropriate transformation of the query window q. Finally, besides query optimization, the proposed analytical model could also be useful to the ....

Y. Theodoridis, D. Papadias, "Range Queries Involving Spatial Relations: A Performance Analysis", In Proceedings of the 2nd International Conference on Spatial Information Theory (COSIT), September 1995.

....space, involving topological (meet, covers, etc. directional (north, northeast, etc. or distance (near, nearest, etc. information. Preliminary results that estimate the cost of several representative direction and distance relations on random (uniform like) datasets are presented in [Theo95b]. Finally, besides query optimization, the proposed analytical model could also be useful to the construction of an efficient R tree. Since the cost formula estimates the number of disk accesses, which is the primary factor for the efficiency of the tree structures, a transformation of that ....

Y. Theodoridis, D. Papadias, "Range Queries Involving Spatial Relations: A Performance Analysis", Proceedings of the 2nd COSIT Conference, 1995.

....Data Structures, Performance Analysis, Query Optimisation. A short version of this paper has been submitted to the 12th IEEE International Conference on Data Engineering [Theo95a] Some parts of the performance analysis appear in the Proceedings of the 2nd Conference on Spatial Information Theory [Theo95c]. Yannis Theodoridis and Timos Sellis were partially supported by the Department of Research and Technology of Greece (PENED 91) and by the European Commission under the ESPRIT Basic Research project AMUSING (EP6881) Dimitris Papadias was partially supported by NSF IRI 9221276. 2 1. ....

Theodoridis, Y., Papadias, D., "Range Queries Involving Spatial Relations: A Performance Analysis", In the Proceedings of the 2nd International Conference on Spatial Information Theory (COSIT), 1995.

....to be defined in order to retrieve a multidimensional (topological, directional or distance) operator OP, instead of the classic overlap operator. The above transformation has been already adopted for the analytical cost estimation of several queries in GIS applications of dimensionality n = 2 [TP95] and n = 3, 4 [PTS97] On the other hand, based on the corresponding formula for the selectivity estimation of a range query [TS96] we aim at a formula that would estimate the number of overlapping pairs of objects at the leaf level of the two indexes based on the roles of the data and the ....

Y. Theodoridis, D. Papadias, "Range Queries Involving Spatial Relations: A Performance Analysis", Proc. 2nd COSIT Conf., 1995.

....constraints and the axes involved differ. The performance of each indexing method is expected to be similar for relations with similar range constraints. Therefore the behaviour of an indexing method to any spatial relation can be predicted from other relations with similar range characteristics [35]. Because MBRs differ from the actual objects they enclose, they are not always adequate to express the relation between the actual objects. For this reason, spatial queries involve the following two step strategy [12, 22] First a filter step based on MBRs is used to rapidly eliminate MBRs of ....

Y. Theodoridis and D. Papadias, Range Queries Involving Spatial Relations: A Performance Analysis, in: Proc. COSIT'95, Lecture Notes in Computer Science, Vol. 988 (Springer, Berlin, 1995) 537-551.

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