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(Almost) Optimal parallel block access for range queries

Mikhail J. Atallah, Sunil Prabhakar
2003 Information Sciences  
Given k disks, a query that accesses m blocks, the optimal number of parallel block accesses that is theoretically possible is OPT = rmjkl Though several schemes for the allocation of tiles to disks have  ...  We establish that any range query on a 2 q x 2 Q -block grid of blocks can be performed using k = 2 L disks (t~q), in at most OPT + 0(1) parallel block accesses.  ...  The goal of the allocation is to achieve optimal parallel access for each range query.  ... 
doi:10.1016/s0020-0255(03)00181-6 fatcat:ezn4k5sjonhkzfa63kbrdm4eqe

Almost fully-parallel parentheses matching

Omer Berkman, Uzi Vishkin
1995 Discrete Applied Mathematics  
Suppose we are given a balanced sequence of parentheses and wish to find for each parenthesis its mate.  ...  Assuming the levels of nesting of each parenthesis are given, we present an algorithm that runs in O(a(n)) time using an optimal number of processors (where a(n) is the inverse of Ackermann's function)  ...  The algorithm, presented in Section 4, is almost fully-parallel. Corollary 2.1. There exists an almost filly-parallel algorithm for the parentheses matching problem. ).  ... 
doi:10.1016/0166-218x(93)e0137-n fatcat:bym4uqbu2vc7bmxrlfrjz442ym

Efficiently making (almost) any concurrency control mechanism serializable

Tianzheng Wang, Ryan Johnson, Alan Fekete, Ippokratis Pandis
2017 The VLDB journal  
The dependency tracking and validation tests can be done efficiently, fully parallel and latch-free, for multi-version systems on modern hardware with substantial core count and large main memory.  ...  The underlying CC retains control of scheduling and transactional accesses, while SSN tracks the resulting dependencies.  ...  Acknowledgments The authors gratefully acknowledge Goetz Graefe and Harumi Kuno for their invaluable suggestions and input they provided during the development of SSN, as well as Kangnyeon Kim for his  ... 
doi:10.1007/s00778-017-0463-8 fatcat:eh7bggnm6bajtnjdyj5hkf2f4a

An Active Learning Algorithm for Ranking from Pairwise Preferences with an Almost Optimal Query Complexity [article]

Nir Ailon
2011 arXiv   pre-print
We present an active learning algorithm for this problem, with query bounds significantly beating general (non active) bounds for the same error guarantee, while almost achieving the information theoretical  ...  The decomposition is done by adapting a recent result by Kenyon and Schudy for a related combinatorial optimization problem to the query efficient setting.  ...  among big blocks (local chaos), yet possible to rank almost optimally while respecting the decomposition (approximate optimality).  ... 
arXiv:1011.0108v11 fatcat:of27iv6di5bl5p5fqtewfqodvu

Symmetry, Almost

Amanda Folsom
2019 Notices of the American Mathematical Society  
The AMS is not responsible for rate changes or for the quality of the accommodations. Hotels have varying cancellation and early checkout penalties; be sure to ask for details.  ...  For the latest information, see  ...  For a new query point, this information will be compared to the same information for all training data, and then a label that best matches the new query point will be assigned.  ... 
doi:10.1090/noti1775 fatcat:xwrijzvqazg7bdym7un5qq2jjq

Encryption Modes with Almost Free Message Integrity

Charanjit S. Jutla
2008 Journal of Cryptology  
For comparison, the well known CBC (cipher block chaining) encryption mode requires m block cipher evaluations, and the second pass of computing the CBC-MAC essentially requires additional m + 1 block  ...  We define a new mode of operation for block ciphers which in addition to providing confidentiality also ensures message integrity.  ...  Rao, Ron Rivest, Phil Rogaway, referees of Eurocrypt 2001, and reviewers of this journal for helpful suggestions. Finally, the author thanks Pau-Chen Cheng for introducing him to the problem.  ... 
doi:10.1007/s00145-008-9024-z fatcat:h5a5ynsennba5lca7e2qiwnhzm

(Almost) All of Entity Resolution [article]

Olivier Binette, Rebecca C. Steorts
2022 arXiv   pre-print
Supplementary Materials Please refer to Supplementary Materials for “(Almost) All of Entity Resolution” to access the following contents.  ...  First, they use blocking where, in each block, they calculated comparison vectors for each record pair.  ... 
arXiv:2008.04443v3 fatcat:6tunuro7afhmbpambcn2bk32ly

Almost optimal accessing of nonstochastic channels in cognitive radio networks

Xiang-Yang Li, PanLong Yang, Yubo Yan, LiZhao You, Shaojie Tang, QiuYuan Huang
2012 2012 Proceedings IEEE INFOCOM  
Our experiments show that our schemes achieve almost optimal throughput compared with an optimal static strategy, and perform significantly better than previous methods in many settings.  ...  We propose joint channel sensing, probing, and accessing schemes for secondary users in cognitive radio networks.  ...  We investigate a joint sensing/probing/accessing mechanism that will result in (almost) optimal expected throughput, compared with the optimal fixedchannel strategy.  ... 
doi:10.1109/infcom.2012.6195616 dblp:conf/infocom/LiYYYTH12 fatcat:fxg7jgf6ozhdlkqcay7pddb7di

Parallel I/O aware query optimization

Pedram Ghodsnia, Ivan T. Bowman, Anisoara Nica
2014 Proceedings of the 2014 ACM SIGMOD international conference on Management of data - SIGMOD '14  
In this paper, at first, we show why the query optimizer needs to be aware of the benefit of the I/O parallelism in solid state drives.  ...  Although the impact of using SSD in query processing has been studied in the past, exploiting the I/O parallelism of SSDs in query processing and optimization has not received enough attention.  ...  optimizer choice for the best access method is affected by the exploitation of the parallel I/O by the IS, FTS, PIS, and PFTS access methods.  ... 
doi:10.1145/2588555.2595635 dblp:conf/sigmod/GhodsniaBN14 fatcat:3guxfut5mjdqflhunfwtye7xmy


Yu Su, Yi Wang, Gagan Agrawal, Rajkumar Kettimuthu
2013 Proceedings of the International Conference for High Performance Computing, Networking, Storage and Analysis on - SC '13  
A number of optimizations, like parallel indexing, performance model for data subsetting, and parallel streaming are also applied.  ...  Different queries types (query over dimensions, coordinates and values) are supported by our tool.  ...  For data blocks that do not contain any data subset element, parallel indexing can help us skip these blocks.  ... 
doi:10.1145/2503210.2503270 dblp:conf/sc/SuWAK13 fatcat:4l7ksqgjbvgj3opsklmfxg7rlq

Declustering Two-Dimensional Datasets over MEMS-Based Storage [chapter]

Hailing Yu, Divyakant Agrawal, Amr El Abbadi
2004 Lecture Notes in Computer Science  
However, prior optimal cost and data placement approaches for processing range queries over two-dimensional datasets do not consider this property.  ...  In this paper, we reevaluate the optimal cost of range queries, and prove that, in general, it is impossible to achieve the new optimal cost.  ...  Based on this observation, we reevaluate the optimal cost of range queries for hard disks.  ... 
doi:10.1007/978-3-540-24741-8_29 fatcat:nrmmnw2fpzanneetsofphv75bm

A Performance Study of Traversing Spatial Indexing Structures in Parallel on GPU

Jinwoong Kim, Sumin Hong, Beomseok Nam
2012 2012 IEEE 14th International Conference on High Performance Computing and Communication & 2012 IEEE 9th International Conference on Embedded Software and Systems  
Inherently spatial indexing structures such as R-Trees are not well suited for CUDA environment due to its irregular tree traversal for range queries.  ...  Also, we propose a new range query search algorithmthree-phasesearch that avoids non-sequential random access to tree nodes and accelerates the search performance of spatial indexing structures on GPU.  ...  range query.  ... 
doi:10.1109/hpcc.2012.121 dblp:conf/hpcc/KimHN12 fatcat:3ualbrisrzhsliyh2xpzfmz2za

Distributed architecture of Oracle database in-memory

Niloy Mukherjee, Kartik Kulkarni, Tirthankar Lahiri, Juan Loaiza, Neil Macnaughton, Vineet Marwah, Atrayee Mullick, Andy Witkowski, Jiaqi Yan, Mohamed Zait, Shasank Chavan, Maria Colgan (+6 others)
2015 Proceedings of the VLDB Endowment  
The data processing challenges combined with the rapid advancement of hardware systems has necessitated the evolution of a new breed of main-memory databases optimized for mixed OLTAP environments and  ...  In parallel, computer hardware systems are scaling out elastically, scaling up in the number of processors and cores, and increasing main memory capacity extensively.  ...  We also thank Niraj Srivastava, Linan Jiang, and Indira Patil for helping us with performance evaluation of the architecture.  ... 
doi:10.14778/2824032.2824061 fatcat:4szpiajq65g3xd5rzgyjj3on5m

Parallel accelerated isocontouring for out-of-core visualization

C. L. Bajaj, V. Pascucci, D. Thompson, X. Y. Zhang
1999 Proceedings of the 1999 IEEE symposium on Parallel visualization and graphics - PVGS '99  
minimal access to secondary memory in out-of-core computations.  ...  In this paper we introduce a scheme for static analysis that allows us to partition large geometric datasets at multiple levels of granularity to achieve both load balancing in parallel computations and  ...  With a good partition all cells of one range may fit into the primary memory of parallel computer so that multiple queries within such range can be processed without extra accesses to disk.  ... 
doi:10.1145/328712.319342 fatcat:jl45z4kynzczhfcq6recg3arcy

Dynamic allocation of Signature Files on Parallel devices

Man-Kwan Shan, Suh-Yin Lee
1998 Information Systems  
Signature file is one of the efficient access methods for retrieval of text database. In a large database server, parallel device is utilized to achieve concurrent access.  ...  Efficient allocation of signature file on parallel device minimizes the query response time and is important in the design of large databases.  ...  Acknowledgements -We thank the anonymous referees for their valuable comments and suggestions. 111  ... 
doi:10.1016/s0306-4379(98)00024-6 fatcat:o6xtuzh2tbhb3igsv76rtxseyy
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