Encoded Bitmap Indexing for data warehousingProblemData WarehousingTuple-basedMetrics TablesBitmappingEncoding TechniquesThe PaperCritiqueSlide 10ContributionsPresented by Russell MyersPaper by Ming-Chuan Wu and Alejandro P. BuchmannProblemOptimizations and tuning designed for On-Line Transaction Processing rather than Data WarehousesData Warehouses have specific needsComplex queriesHuge volume of data returned as well as updatedDatabase systems generally not built for image dataData WarehousingHow do we retrieve data efficiently based on various metrics?Represented as a portion of the tupleRepresented in metrics tablesRepresented as a defined data range (e.g. bitmaps)Tuple-basedIncluding the metrics directly in the tupleHard to index based on and search throughNot easily updated and costs a lot of storage space (e.g. have to insert new metrics for every tuple)Traverse in linear timeMetrics TablesData could be represented in associative metrics tablesLess data to store – just associations and the metric dataQuicker search – follow the metric to all the primary keys of the individual pieces of dataStill linearBitmappingEach tuple contains a small portion of encoded bitmap dataCan organize the bitmap into decision trees and use to search – less timeInsertion and amount of data is lessenedSlice the data into various portions to represent multiple metrics and search through thoseEncoding TechniquesHierarchical encodingEx: Region to district to storeRangeEliminate searching from things outside of a range (e.g. searching between 10 and 13 and excluding all others)OrderingThe PaperThe paper seeks to prove that bitmapping techniques are the way to goPerformance analysis of various bitmapping techniquesProofs of operations timesCritiqueExcellent startExplained the topic clearlyMade the basis of the paper easy to understandConfounding expansionConfused by directionDifferences between various bitmap techniques?CritiqueBit slicingMapping techniquesRepresentations of bitmapsMetric graphical representationAdvantages to different encoding techniquesContributionsBitmap indexing and tree structures bring faster data resultsMuch cleaner than alternative meansEasily representedMapping situations are smaller than representing each piece of
View Full Document
Unlocking...