Performances of Multi-Level and Multi-Component Compressed BitmapIndices

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This paper presents a systematic study of two large subsetsof bitmap indexing methods that use multi-component and multi-levelencodings. Earlier studies on bitmap indexes are either empirical or foruncompressed versions only. Since most of bitmap indexes in use arecompressed, we set out to study the performance characteristics of thesecompressed indexes. To make the analyses manageable, we choose to use aparticularly simple, but efficient, compression method called theWord-Aligned Hybrid (WAH) code. Using this compression method, a numberof bitmap indexes are shown to be optimal because their worst-case timecomplexities for answering a query is a linear function of the number ofhits. Since compressed ... continued below

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Wu, Kesheng; Stockinger, Kurt & Shoshani, Arie April 30, 2007.

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Description

This paper presents a systematic study of two large subsetsof bitmap indexing methods that use multi-component and multi-levelencodings. Earlier studies on bitmap indexes are either empirical or foruncompressed versions only. Since most of bitmap indexes in use arecompressed, we set out to study the performance characteristics of thesecompressed indexes. To make the analyses manageable, we choose to use aparticularly simple, but efficient, compression method called theWord-Aligned Hybrid (WAH) code. Using this compression method, a numberof bitmap indexes are shown to be optimal because their worst-case timecomplexities for answering a query is a linear function of the number ofhits. Since compressed bitmap indexes behave drastically different fromuncompressed ones, our analyses also lead to a number of new methods thatare much more efficient than commonly used ones. As a validation for theanalyses, we implement a number of the best methods and measure theirperformance against well-known indexes. The fastest new methods arepredicted and observed to be 5 to 10 times faster than well-knownindexing methods.

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  • Report No.: LBNL--60891
  • Grant Number: DE-AC02-05CH11231
  • DOI: 10.2172/920347 | External Link
  • Office of Scientific & Technical Information Report Number: 920347
  • Archival Resource Key: ark:/67531/metadc899936

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  • April 30, 2007

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  • Sept. 27, 2016, 1:39 a.m.

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  • Sept. 29, 2016, 3:53 p.m.

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Wu, Kesheng; Stockinger, Kurt & Shoshani, Arie. Performances of Multi-Level and Multi-Component Compressed BitmapIndices, report, April 30, 2007; Berkeley, California. (digital.library.unt.edu/ark:/67531/metadc899936/: accessed August 20, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.