Proceedings of the ... ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems. ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems最新文献

{"title":"Mergeable summaries","authors":"P. Agarwal, Graham Cormode, Zengfeng Huang, J. M. Phillips, Zhewei Wei, K. Yi","doi":"10.1145/2213556.2213562","DOIUrl":"https://doi.org/10.1145/2213556.2213562","url":null,"abstract":"We study the mergeability of data summaries. Informally speaking, mergeability requires that, given two summaries on two data sets, there is a way to merge the two summaries into a single summary on the union of the two data sets, while preserving the error and size guarantees. This property means that the summaries can be merged in a way like other algebraic operators such as sum and max, which is especially useful for computing summaries on massive distributed data. Several data summaries are trivially mergeable by construction, most notably all the sketches that are linear functions of the data sets. But some other fundamental ones like those for heavy hitters and quantiles, are not (known to be) mergeable. In this paper, we demonstrate that these summaries are indeed mergeable or can be made mergeable after appropriate modifications. Specifically, we show that for ε-approximate heavy hitters, there is a deterministic mergeable summary of size O(1/ε) for ε-approximate quantiles, there is a deterministic summary of size O(1 over ε log(εn))that has a restricted form of mergeability, and a randomized one of size O(1 over ε log 3/21 over ε) with full mergeability. We also extend our results to geometric summaries such as ε-approximations and εkernels.\u0000 We also achieve two results of independent interest: (1) we provide the best known randomized streaming bound for ε-approximate quantiles that depends only on ε, of size O(1 over ε log 3/21 over ε, and (2) we demonstrate that the MG and the SpaceSaving summaries for heavy hitters are isomorphic.","PeriodicalId":92118,"journal":{"name":"Proceedings of the ... ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems. ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems","volume":"39 1","pages":"23-34"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73573371","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":"Dynamic top-k range reporting in external memory","authors":"Cheng Sheng, Yufei Tao","doi":"10.1145/2213556.2213576","DOIUrl":"https://doi.org/10.1145/2213556.2213576","url":null,"abstract":"In the <i>top-K range reporting</i> problem, the dataset contains <i>N</i> points in the real domain ℜ, each of which is associated with a real-valued <i>score</i>. Given an interval <i>x</i>₁,<i>x</i>₂ in ℜ and an integer <i>K</i>≤ <i>N</i>, a query returns the <i>K</i> points in <i>x</i>₁,<i>x</i>₂ having the smallest scores. We want to store the dataset in a structure so that queries can be answered efficiently. In the external memory model, the state of the art is a static structure that consumes <i>O</i>(<i>N/B</i>) space, answers a query in <i>O</i>(log<i>_B N</i> + <i>K/B</i>) time, and can be constructed in <i>O</i>(<i>N</i> + (<i>N</i> log <i>N / B</i>) log <i>_M/B</i> (<i>N/B</i>)) time, where <i>B</i> is the size of a disk block, and <i>M</i> the size of memory. We present a fully-dynamic structure that retains the same space and query bounds, and can be updated in <i>O</i>(log<i>²_B N</i>) amortized time per insertion and deletion. Our structure can be constructed in <i>O</i>((<i>N/B</i>) log <i>_M/B</i> (N/B)) time.","PeriodicalId":92118,"journal":{"name":"Proceedings of the ... ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems. ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems","volume":"20 1","pages":"121-130"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85385576","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":"The ACM PODS Alberto O. Mendelzon test-of-time award 2012","authors":"R. Hull, Phokion G. Kolaitis, D. V. Gucht","doi":"10.1145/2213556.2213564","DOIUrl":"https://doi.org/10.1145/2213556.2213564","url":null,"abstract":"In 2007, the PODS Executive Committee decided to establish a Test-of-Time Award, named after the late Alberto O. Mendelzon, in recognition of his scientific legacy, and his service and dedication to the database community. Mendelzon was an international leader in database theory, whose pioneering and fundamental work has inspired and influenced both database theoreticians and practitioners, and continues to be applied in a variety of advanced settings. He served the database community in many ways; in particular, he served as the General Chair of the PODS conference, and was instrumental in bringing together the PODS and SIGMOD conferences. He also was an outstanding educator, who guided the research of numerous doctoral students and postdoctoral fellows. The Award is to be awarded each year to a paper or a small number of papers published in the PODS proceedings ten years prior, that had the most impact (in terms of research, methodology, or transfer to practice) over the intervening decade. The decision was approved by SIGMOD and the ACM. The funds for the Award were contributed by IBM Toronto. The paper deals with a central problem in database research, namely finding classes of conjunctive queries for which problems, such as the evaluation of Boolean queries and query containment, are in polynomial time. This problem has attracted a lot of attention since the pioneering work of Yanakakis on acyclic queries. The paper shows that the earlier notion of bounded query width (introduced by Chekuri and Rajaraman in ICDT 97) is NP-hard, introduces the notion of bounded hypertree width, then shows that this notion properly generalizes earlier notions of acyclicity, that constant hypertree width is efficiently recognizable, and that Boolean queries with constant hypertree width can be efficiently evaluated. The results of the paper are applicable to both conjunctive query evaluation and to constraint satisfaction. The paper is extensively cited in the literature, and had an impact on subsequent research on these two problems. Hence, the committee has found it to be worthy of the Award.","PeriodicalId":92118,"journal":{"name":"Proceedings of the ... ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems. ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems","volume":"48 1","pages":"35-36"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75122399","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":"A dichotomy in the complexity of deletion propagation with functional dependencies","authors":"B. Kimelfeld","doi":"10.1145/2213556.2213584","DOIUrl":"https://doi.org/10.1145/2213556.2213584","url":null,"abstract":"A classical variant of the view-update problem is deletion propagation, where tuples from the database are deleted in order to realize a desired deletion of a tuple from the view. This operation may cause a (sometimes necessary) side effect---deletion of additional tuples from the view, besides the intentionally deleted one. The goal is to propagate deletion so as to maximize the number of tuples that remain in the view. In this paper, a view is defined by a self-join-free conjunctive query (sjf-CQ) over a schema with functional dependencies. A condition is formulated on the schema and view definition at hand, and the following dichotomy in complexity is established. If the condition is met, then deletion propagation is solvable in polynomial time by an extremely simple algorithm (very similar to the one observed by Buneman et al.). If the condition is violated, then the problem is NP-hard, and it is even hard to realize an approximation ratio that is better than some constant; moreover, deciding whether there is a side-effect-free solution is NP-complete. This result generalizes a recent result by Kimelfeld et al., who ignore functional dependencies. For the class of sjf-CQs, it also generalizes a result by Cong et al., stating that deletion propagation is in polynomial time if keys are preserved by the view.","PeriodicalId":92118,"journal":{"name":"Proceedings of the ... ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems. ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems","volume":"408 1","pages":"191-202"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76324923","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":"Graph sketches: sparsification, spanners, and subgraphs","authors":"K. Ahn, S. Guha, A. Mcgregor","doi":"10.1145/2213556.2213560","DOIUrl":"https://doi.org/10.1145/2213556.2213560","url":null,"abstract":"When processing massive data sets, a core task is to construct synopses of the data. To be useful, a synopsis data structure should be easy to construct while also yielding good approximations of the relevant properties of the data set. A particularly useful class of synopses are sketches, i.e., those based on linear projections of the data. These are applicable in many models including various parallel, stream, and compressed sensing settings. A rich body of analytic and empirical work exists for sketching numerical data such as the frequencies of a set of entities. Our work investigates graph sketching where the graphs of interest encode the relationships between these entities. The main challenge is to capture this richer structure and build the necessary synopses with only linear measurements.\u0000 In this paper we consider properties of graphs including the size of the cuts, the distances between nodes, and the prevalence of dense sub-graphs. Our main result is a sketch-based sparsifier construction: we show that Õ(nε-2) random linear projections of a graph on n nodes suffice to (1+ε) approximate all cut values. Similarly, we show that Õ(ε-2) linear projections suffice for (additively) approximating the fraction of induced sub-graphs that match a given pattern such as a small clique. Finally, for distance estimation we present sketch-based spanner constructions. In this last result the sketches are adaptive, i.e., the linear projections are performed in a small number of batches where each projection may be chosen dependent on the outcome of earlier sketches. All of the above results immediately give rise to data stream algorithms that also apply to dynamic graph streams where edges are both inserted and deleted. The non-adaptive sketches, such as those for sparsification and subgraphs, give us single-pass algorithms for distributed data streams with insertion and deletions. The adaptive sketches can be used to analyze MapReduce algorithms that use a small number of rounds.","PeriodicalId":92118,"journal":{"name":"Proceedings of the ... ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems. ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems","volume":"16 1","pages":"5-14"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77111014","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":"Classification of annotation semirings over query containment","authors":"Egor V. Kostylev, Juan L. Reutter, András Z. Salamon","doi":"10.1145/2213556.2213590","DOIUrl":"https://doi.org/10.1145/2213556.2213590","url":null,"abstract":"We study the problem of query containment of (unions of) conjunctive queries over annotated databases. Annotations are typically attached to tuples and represent metadata such as probability, multiplicity, comments, or provenance. It is usually assumed that annotations are drawn from a commutative semiring. Such databases pose new challenges in query optimization, since many related fundamental tasks, such as query containment, have to be reconsidered in the presence of propagation of annotations.\u0000 We axiomatize several classes of semirings for each of which containment of conjunctive queries is equivalent to existence of a particular type of homomorphism. For each of these types we also specify all semirings for which existence of a corresponding homomorphism is a sufficient (or necessary) condition for the containment. We exploit these techniques to develop new decision procedures for containment of unions of conjunctive queries and axiomatize corresponding classes of semirings. This generalizes previous approaches and allows us to improve known complexity bounds.","PeriodicalId":92118,"journal":{"name":"Proceedings of the ... ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems. ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems","volume":"46 1","pages":"237-248"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90204528","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":"A rigorous and customizable framework for privacy","authors":"Daniel Kifer, Ashwin Machanavajjhala","doi":"10.1145/2213556.2213571","DOIUrl":"https://doi.org/10.1145/2213556.2213571","url":null,"abstract":"In this paper we introduce a new and general privacy framework called Pufferfish. The Pufferfish framework can be used to create new privacy definitions that are customized to the needs of a given application. The goal of Pufferfish is to allow experts in an application domain, who frequently do not have expertise in privacy, to develop rigorous privacy definitions for their data sharing needs. In addition to this, the Pufferfish framework can also be used to study existing privacy definitions.\u0000 We illustrate the benefits with several applications of this privacy framework: we use it to formalize and prove the statement that differential privacy assumes independence between records, we use it to define and study the notion of composition in a broader context than before, we show how to apply it to protect unbounded continuous attributes and aggregate information, and we show how to use it to rigorously account for prior data releases.","PeriodicalId":92118,"journal":{"name":"Proceedings of the ... ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems. ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems","volume":"46 1","pages":"77-88"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83237278","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":"Nearest-neighbor searching under uncertainty","authors":"P. Agarwal, A. Efrat, Swaminathan Sankararaman, Wuzhou Zhang","doi":"10.1145/2213556.2213588","DOIUrl":"https://doi.org/10.1145/2213556.2213588","url":null,"abstract":"Nearest-neighbor queries, which ask for returning the nearest neighbor of a query point in a set of points, are important and widely studied in many fields because of a wide range of applications. In many of these applications, such as sensor databases, location based services, face recognition, and mobile data, the location of data is imprecise. We therefore study nearest neighbor queries in a probabilistic framework in which the location of each input point and/or query point is specified as a probability density function and the goal is to return the point that minimizes the expected distance, which we refer to as the expected nearest neighbor (ENN). We present methods for computing an exact ENN or an ε-approximate ENN, for a given error parameter 0 < ε 0 < 1, under different distance functions. These methods build an index of near-linear size and answer ENN queries in polylogarithmic or sublinear time, depending on the underlying function. As far as we know, these are the first nontrivial methods for answering exact or ε-approximate ENN queries with provable performance guarantees.","PeriodicalId":92118,"journal":{"name":"Proceedings of the ... ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems. ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems","volume":"61 1 1","pages":"225-236"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83427827","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":"On the optimality of clustering properties of space filling curves","authors":"Pan Xu, S. Tirthapura","doi":"10.1145/2213556.2213587","DOIUrl":"https://doi.org/10.1145/2213556.2213587","url":null,"abstract":"Space filling curves have for long been used in the design of data structures for multidimensional data. A fundamental quality metric of a space filling curve is its \"clustering number\" with respect to a class of queries, which is the average number of contiguous segments on the space filling curve that a query region can be partitioned into. We present a characterization of the clustering number of a general class of space filling curves, as well as the first non-trivial lower bounds on the clustering number for any space filling curve. Our results also answer an open problem that was posed by Jagadish in 1997.","PeriodicalId":92118,"journal":{"name":"Proceedings of the ... ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems. ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems","volume":"7 1","pages":"215-224"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76452089","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":"Linguistic foundations for bidirectional transformations: invited tutorial","authors":"B. Pierce","doi":"10.1145/2213556.2213568","DOIUrl":"https://doi.org/10.1145/2213556.2213568","url":null,"abstract":"Computing is full of situations where two different structures must be \"connected\" in such a way that updates to each can be propagated to the other. This is a generalization of the classical view update problem, which has been studied for decades in the database community [11, 2, 22]; more recently, related problems have attracted considerable interest in other areas, including programming languages [42, 28, 34, 39, 4, 7, 33, 16, 1, 37, 35, 47, 49] software model transformation [43, 50, 44, 45, 12, 13, 14, 24, 25, 10, 51], user interfaces [38] and system configuration [36]. See [18, 17, 10, 30] for recent surveys.\u0000 Among the fruits of this cross-pollination has been the development of a linguistic perspective on the problem. Rather than taking some view definition language as fixed (e.g., choosing some subset of relational algebra) and looking for tractable ways of \"inverting\" view definitions to propagate updates from view to source [9], we can directly design new bidirectional programming languages in which every expression defines a pair of functions mapping updates on one structure to updates on the other. Such structures are often called lenses [18].\u0000 The foundational theory of lenses has been studied extensively [20, 47, 26, 32, 48, 40, 15, 31, 46, 41, 21, 27], and lens-based language designs have been developed in several domains, including strings [5, 19, 3, 36], trees [18, 28, 39, 35, 29], relations [6], graphs [23], and software models [43, 50, 44, 12, 13, 14, 24, 25, 8]. These languages share some common elements with modern functional languages---in particular, they come with very expressive type systems. In other respects, they are rather novel and surprising.\u0000 This tutorial surveys recent developments in the theory of lenses and the practice of bidirectional programming languages.","PeriodicalId":92118,"journal":{"name":"Proceedings of the ... ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems. ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems","volume":"37 1","pages":"61-64"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84746743","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}