G. R. Hjaltason, H. Samet, and Y. Sussmann., "Speeding up Bulk-Loading of Quadtrees," presented at ACM International Workshop on Advances in Geographic Information Systems, 1997.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....answering a set of sub queries with multi attribute restrictions or when further processing the stream in different sort orders than the original one. So far there has been already some work on bulk loading for multidimensional index structures, such as RTrees [8] Gridfiles [13] and quad trees [7]. These algorithms have an I O complexity of O(Plog P) for an input size of P pages, which is usually due to the fact that these approaches do not utilize a pre sorted input and thus require external sorting of the input data. For B Trees and multidimensional access methods on top of these, ....

....A2 r 1 r 1 r 2 r 3 r 1 r 1 r 2 r 3 r 2 r 3 r 4 r 5 r 6 r 7 c = 0 c = 1 c = 2 c = 6 t 5 (a) b) c) d) t 6 Figure 3 2: TempTris Algorithm for UB Trees In Figure 3 2c, t 6 is inserted and moves the sweepline to c = 2. Now the dynamic region denoted by r 3 does not intersect the cluster C [2,7] anymore. As a consequence, no more tuples may be inserted into r 3 . Thus this region is made stable, i.e. the page corresponding to that region is removed from main memory and written to disk. The stable region set now consists of Q S = r 3 , the dynamic region set is Q D = r 1 , r 2 . ....

G. R. Hjaltason, H. Samet, and Y. Sussmann., "Speeding up Bulk-Loading of Quadtrees," presented at ACM International Workshop on Advances in Geographic Information Systems, 1997.

....page filling degree. But this is not desirable. So far there has been already some work on bulk loading of multidimensional index structures. Various papers exist on this subject for other multidimensional index structures, e.g. for R Trees [21, 8, 13, 11, 6] Gridfiles [12] and quad trees [7], and now we like to address this issue for the UBTree. The contribution of this paper is to describe two simple and efficient bulk loading algorithms for the UB Tree, one for initial bulk loading and one for incremental bulk loading. We present how to reuse existing techniques, which have been ....

G. R. Hjaltason, H. Samet, and Y. J. Sussmann. Speeding up Bulk-Loading of Quadtrees. In ACM International Workshop on Advances in Geographic Information Systems, pages 50--53, 1997.

....queries. In recent years, numerous bulk loading algorithms for spatial indexes have been introduced. Most of the attention has been focused on the R tree, and related structures (e.g. 1, 2] Here we improve upon an algorithm previously developed by us for bulk loading a disk based PMR quadtree [7]. Although our presentation and experiments are in terms of the PMR quadtree, our results hold for any variant of the quadtree. In fact, our approach can be adapted to speed up the construction of many other spatial data structures based on regular partitioning, such as the buddy tree [12] and the ....

....Morton block value is represented k times in the B tree, once for each object. In the B tree, we maintain a buffer of recently used B tree nodes, and employ an LRU (least recently used) replacement policy to make space for a new B tree node. 3 Bulk Loading PMR Quadtrees The algorithm in [7] for bulk loading PMR quadtrees was based on trying to fill up memory with as much of the quadtree as possible before flushing some of its nodes into the disk based index. The key idea was to sort the input data in such a way that the portions that were written out to the disk would not be ....

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G. R. Hjaltason, H. Samet, and Y. Sussmann. Speeding up bulk-loading of quadtrees. In Proc. 5th ACM-GIS Workshop, pp. 50--53, Las Vegas, NV, Nov. 1997.

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