J. Nievergelt, H. Hinterberger, and K. C. Sevcik. The grid file: An adaptable symmetric multikey file structure. ACM Transactions on Database Systems, ; ACM CR 8411-0931, 1984.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....uses the CLOCK policy. We use the MLGF for the experiments here, but our methodology is applicable to other kinds of DIP multidimensional files. Multidimensionl files that obey the two rules in Lemma 1 can be DIP multidimensional files. The buddy tree [19] the quad tree [18] and the grid file [16] are examples. On the other hand, some cannot be made DIP multidimensional files. The R # tree [3] is an example. 2) DIP Aggregation This algorithm uses the same aggregation windows as those of the One Pass Aggregation algorithm. But, it traverses the aggregation windows using the Hilbert order ....

Nievergelt, J., Hinterberger, H., and Sevcik, K.C., "The Grid File: An Adaptable, Symmetric Multikey File Structure," ACM Trans. on Database Systems, Vol. 9, No. 1, pp. 38--71, Mar. 1984.

....secondary storage. However, the practical need for good I O support has led to the development of a large number of external data structures, which do not have good theoretical worst case bounds but have good average case behavior for common spatial database problems. These includes the grid file [NHS], various quad trees [Sama, Samb] z orders [Ore] and other space filling curves, k d B trees [Rob] hB trees [LoS] cell trees [Gun] and various R trees [Gut, SRF] For these external data structures there has been a lot of experimentation but relatively little algorithmic analysis. Their ....

J. Nievergelt, H. Hinterberger, and K. C. Sevcik, "The Grid File: An Adaptable, Symmetric Multikey File Structure," ACM Transactions on Database Systems 9(1) (1984), 38--71. 10

....in the sense that they are pinned to all two classifying properties, that is, their directory regions are hyper rectangular and complete. They perform rather efficiently for uniform and uncorrelated data. However, for highly correlated data their 3 A property rectangular complete grid file [19], BMEH tree [21] K D B tree [25] MB tree [32] C2 BANG file [8] hB tree [16] BV tree [9] zkdb tree [20] C3 buddy tree [28] multilevel grid file [29] G tree [15] C4 HG tree Table 1 Classification of multidimensional PAMs performance degenerates. Grid files partition a data space ....

J. Nievergelt, H. Hinterberger, and K.C. Sevcik, "The grid file: an adaptable, symmetric multikey file structure," ACM Transactions on Database Systems, Vol. 9, No.1, pp. 38-71, 1984.

....in SMA index organization is simpler than that in MSA index organization. 3. 3 Keyword Indexes The signature file has proved to be a convenient indexing technique for text data and multiattribute retrieval [23, 24, 25, 26, 27, 28] Multidimensional index structures such as K D B tree, grid file [29], R tree, and R tree are not appropriate for indexing text data represented by keywords, because they assume that the dimensionality of the domain space, which can be interpreted as the number of keywords in the case of keyword indexing, is small and constant. The number of keywords given by ....

J. Nievergelt, H. Hinterberger, and K.C. Sevcik, "The grid file: an adaptable, symmetric multikey file structure," ACM Transactions on Database Systems, 9(1), 1984, 38-71.

....and Roseman, 1989; Moon et al. 1996) and hence is best suited for the purpose. 2. 2 Multidimensional Access Structures There are two basic ways to organise multidimensional feature vectors: organising the embedding space within which the vectors reside or organising the vectors themselves (Nievergelt et al. 1984). For high dimensional data, the data space increases exponentially and it appears there is no data structure based on this organisation that can scale up to this space. A very thorough survey of multidimensional access method has recently been done by Gaede and Gunther (1995) Figure 4: The ....

NIEVERGELT, J., HINTERBERGER, H., and SEVCIK, K. C. (1984). The grid file: An adaptable symmetric multikey file structure. ACM Transactions on Database Systems, 9(1).

....step itself is ignored because it is too domain specific. Various solutions to the problem of multidimensional search have been proposed. First, we may classify the solutions according to the value d. If d is sufficiently small, e.g. 3, we are able to use index structures such as the grid file (Nievergelt, et al. 1984), the hB tree (Lomet Salzberg, 1989) the kd tree (Bentley, 1975; Bentley, 1979) or the R tree (Beckmann, et al. 1990) However, if d is quite large, e.g. 16, these index structures do not provide adequate performance. The reasons for this degeneration of performance are subsumed by the ....

Nievergelt J., Hinterberger H., Sevcik K. C. (1984). "The Grid File: An Adaptable, Symmetric Multikey File Structure" in {ACM Trans. on Database Systems}, Vol. 9, No. 1, pp. 38-71.

....is the major drawback of the inverted lists approach. Multidimensional index structures have been developed as an efficient alternative approach for multidimensional query processing. The basic idea of multidimensional index structures such as space filling curves [14, 8] grid file based methods [13, 5], and R tree based methods [7, 2] is to use one multi attribute index which provides efficient access to an arbitrary combination of attributes. Proc. 2nd Int. Conf. on Data Warehousing and Knowledge Discovery (DaWaK) 2000 It is well known that multidimensional index structures are very ....

....is independent of the multidimensional index structure used. Any multidimensional index structure such as the R tree [7] and its variants (R tree [17] R tree [2] P tree [9] Buddy tree [16] linear quadtrees [6] z ordering [14] or other space filling curves [8] and gridfile based methods [13, 5] may be used for this purpose. Before we describe our theoretical model, we first provide a simple algorithm for processing queries using striped trees. As the single indexes do not have all information about an object, but only about some attributes of the object, in general, we have to query ....

Nievergelt J., Hinterberger H., Sevcik K. C.: `The Grid File: An Adaptable, Symmetric Multikey File Structure', ACM Trans. on Database Systems, Vol. 9, No. 1, 1984, pp. 38-71.

.... above the Storage Object Manager is a collection of access methods that provide associative access to files of storage objects and further support for versioning (if desired) For access methods, EXODUS will provide a library of type independent index structures including B trees, Grid files [Niev84], and linear hashing [Litw80] These access methods will be implemented using the type parameter capability provided by the E language (as described in Section 5) This capability enables existing access methods to be used with DBI defined abstract data types without modification as long as ....

.... based on some form of dynamic hashing are usually sufficient for conventional business database systems (e.g. a relational DBMS) a database system for storing and manipulating spatial data is likely to need a spatial index structure such as the KDB tree [Robi81] R tree [Gutt84] or Grid file [Niev84] structures. We plan to provide a library of available access methods in EXODUS, but we expect this library to grow new, specialized index structures will undoubtedly continue to be developed as emerging database applications seek higher and higher performance. A complication is that a given ....

Nievergelt, J., H. Hintenberger, H., and Sevcik, K.C., "The Grid File: An Adaptable, Symmetric Multikey File Structure," ACM Transactions on Database Systems, Vol. 9, No. 1, March 1984.

....The spatial join index [3] method builds a spatial version of a join index [4] for two data sets if these datasets are frequently joined spatially. This method trades the overhead of pre computation at index building time for accelerated processing at join invocation time. It assumes the grid file [5] as the underlying spatial access method, and requires grid files to exist for rele 2 vant data sets before spatial join indices can be built for them. A similar method using distance associated join indices [6] has also been proposed to speed up spatial range queries. Orenstein [7] 8] 9] ....

J. Nievergelt, H. Hinterberger, and K. C. Sevcik, "The grid file: An adaptable, symmetric multikey file structure, " ACM Transactions on Database Systems, vol. 9, no. 1, , 1984.

....Data Option. INFORMIX (Stonebraker 1997) makes use of data blades that combine a hierarchy of minimum bounding boxes (often known as an R tree (Guttman 1984) with a B tree access structure. ESRI makes use of a two level grid (as well as a three level grid) which is a variant of a grid file (Nievergelt, Hinterberger Sevcik 1984) that uses a regular decomposition partition. The result is known as SDE denoting Spatial Data Engine. Although we have mentioned a number of general representations above, actual implementations make use of variants of these representations. The relationship between these variants is not ....

Nievergelt, J., Hinterberger, H. & Sevcik, K. C. (1984), `The grid file: an adaptable, symmetric multikey file structure', ACM Transactions on Database Systems 9(1), 38--71.

....is such that its MBRs can be held in a single disk page. The grid of cells may be regular or not. A grid directory may be associated with the grid of cells. The various hash based structures differ on the grid( directory) structure. Since the initial well known Fixed Grid [BF79] and Grid File [NHS84] numerous variants have been proposed , the most complex of which resemble the tree based structures descibed below. Examples of hash based variants are the Twin Grid File [HSW88] PLOP Hashing [KS88] Excell, the Two Level Grid File, the Bang File, the Multi Layer Grid File, the R File, MOLHPE, ....

J. Nievergelt, H. Hinterger, and K.C. Sevcik. The Grid File: An Adaptable Symmetric Multikey File Structure. ACM Trans. on Database Systems, 9(1):38--71, 1984.

....in geographic space, x,y coordinates for each node are also stored in the record. AB tree with Z ordering [22] of the x, y coordinates is used to order the secondary index. It can support point and range queries on spatial databases. Other access methods such as R tree [11] and Grid File [21], etc. can alternatively be created on top of the data file as secondary indices in CCAM to suit the application. Example: In figure 1, a sample network and its CCAM is shown. We assume that the Z order of the node id values is represented by the alphabetical order of the node names. The dashed ....

J. Nievergelt, H. Hinteberger, and K.D. Sevcik. "The Grid File: An Adaptable, Symmetric Multi-Key File Structure". ACM Trans. on Database Systems, 9(1):38--71, 1984.

....be able to direct the search more efficiently in the directions that the user can be inferred to be pursuing. The second important research question is finding efficient structures with which to represent and search N space. The database literature suggests several multidimensional structures [46, 86, 30], but in practice, these become less effective at dimensions higher than three, and we are using dimensions of ten to twenty. Furthermore, for dimensions greater than or equal to three, there is no known algorithm for nearest neighbor searching that is both linear in space and polylogarithmic in ....

J. Nievergelt, J. Hinterberger, and K. Sevcik. The grid file: An adaptable symmetric multikey file structure. ACM Transactions on Database Systems, 9(1), 1984.

....efficient data structures for maintainining large sets of multi dimensional (spatial) data, such as points or regions, is of crucial importance in several applications, including Spatial, Image or Multimedia Database Systems. In recent years, several data structures have been developed for point [Niev84, Free87, Henr89] and non point [Gutt84, Sell87, Gunt89, Beck90] spatial objects. All these indexing methods use several heuristics to index spatial data efficiently. The large number of spatial data structures proposed indicate that, today, research in this field should turn to the development of powerful ....

....2. Basic Concepts and Related Work Spatial data structures cluster geometric objects in data buckets according to spatial locality. Buckets divide the work space in disjoint or overlapping bucket regions. Disjointness of bucket regions is a rule for point data structures, such as Grid file [Niev84] and variants, but for non point data structures it is the exception of the rule (R tree [Sell87] and Cell tree [Gunt89] are examples of this type) Most non point data structures, such as R tree [Gutt84] and variants based on the 3 original method, support overlapping bucket regions in ....

J. Nievergelt, H. Hinterberger, K.C. Sevcik, "The Grid File: An Adaptable, Symmetric Multikey file Structure", ACM Transactions on Database Systems, vol.9(1), March 1984, pp. 38-71.

....is partitioned into a minimal set of rectangles R 1 , R 2 , R k , where: 3 k R = U R i , k 1 i=1 so that each R i , 1 i k, intersects with exactly one disjoint region. These rectangles are represented in a file and may be organized by any multidimensional PAM, like the grid file [Niev84] or the K DB tree [Robi81] Examples of SAMs using the clipping technique are the R tree [Sell87] and the Cell tree [Gunt89] Since these structures avoid overlapping regions the search operation is very efficient. Additionally, the properties of the underlying PAM are inherited. However, a ....

....k extents of the MBR) and thus it can be considered as a point in a 2k dimensional space. For instance, a set of 2 d MBRs may be represented by an equal in number set of points in the 4 d space. The higher dimensionality points can be organized by any multidimensional PAM, such as the grid file [Niev84]. In analogy to the overlapping technique, the MBRs are uniquely represented in the file. Additionally, all properties of the underlying PAM are inherited to the SAM. The drawbacks of the transformation technique are that, first, the formulation of spatial queries in the point space is much more ....

J. Nievergelt, H. Hinterberger, K.C. Sevcik: `The Grid-File: An Adaptable, Symmetric Multikey File Structure', ACM Transaction on Database Systems, Vol.9, No.1, 38-71, 1984.

....the z ordering technique is used to transform multi dimensional data into the 1 dimensional domain. Spatial join is then conducted on the B tree structures that store z ordering values of the spatial data. In [21] spatial join indexes are computed over spatial data indexed by Grid files [17]. In [16] spatial join is conducted to create the distance associated indexes for spatial range queries. In [7] a model of the generalization tree is proposed to compare the tree based spatial joins with the alternative approaches using cost estimation. Spatial join based on depth first ....

Nievergelt, J. and Hinterberger, H., "The Grid File: A Adaptable, Symmetric Multikey File Structure", ACM Transactions on Database Systems, Vol. 9, No. 1, Mar. 1984, pp. 39 -- 71.

.... access methods capture the isotropic nature of proximity by recursively dividing the space, using a splitting rule to construct a grid or a hierarchy of regions [17] A survey of these methods can be found in [34] Some of the representative Isotropic Access Methods (ISM s) include grid files [31], cell trees [17] R trees [18] and R trees [36] Isotropic spatial access methods have traditionally been used to store vector spatial data such as sets of polygons, and they allow flexible policies which can be adapted to take advantage of connectivity information. The literature on ....

....and Get successors( operations. The choice of a secondary index can be tailored to the application. We use the B tree with Z order [32] in our experiments, since the benchmark networks are embedded in geographical space. Other access methods such as the R tree [18] and Grid File [31], etc. can alternatively be created on top of the data file, as secondary indices in CCAM to suit the application. In this section, we describe the file structure and procedures used to implement the various operations on networks. 3.1 Connectivity Clustered Data File For each node, a record ....

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J. Nievergelt, H. Hinteberger, and K.D. Sevcik. "The Grid File: An Adaptable, Symmetric Multi-Key File Structure". ACM Trans. on Database Systems, 9(1):38--71, 1984.

....also facilitate the characterization of the dominance region of the proposed method in the context of multi dimensional data. In the future, we intend to extend the comparisons to other domains. 6. 1 Parallelizing Grid Files We apply the max cut declustering scheme to parallelizing Grid files [28], a well known access method for multi dimensional and spatial data. Multi dimensional data refers to a collection of data values embedded in a coordinate space which has dimension 2. The Grid file partitions the coordinate space into rectangular grids called cells. We will work with a ....

....query. Most existing declustering methods for grid files [18, 36] are based on coordinate mapping of the data pages in the grid directory to the disk id, assuming that the data are uniformly distributed. However, for many nonuniform distributions, multiple grid cells may need to share a disk block [28], and the mapping function based methods will then need to resolve conflicts. In addition, the mapping based methods need to be extended to deal with the splitting and merging that result from updates, since these events may change the grid coordinates of existing data pages. Parallel ....

J. Nievergelt, H. Hinteberger, and K.D. Sevcik. "The Grid File: An Adaptable, Symmetric Multi-Key File Structure". ACM Trans. on Database Systems, 9(1):38--71, 1984.

....be used to retrieve set of objects in the current 3 D spatial area of attention. Similarly, during battle planning, such an index structure can be used to identify regions of significant enemy presence. Many multidimensional index structures have been developed in the literature (e.g. grid files (Nievergelt, et. al, 1984), R trees (Guttman, 1984) hB trees (Evangelidis, et al. This work was supported by Army Research Laboratory under Cooperative Agreement No. DAAL0196 2 0003. 1995) Despite extensive research, none of the developed data structures are supported in existing commercial database management ....

Nievergelt, J., Hinterberger, H. & Sevcik, K.C. (1984), "The Grid File: An Adaptable, Symmetric Multikey File Structure.", ACM Transactions on Database Systems, 1984.

....(rectilinear) shapes to obtain a terse shape description. Jagadish [16] assumes that all general shapes can be approximated by a fine enough rectilinear staircase . A shape is represented as a point in multi dimensional space, so that any multi dimensional point access method (PAM) [30, 33, 35] can be used for indexing. However, this rectilinear approach can not deal with the shape rotations. Finally, Mallat [22] considers using the coefficients of the 2 D Discrete Fourier Transformation or Discrete Wavelet Transformation as shape descriptors. Local features are structure features ....

J. Nievergelt, H. Hinterberger, and K. Sevcik. The Grid File: An Adaptable Symmetric Multikey File Structure. ACM Transactions on Database Systems, 9(1):38--71, 1984.

....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 (R tree[7] R tree, R tree[8] Grid File[9] , Quad tree) line segments, rectangles, polyg ons, networks (CCAM) and images, Trade offs in approximate geometry, clipping, overlapping regions, transformation to higher dimension space etc. 6. Query Processing Steps, CPU and I O costs, Strategies for range query over points polygons, spatial ....

J. H. Nievergelt, Hinterberger, and K. C. Sevcik, The Grid File: An Adaptable Symmetric Multikey File Structure, TODS 9(1)ACM, (1984).

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J. Nievergelt, H. Hinterberger, and K. C. Sevcik. The grid file: An adaptable symmetric multikey file structure. ACM Transactions on Database Systems, ; ACM CR 8411-0931, 1984.

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J.Nievergelt, H. Hinterberger, K.C. Sevcik, "The Grid File: An Adaptable, Symmetric Multikey File Structure", ACM Transactions on Database Systems, Vol.9, No.1, pp.38-71, March 1984.

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Nievergelt, J., Hinterberger, H., Sevcik, K. (1984). The grid file: an adaptable symmetric multikey file structure. ACM Transactions on Database Systems, 9(1), 38-71.

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J. Nievergelt, H. Hinterberger, "The Grid File: An Adaptable, Symmetric Multikey File Structure," ACM Transactions on Database Systems, Vol. 9, No. 1, March 1984, pp. 38-71.

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