Wavelet synopses with error guarantees

Recent work has demonstrated the effectiveness of the wavelet decomposition in reducing large amounts of data to compact sets of wavelet coefficients (termed "wavelet synopses") that can be used to provide fast and reasonably accurate approximate answers to queries. A major criticism of such techniques is that unlike, for example, random sampling, conventional wavelet synopses do not provide informative error guarantees on the accuracy of individual approximate answers. In fact, as this paper demonstrates, errors can vary widely (without bound) and unpredictably, even for identical queries on nearly-identical values in distinct parts of the data. This lack of error guarantees severely limits the practicality of traditional wavelets as an approximate query-processing tool, because users have no idea of the quality of any particular approximate answer. In this paper, we introduce Probabilistic Wavelet Synopses, the first wavelet-based data reduction technique with guarantees o...

• Type: Conference
• Year: 2002
• Where: SIGMOD
• Authors: Minos N. Garofalakis, Phillip B. Gibbons
• Keywords: Database, Individual Approximate Answers, Probabilistic Thresholding Scheme, Probabilistic Wavelet Synopses, SIGMOD 2002