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Equivalence of views by query capacity

Tim Connors
1986 Journal of computer and system sciences (Print)  
Ultimately, the capability of a view is determined by the set of all view queries.  ...  In addition, we introduce the notions of query capacity and view equivalence.  ...  Equivalence of Views by Query Capacity We now turn our attention to the central concepts of this paper, namely query capacity and equivalence of views.  ... 
doi:10.1016/0022-0000(86)90020-6 fatcat:6irgbhottrh23fzdyrylhnidye

Equivalence of views by query capacity

Tim Connors
1985 Proceedings of the fourth ACM SIGACT-SIGMOD symposium on Principles of database systems - PODS '85  
Ultimately, the capability of a view is determined by the set of all view queries.  ...  In addition, we introduce the notions of query capacity and view equivalence.  ...  Equivalence of Views by Query Capacity We now turn our attention to the central concepts of this paper, namely query capacity and equivalence of views.  ... 
doi:10.1145/325405.325422 dblp:conf/pods/Connors85 fatcat:cb23hg6qafcqbhmxsjc7kheazm

Schema and Data Translation

P. Atzeni
2006 22nd International Conference on Data Engineering (ICDE'06)  
Atzeni, ER 2005 Tutorial on "Schema and data translation" Total updatable view • G1: querying via S1 the data handled by S2 (a view) + viewing the whole db of S2 through S1 + updating the db of S2 through  ...  S1 the data handled by S2 (a view) • G2: G1 + viewing the whole db of S2 through S1 • G3: G2 + updating the db of S2 through S1 • G4: querying S2 via S1 and S1 via S2 S1 q f S2 P.  ... 
doi:10.1109/icde.2006.134 dblp:conf/icde/Atzeni06 fatcat:2povbmyzmjafviapev3m3cuh2i

Page 1051 of Mathematical Reviews Vol. , Issue 88b [page]

1988 Mathematical Reviews  
Richard Hull (Los Angeles, Calif.) 88b:68023 68P15 Connors, Tim (1-HPL) Equivalence of views by query capacity.  ...  A measure of this ability, called “query capac- ity”, is introduced and shown to be valuable for defining impor- tant concepts concerning views.  ... 

View Selection under Multiple Resource Constraints in a Distributed Context [chapter]

Imene Mami, Zohra Bellahsene, Remi Coletta
2012 Lecture Notes in Computer Science  
The use of materialized views in commercial database systems and data warehousing systems is a common technique to improve the query performance.  ...  Finally, we experimentally show that our approach provides better performance resulting from evaluating the quality of the solutions in terms of cost saving.  ...  The total query cost is computed by summing over the cost of processing each input query rewritten over the materialized views.  ... 
doi:10.1007/978-3-642-32597-7_25 fatcat:77p6xjdn4fdetm2tiyjz4fuubm

Page 62 of Library & Information Science Abstracts Vol. , Issue 8 [page]

1994 Library & Information Science Abstracts  
Several tests were developed that each serve as sufficient conditions for information capacity equivalence or dominance. Each test is characterized by a set of schema transformations.  ...  This undecidability suggests that in addition to the overly liberal nature of information capacity equivalence alternative, more restrictive notions of equivalence that can be effectively tested should  ... 

Reduced Quotient Cube: Maximize Query Answering Capacity in OLAP

Quankun Wang, Jinguo You, Benyuan Zou, Yu Chen, Xingrui Huang, Lianyin Jia
2021 IEEE Access  
According to the definition of cover capacity, the greater the Ca of the equivalence class, the more data cells covered by the equivalence class, the stronger the ability to answer queries.  ...  introduce the equivalence class cover capacity Ca , which refers to the number of data cells covered or contained by the equivalence class.  ... 
doi:10.1109/access.2021.3120278 fatcat:3magpumerjarjooqstbogjdxua

SchemaSQL: An extension to SQL for multidatabase interoperability

Laks V. S. Lakshmanan, Fereidoon Sadri, Subbu N. Subramanian
2001 ACM Transactions on Database Systems  
also permits the creation of views whose schema is dynamically dependent on the contents of the input instance. (4) While aggregation in SQL is restricted to values occurring in one column at a time,  ...  querying of both data and schema. (2) It can be used to transform data in a database in a structure substantially different from original database, in which data and schema may be interchanged. (3) It  ...  A detailed and general study of information capacity equivalence and preservation for restructured views is beyond the scope of this article.  ... 
doi:10.1145/503099.503102 fatcat:ofhbm5ug2jge3m7gponkrtuf6q

Querying XML data sources that export very large sets of views

Bogdan Cautis, Alin Deutsch, Nicola Onose, Vasilis Vassalos
2011 ACM Transactions on Database Systems  
We say that query Q is expressible by the specification P if it is equivalent to some expansion of P. Q is supported by P if it has an equivalent rewriting using some finite set of P's expansions.  ...  We study the problem of querying XML data sources that accept only a limited set of queries, such as sources accessible by Web services which can implement very large (potentially infinite) families of  ...  For a set of views V, defined by XP queries over a document D, by D V we denote the set of view documents {doc(v)|v ∈ V}.  ... 
doi:10.1145/1929934.1929939 fatcat:jb2nmk5yqzbgrmryvcyugyvwji

Cut-Equivalent Trees are Optimal for Min-Cut Queries [article]

Amir Abboud, Robert Krauthgamer, Ohad Trabelsi
2020 arXiv   pre-print
Min-Cut queries are fundamental: Preprocess an undirected edge-weighted graph, to quickly report a minimum-weight cut that separates a query pair of nodes s,t.  ...  Algorithms 1998) implies the first near-linear time construction of cut-equivalent trees.  ...  Denote by T a cut-equivalent tree of G, and by α T the (multi-)set of edges in T that are the answers to (exact) Min-Cut queries in T of the pairs in Q i .  ... 
arXiv:2009.06090v1 fatcat:l4sxbyvoqvdb7aqn4vwjunuidy

XML Reconstruction View Selection in XML Databases: Complexity Analysis and Approximation Scheme [chapter]

Artem Chebotko, Bin Fu
2010 Lecture Notes in Computer Science  
accessed by XML queries.  ...  Query evaluation in an XML database requires reconstructing XML subtrees rooted at nodes found by an XML query.  ...  We can only select a subset of leaves. This is equivalent to the Knapsack problem. 2 Finally, we state the NP-hardness of the XML reconstruction view selection problem.  ... 
doi:10.1007/978-3-642-17461-2_8 fatcat:kangfpvchzaqhcmbzebyz4u7pu

Optimizing View Queries in ROLEX to Support Navigable Result Trees [chapter]

P. Bohannon, S. Ganguly, H.F. Korth, P.P.S. Narayan, P. Shenoy
2002 VLDB '02: Proceedings of the 28th International Conference on Very Large Databases  
The ROLEX query optimizer uses a characterization of the navigation behavior of an application, and optimizes view queries to minimize the expected cost of that navigation.  ...  This paper presents the architecture of ROLEX, including its model of query execution and the query optimizer.  ...  Acknowledgements The authors would like to thank Prasan Roy for support of the VOLCANO-style optimizer on which ROLEX is based.  ... 
doi:10.1016/b978-155860869-6/50019-6 dblp:conf/vldb/BohannonGKNS02 fatcat:47amxf5cgffgxpz4a26rlq6c7q


1996 International Journal of Cooperative Information Systems  
Query reformulation is made difficult by the variety of semantic knowledge that is used to describe the MDBMS.  ...  It is general enough to re-use the results of previously computed queries in the MDBMS.  ...  They cite an extension of their algorithm [Levy95b] , which is able to answer a larger class of queries, by matching a conjunctive query against a conjunctive view, to produce an equivalent query, and  ... 
doi:10.1142/s0218843096000166 fatcat:gyh7todizrcghcyehlxaahvh5y

Algorithm for Term Linearizations of Aggregate Queries with Comparisons [chapter]

Victor Felea, Violeta Felea
2012 Lecture Notes in Computer Science  
To study the equivalence of a query with its rewriting query, the so called "linearizations of a query" need to be computed.  ...  We consider the problem of rewriting queries based exclusively on views. Both queries and views can contain aggregate functions and include arithmetic comparisons.  ...  In case of finding a query Q , corresponding to a given query Q, and expressed by the views from V, such that Q is equivalent to Q , the problem of (RQV ) for the query Q has a solution.  ... 
doi:10.1007/978-3-642-32597-7_35 fatcat:chlkjxnqvjdztc7fjm3734adem


2019 Zenodo  
A data warehouse uses multiple materialized views (MV) to efficiently process a given set of queries.  ...  This paper gives the results of proposed minimize attribute involvement based MV selection algorithm for query processing. First, select MV by clustering the workload of the query.  ...  Planning, operational coordination and supervision are carried out by LLDIKTI Region VI of Central Java. The authors express their gratitude for their attention and guidance.  ... 
doi:10.5281/zenodo.3256437 fatcat:sj67vnzskrb3lmnx426qvwvb2i
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