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Query indexing with containment-encoded intervals for efficient stream processing

Kun-Lung Wu, Shyh-Kwei Chen, Philip S. Yu
2005 Knowledge and Information Systems  
To efficiently evaluate continual queries against a stream, a main memory-based query index with a small storage cost and a fast search time is needed, especially if the stream is rapid.  ...  The interval query index is preferably main memory-based and it must have two important properties: low storage cost and excellent search performance.  ...  Table 2 : 2 Comparison of query decomposition for VC-based query indexes.  ... 
doi:10.1007/s10115-005-0202-0 fatcat:bz3a57fr4zblhlzmftavlqpfiy

Design and evaluation of signature file organization incorporating vertical and horizontal decomposition schemes [chapter]

Hiroyuki Kitagawa, Noriyasu Watanabe, Yoshiharu Ishikawa
1996 Lecture Notes in Computer Science  
P-FSSF incorporates both vertical and horizontal decomposition schemes to reduce page accesses required to look up signatures.  ...  We develop formulas to estimate the retrieval cost of P-FSSF in the context of the general set-valued object retrieval. Also, formulas to tell the update and storage costs are derived.  ...  , and the other is the Key-Based Bit-Sliced Signature File [?] . The former combines the Frame-Slice-based vertical decomposition and the horizontal decomposition using the extendible hashing.  ... 
doi:10.1007/bfb0034739 fatcat:mtfdeuitwvfzpn3rtrn7vhoqc4

Cost-Based Query Optimization in Centralized Relational Databases

Nawaraj Paudel, Jagdish Bhatta
2019 Journal of Institute of Science and Technology  
Cost-based query optimization compares different strategies based on relative costs (amount of time that the query needs to run) and selects and executes one that minimizes the cost.  ...  The cost of a strategy is just an estimate based on how many estimated CPU and I/O resources that the query will use.  ...  executing a SQL statement based on overall cost of the query.  ... 
doi:10.3126/jist.v24i1.24627 fatcat:krutrycy3vekfaxqvwctt37so4

From Hypertree Width to Submodular Width and Data-dependent Structural Decompositions

Francesco Scarcello
2018 Sistemi Evoluti per Basi di Dati  
Recent advances in structural decomposition methods provide an important answer regarding the fixed-parameter tractability of conjunctive queries, and efficient algorithms based on decomposition methods  ...  Identifying the frontier of tractability for conjunctive queries is a longstanding question in database theory.  ...  Given a query Q and a hypertree decomposition HD for the query hypergraph H Q , the query can be transformed into an acyclic query, based on the decomposition HD .  ... 
dblp:conf/sebd/Scarcello18 fatcat:hnq23laq7jejhotv6e5fwiifxq

Federated SPARQL Query Processing over Heterogeneous Linked Data Fragments

Lars Heling, Maribel Acosta
2022 Proceedings of the ACM Web Conference 2022  
Linked Data Fragments (LDFs) are Web interfaces that enable querying knowledge graphs on the Web.  ...  In this work, we address the challenges of SPARQL query processing over federations with heterogeneous LDF interfaces.  ...  Query Decomposition. We propose a query decomposition approach that can be combined with a heuristic-based source pruning method.  ... 
doi:10.1145/3485447.3511947 fatcat:a2hntgdut5gh5khlvkjzcnd6ra

Efficient Scale-Out Using Query-Driven Workload Distribution and Fragment Allocation

Stefan Halfpap
2019 Very Large Data Bases Conference  
To address large-size problems, we developed a novel decomposition-based heuristic using linear programming.  ...  We compare our approach with a rule-based stateof-the-art allocation algorithm using a real-world workload comprising thousands of queries.  ...  Reallocation Costs Workloads (including query costs) or fragment sizes may change.  ... 
dblp:conf/vldb/Halfpap19 fatcat:c5cm3ci4vzdmhmjitdcaletfze

Query answering exploiting structural properties

Francesco Scarcello
2005 SIGMOD record  
In particular, we describe how this notion may be used for identifying tractable classes of database queries and answering such queries in an efficient way.  ...  Acknowledgments The author sincerely thanks Georg Gottlob and Nicola Leone, who worked with him on these issues since 1999, when they jointly defined the notion of hypertree decompositions.  ...  For all commercial DBMSs, such a way is always based on quantitative methods: they examine a number of alternative plans for answering a query and then choose the best one, according to some cost model  ... 
doi:10.1145/1084805.1084827 fatcat:enicq2ngqrbinnr2lkohxxzc7y

A Framework for Federated SPARQL Query Processing over Heterogeneous Linked Data Fragments [article]

Lars Heling, Maribel Acosta
2021 arXiv   pre-print
The framework comprises query decomposition, query planning, and physical operators adapted to the particularities of different LDF interfaces.  ...  Client-side query processing approaches have been proposed and are tailored to evaluate queries over individual interfaces.  ...  For both tasks, common cost-based query planners leverage statistics on the data of the members in the federation.  ... 
arXiv:2102.03269v2 fatcat:34ksvam5e5dwnpk7mqjaszjvcy

Object-relational management of complex geographical objects

Hans-Peter Kriegel, Peter Kunath, Martin Pfeifle, Matthias Renz
2004 Proceedings of the 12th annual ACM international workshop on Geographic information systems - GIS '04  
These gray intervals are created by using a cost-based decompositioning algorithm which takes the access probability and the decompression cost of them into account.  ...  Furthermore, we exploit statistical information of the database objects to find a cost-optimal decomposition of the query objects.  ...  Furthermore, we introduced a cost-based decompositioning algorithm for complex rasterized objects, called GroupObj.  ... 
doi:10.1145/1032222.1032240 dblp:conf/gis/KriegelKPR04 fatcat:i2kxqis3gra45m7jakpknjm4du

Workload Representation across Different Storage Architectures for Relational DBMS

Andreas Lübcke, Veit Köppen, Gunter Saake
2011 Workshop Grundlagen von Datenbanken  
Our approach also supports fine granular workload analyses based on database operations. 23 rd GI-Workshop on Foundations of Databases (Grundlagen von Datenbanken),  ...  QUERY DECOMPOSITION In this section, we introduce the query decomposition approach.  ...  Query Plans A workload decomposition based on database operations is necessary to select the optimal storage architecture (cf. [16] ).  ... 
dblp:conf/gvd/LubckeKS11 fatcat:wdu5gdqwong5ndlz6ek5kmsxfi

Statistic Driven Acceleration of Object-Relational Space-Partitioning Index Structures [chapter]

Hans-Peter Kriegel, Peter Kunath, Martin Pfeifle, Matthias Renz
2004 Lecture Notes in Computer Science  
Furthermore, there exist effective and efficient models to estimate the selectivity and the I/O cost in order to guide the cost-based optimizer whether and how to include these index structures into the  ...  Relational index structures, as for instance the Relational Interval Tree or the Linear Quadtree, support efficient processing of queries on top of existing object-relational database systems.  ...  To sum up, our statistic-based decomposition approach is especially useful for commonly used box volume queries.  ... 
doi:10.1007/978-3-540-24571-1_14 fatcat:whapuq5375b7zgat2zrgu6d4oe

Wavelet-Based Cost Estimation for Spatial Queries [chapter]

Min Wang, Jeffrey Scott Vitter, Lipyeow Lim, Sriram Padmanabhan
2001 Lecture Notes in Computer Science  
We i n troduce a new method that provides accurate cost estimation for spatial selections, or window queries, by building wavelet-based histograms for spatial data.  ...  Query cost estimation is an important and well-studied problem in relational database systems. In this paper we study the cost estimation problem in the context of spatial database systems.  ...  During online phase, the cost of a given query is estimated based upon the relevant catalog information.  ... 
doi:10.1007/3-540-47724-1_10 fatcat:zhdxbdajurbobo7p3j53a6erbi

AniPQO [chapter]

Arvind Hulgeri, S. Sudarshan
2003 Proceedings 2003 VLDB Conference  
The cost of a query plan depends on many parameters, such as predicate selectivities and available memory, whose values may not be known at optimization time.  ...  Parametric query optimization (PQO) optimizes a query into a number of candidate plans, each optimal for some region of the parameter space.  ...  We are grateful to Prasan Roy for providing the code for the Volcano-based conventional optimizer.  ... 
doi:10.1016/b978-012722442-8/50073-2 dblp:conf/vldb/HulgeriS03 fatcat:gpp62dlpsfgsnjie7evy52np5i

An approach to managing the execution of large SQL queries

Yabin Meng, Paul Bird, Pat Martin, Wendy Powley
2007 CASCON '07: Proceedings of the 2007 conference of the center for advanced studies on Collaborative research  
In this thesis, we present an approach to managing the execution of large queries that involves the decomposition of large queries into an equivalent set of smaller queries and then scheduling the smaller  ...  queries so that the work is accomplished with less impact on other queries.  ...  The first contribution is an original method of breaking up a large query into smaller queries based on its access plan structure and the estimated query cost information.  ... 
doi:10.1145/1321211.1321245 dblp:conf/cascon/MengBMP07 fatcat:2wpqgr4olfhn7jjsjjbuv3xzo4

Energy-efficient data organization and query processing in sensor networks

Ramakrishna Gummadi, Xin Li, Ramesh Govindan, Cyrus Shahabi, Wei Hong
2005 ACM SIGBED Review  
These distributed indexes offer a rich design space of a) logical decompositions of sensor relation schema into indexes, as well as b) physical mappings of these indexes onto sensors.  ...  multi-dimensional range and range-aggregate queries.  ...  We found that, in many cases, fully decomposing the base relation per-forms better than zero or any partial decomposition, even if the decomposition is carried out with an eye toward a given query workload  ... 
doi:10.1145/1121782.1121785 fatcat:elubnyefirahxm5ru77sca44ki
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