Chang Ge, Martin Kaufmann, Lukasz Golab, Peter M. Fischer, Anil K. Goel
{"title":"Indexing bi-temporal windows","authors":"Chang Ge, Martin Kaufmann, Lukasz Golab, Peter M. Fischer, Anil K. Goel","doi":"10.1145/2791347.2791373","DOIUrl":"https://doi.org/10.1145/2791347.2791373","url":null,"abstract":"Bi-temporal databases support system (transaction) and application time, enabling users to query the history as recorded today and as it was known in the past. In this paper, we study windows over both system and application time, i.e., bi-temporal windows. We propose a two-dimensional index that supports one-time and continuous queries over fixed and sliding bi-temporal windows, covering static and streaming data. We demonstrate the advantages of the proposed index compared to the state-of-the-art in terms of query performance, index update overhead and space footprint.","PeriodicalId":225179,"journal":{"name":"Proceedings of the 27th International Conference on Scientific and Statistical Database Management","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134525778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"FiND: a real-time filtering by novelty and diversity for publish/subscribe systems","authors":"Zeinab Hmedeh, C. Mouza, Nicolas Travers","doi":"10.1145/2791347.2791356","DOIUrl":"https://doi.org/10.1145/2791347.2791356","url":null,"abstract":"Content syndication has become a popular way for timely delivery of frequently updated information on the Web. It essentially enhances traditional pull-oriented searching and browsing of web pages with push-oriented protocols. However many Web syndication applications imply a tight coupling between feed producers and consumers and do not help users to find, in all information they received, items with interesting and new content. We present the FiND Pub/Sub system which integrates an in-memory filtering process based on keyword subscriptions. Unlike existing proposals, FiND is designed for real-time notifications on item streams. This demonstration illustrates the main features of the FiND system namely (i) a scalable real-time notification process when the most important terms of the subscription are matched, (ii) a tunable filtering by novelty and diversity to reduce user flooding.","PeriodicalId":225179,"journal":{"name":"Proceedings of the 27th International Conference on Scientific and Statistical Database Management","volume":"55 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133651675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
David A. Boyuka, Houjun Tang, Kushal Bansal, Xiaocheng Zou, S. Klasky, N. Samatova
{"title":"The hyperdyadic index and generalized indexing and query with PIQUE","authors":"David A. Boyuka, Houjun Tang, Kushal Bansal, Xiaocheng Zou, S. Klasky, N. Samatova","doi":"10.1145/2791347.2791374","DOIUrl":"https://doi.org/10.1145/2791347.2791374","url":null,"abstract":"Many scientists rely on indexing and query to identify trends and anomalies within extreme-scale scientific data. Compressed bitmap indexing (e.g., FastBit) is the go-to indexing method for many scientific datasets and query workloads. Recently, the ALACRITY compressed inverted index was shown as a viable alternative approach. Notably, though FastBit and ALACRITY employ very different data structures (inverted list vs. bitmap) and binning methods (bit-wise vs. decimal-precision), close examination reveals marked similarities in index structure. Motivated by this observation, we ask two questions. First, \"Can we generalize FastBit and ALACRITY to an index model encompassing both?\" And second, if so, \"Can such a generalized framework enable other, new indexing methods?\" This paper answers both questions in the affrmative. First, we present PIQUE, a Parallel Indexing and Query Unified Engine, based on formal mathematical decomposition of the indexing process. PIQUE factors out commonalities in indexing, employing algorithmic/data structure \"plugins\" to mix orthogonal indexing concepts such as FastBit compressed bitmaps with ALACRITY binning, all within one framework. Second, we define the hyperdyadic tree index, distinct from both bitmap and inverted indexes, demonstrating good index compression while maintaining high query performance. We implement the hyperdyadic tree index within PIQUE, reinforcing our unified indexing model. We conduct a performance study of the hyperdyadic tree index vs. WAH compressed bitmaps, both within PIQUE and compared to FastBit, a state-of-the-art bitmap index system. The hyperdyadic tree index shows a 1.14-1.90x storage reduction vs. compressed bitmaps, with comparable or better query performance under most scenarios tested.","PeriodicalId":225179,"journal":{"name":"Proceedings of the 27th International Conference on Scientific and Statistical Database Management","volume":"171 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114613946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Henrique O. Marques, R. Campello, A. Zimek, J. Sander
{"title":"On the internal evaluation of unsupervised outlier detection","authors":"Henrique O. Marques, R. Campello, A. Zimek, J. Sander","doi":"10.1145/2791347.2791352","DOIUrl":"https://doi.org/10.1145/2791347.2791352","url":null,"abstract":"Although there is a large and growing literature that tackles the unsupervised outlier detection problem, the unsupervised evaluation of outlier detection results is still virtually untouched in the literature. The so-called internal evaluation, based solely on the data and the assessed solutions themselves, is required if one wants to statistically validate (in absolute terms) or just compare (in relative terms) the solutions provided by different algorithms or by different parameterizations of a given algorithm in the absence of labeled data. However, in contrast to unsupervised cluster analysis, where indexes for internal evaluation and validation of clustering solutions have been conceived and shown to be very useful, in the outlier detection domain this problem has been notably overlooked. Here we discuss this problem and provide a solution for the internal evaluation of top-n (binary) outlier detection results. Specifically, we propose an index called IREOS (Internal, Relative Evaluation of Outlier Solutions) that can evaluate and compare different candidate labelings of a collection of multivariate observations in terms of outliers and inliers. We also statistically adjust IREOS for chance and extensively evaluate it in several experiments involving different collections of synthetic and real data sets.","PeriodicalId":225179,"journal":{"name":"Proceedings of the 27th International Conference on Scientific and Statistical Database Management","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122231729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Querying RDF data with text annotated graphs","authors":"Lushan Han, Timothy W. Finin, A. Joshi, D. Cheng","doi":"10.1145/2791347.2791381","DOIUrl":"https://doi.org/10.1145/2791347.2791381","url":null,"abstract":"Scientists and casual users need better ways to query RDF databases or Linked Open Data. Using the SPARQL query language requires not only mastering its syntax and semantics but also understanding the RDF data model, the ontology used, and URIs for entities of interest. Natural language query systems are a powerful approach, but current techniques are brittle in addressing the ambiguity and complexity of natural language and require expensive labor to supply the extensive domain knowledge they need. We introduce a compromise in which users give a graphical \"skeleton\" for a query and annotates it with freely chosen words, phrases and entity names. We describe a framework for interpreting these \"schema-agnostic queries\" over open domain RDF data that automatically translates them to SPARQL queries. The framework uses semantic textual similarity to find mapping candidates and uses statistical approaches to learn domain knowledge for disambiguation, thus avoiding expensive human efforts required by natural language interface systems. We demonstrate the feasibility of the approach with an implementation that performs well in an evaluation on DBpedia data.","PeriodicalId":225179,"journal":{"name":"Proceedings of the 27th International Conference on Scientific and Statistical Database Management","volume":"519 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116703614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Improving performance of similarity measures for uncertain time series using preprocessing techniques","authors":"M. Orang, Nematollaah Shiri","doi":"10.1145/2791347.2791385","DOIUrl":"https://doi.org/10.1145/2791347.2791385","url":null,"abstract":"We study the impact of preprocessing techniques on performance and effectiveness of the similarity measures for uncertain time series. Some existing work on uncertain time series use the same similarity measures developed for standard time series, to which we refer as traditional similarity measures. More recently, a number of new similarity measures have been proposed for uncertain time series, to which we refer as uncertain similarity measures. However, they have been shown not to be as effective as the traditional measures. In this work, we show that the performance of uncertain similarity measures can be improved through preprocessing techniques. We establish this through extensive experiments using the UCR benchmark data. Our results in fact indicate that the uncertain similarity measures together with preprocessing outperform the traditional similarity measures.","PeriodicalId":225179,"journal":{"name":"Proceedings of the 27th International Conference on Scientific and Statistical Database Management","volume":"9 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124665322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Emad Soroush, M. Balazinska, S. Krughoff, A. Connolly
{"title":"Efficient iterative processing in the SciDB parallel array engine","authors":"Emad Soroush, M. Balazinska, S. Krughoff, A. Connolly","doi":"10.1145/2791347.2791362","DOIUrl":"https://doi.org/10.1145/2791347.2791362","url":null,"abstract":"Many scientific data-intensive applications perform iterative computations on array data. There exist multiple engines specialized for array processing. These engines efficiently support various types of operations, but none includes native support for iterative processing. In this paper, we develop a model for iterative array computations and a series of optimizations. We evaluate the benefits of an optimized, native support for iterative array processing on the SciDB engine and real workloads from the astronomy domain.","PeriodicalId":225179,"journal":{"name":"Proceedings of the 27th International Conference on Scientific and Statistical Database Management","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131770454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"GRAPHITE: an extensible graph traversal framework for relational database management systems","authors":"M. Paradies, Wolfgang Lehner, Christof Bornhövd","doi":"10.1145/2791347.2791383","DOIUrl":"https://doi.org/10.1145/2791347.2791383","url":null,"abstract":"Graph traversals are a basic but fundamental ingredient for a variety of graph algorithms and graph-oriented queries. To achieve the best possible query performance, they need to be implemented at the core of a database management system that aims at storing, manipulating, and querying graph data. Increasingly, modern business applications demand native graph query and processing capabilities for enterprise-critical operations on data stored in relational database management systems. In this paper we propose an extensible graph traversal framework (GRAPHITE) as a central graph processing component on a common storage engine inside a relational database management system. We study the influence of the graph topology on the execution time of graph traversals and derive two traversal algorithm implementations specialized for different graph topologies and traversal queries. We conduct extensive experiments on GRAPHITE for a large variety of real-world graph data sets and input configurations. Our experiments show that the proposed traversal algorithms differ by up to two orders of magnitude for different input configurations and therefore demonstrate the need for a versatile framework to efficiently process graph traversals on a wide range of different graph topologies and types of queries. Finally, we highlight that the query performance of our traversal implementations is competitive with those of two native graph database management systems.","PeriodicalId":225179,"journal":{"name":"Proceedings of the 27th International Conference on Scientific and Statistical Database Management","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131008642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Quoc Trung Tran, I. Jimenez, Rui Wang, N. Polyzotis, A. Ailamaki
{"title":"RITA: an index-tuning advisor for replicated databases","authors":"Quoc Trung Tran, I. Jimenez, Rui Wang, N. Polyzotis, A. Ailamaki","doi":"10.1145/2791347.2791376","DOIUrl":"https://doi.org/10.1145/2791347.2791376","url":null,"abstract":"Given a replicated database, a divergent design tunes the indexes in each replica differently in order to specialize it for a specific subset of the workload. Empirical studies have shown that this specialization brings significant performance gains compared to the common practice of having the same indexes in all replicas. However, reaping the benefits of divergent designs requires the development of new tuning tools for database administrators, and the existing tools unfortunately suffer from severe shortcomings: they assume a fixed number of replicas and a known workload distribution, and ignore the possibility of replica failures and the subsequent effect on load imbalance. To address these shortcomings, we analyze the theory and practice of tuning the divergent design of a replicated database. We design and implement RITA, a novel divergent-tuning advisor that offers several essential features not found in existing tools: (1) it generates robust divergent designs that allow the system to adapt gracefully to replica failures; (2) it computes designs that spread the load evenly among specialized replicas, both during normal operation and when replicas fail; (3) it monitors the workload online in order to detect changes that require a recomputation of the divergent design; and, (4) it offers suggestions to elastically reconfigure the system (by adding/removing replicas or adding/dropping indexes) to respond to workload changes. The key technical innovation in this paper is the formulation the problem of selecting an optimal design as a Binary Integer Program (BIP). The BIP has a relatively small number of variables, thereby enabling an efficient solution using any off-the-shelf linear-optimization software. Experimental results demonstrate that RITA improves on the performance of the computed designs of existing tools by a factor of up to three, and at the same time has a low runtime overhead that enables fast tuning sessions.","PeriodicalId":225179,"journal":{"name":"Proceedings of the 27th International Conference on Scientific and Statistical Database Management","volume":"20 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120874374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Proceedings of the 27th International Conference on Scientific and Statistical Database Management","authors":"","doi":"10.1145/2791347","DOIUrl":"https://doi.org/10.1145/2791347","url":null,"abstract":"","PeriodicalId":225179,"journal":{"name":"Proceedings of the 27th International Conference on Scientific and Statistical Database Management","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122700369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}