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DB Integrator: Open Middleware for Data Access

Richard Pledereder, Vishu Krishnamurthy, Michael Gagnon, Mayank Vadodaria
1995 Digital technical journal of Digital Equipment Corporation  
Digital's DB Integrator provides robust data access by supporting heterogeneous query optimization, location transparency, global consistency, resolution of semantic differences, and security checks.  ...  The DB Integrator enables security checks without interfering with the access controls specified in the underlying data sources.  ...  Join Processing. Highly efficient processing of joins and unions is important in any commercial database; it is crucial for a multidatabase system.  ... 
dblp:journals/dtj/PlederederKGV95 fatcat:tlm6xk2gzjdrrgyqgih56bqebe

Query processing in multistore systems: an overview

Carlyna Bondiombouy, Patrick Valduriez
2016 International Journal of Cloud Computing  
In this paper, we give an overview of query processing in multistore systems. We start by introducing the recent cloud data management solutions and query processing in multidatabase systems.  ...  In Section 3, we review the main query processing techniques for multidatabase systems, based on the mediator-wrapper architecture.  ...  A bind join is a nested loop join in which intermediate results (e.g. values for the join predicate) are passed from the outer relation to the wrapper for the inner relation, which uses these results to  ... 
doi:10.1504/ijcc.2016.10001884 fatcat:jpuixv6mxzhmdkuqrmqbgbbl24

Query processing in multistore systems: an overview

Carlyna Bondiombouy, Patrick Valduriez
2016 International Journal of Cloud Computing  
In this paper, we give an overview of query processing in multistore systems. We start by introducing the recent cloud data management solutions and query processing in multidatabase systems.  ...  In Section 3, we review the main query processing techniques for multidatabase systems, based on the mediator-wrapper architecture.  ...  A bind join is a nested loop join in which intermediate results (e.g. values for the join predicate) are passed from the outer relation to the wrapper for the inner relation, which uses these results to  ... 
doi:10.1504/ijcc.2016.080903 fatcat:etteedwysbcyfidbaeh7x2lrne

Performance analysis of three text-join algorithms

W. Meng, C. Yu, W. Wang, N. Rishe
1998 IEEE Transactions on Knowledge and Data Engineering  
When a multidatabase system contains textual database systems (i.e., information retrieval systems), queries against the global schema of the multidatabase system may contain a new type of joins-joins  ...  Three algorithms for processing such a type of joins are presented and their I/O costs are analyzed in this paper.  ...  This research is supported in part by the following grants: U.S. National Science Foundation grants under IRI-9309225 and IRI-9509253, U.S.  ... 
doi:10.1109/69.687979 fatcat:zw7c2rmifrcvhjidzjrsp2l37m

SchemaSQL: An extension to SQL for multidatabase interoperability

Laks V. S. Lakshmanan, Fereidoon Sadri, Subbu N. Subramanian
2001 ACM Transactions on Database Systems  
relational multidatabase systems.  ...  We also discuss the applicability of SchemaSQL for handling semantic heterogeneity arising in a multidatabase system.  ...  ,R 1 .obj n as attr n from R 1 outer join R 2 outer join .. . outer join R m where R 1 .obj[1..i − 1] = R 2 .obj[1..i − 1] and . . . and R 1 .obj[1..i − 1] = R m .obj[1..i − 1] and R 1 .obj[i + 1..n] =  ... 
doi:10.1145/503099.503102 fatcat:ofhbm5ug2jge3m7gponkrtuf6q

Extending data warehouses by semiconsistent views

Lutz Schlesinger, Wolfgang Lehner
2002 Design and Management of Data Warehouses  
We describe the architecture of our information middleware approach, develop different join semantics to combine different data sources, and propose algorithms for picking time consistent cuts in the history  ...  To avoid out-dated information the alternative is to query the data sources directly, which results in higher query runtimes or in the complete failure producing a result if data sources are currently  ...  •mediator and database middleware systems / multidatabase systems Database middleware systems like DataJoiner/Garlic ([IBM01a], [IBM01b]) or mediator systems in general ([Wied92], e.g.  ... 
dblp:conf/dmdw/SchlesingerL02 fatcat:6627gku4dbh2hn7jk3p6p7n5lm

Adding Conflict Resolution Features to a Query Language for Database Federations

Kai-Uwe Sattler, Stefan Conrad, Gunter Saake
2000 Australasian Journal of Information Systems  
In this paper we present a SQL extension for defining and querying database federations.  ...  This language addresses in particular the resolution of integration conflicts by providing mechanisms for mapping attributes, restructuring relations as well as extended integration operations.  ...  and outer join.  ... 
doi:10.3127/ajis.v8i1.262 fatcat:cj2u4uedlnfijauv6lamci2xjq

CloudMdsQL: querying heterogeneous cloud data stores with a common language

Boyan Kolev, Patrick Valduriez, Carlyna Bondiombouy, Ricardo Jiménez-Peris, Raquel Pau, José Pereira
2015 Distributed and parallel databases  
, e.g. by pushing down select predicates, using bind join, performing join ordering, or planning intermediate data shipping.  ...  In this paper, we present the design of a cloud multidatastore query language (CloudMdsQL), and its query engine.  ...  To be easily optimizable so that efficient query optimization, introduced in stateof-the-art multidatabase systems, can be reused (e.g. exploiting bind joins [11] or shipping the smallest intermediate  ... 
doi:10.1007/s10619-015-7185-y fatcat:mx5jhzyejvgctilcoeuc6ojojm

Online Processing Redux

Joseph M. Hellerstein
1997 IEEE Data Engineering Bulletin  
Membership in the TC on Data Engineering is open to all current members of the IEEE Computer Society who are interested in database systems.  ...  Its scope includes the design, implementation, modelling, theory and application of database systems and their technology.  ...  In [11] , a technique is suggested to reduce query response time in multidatabase systems.  ... 
dblp:journals/debu/Hellerstein97 fatcat:oh6ekw3jgngtzlgzsbfgieavq4

Benchmarking polystores: The CloudMdsQL experience

Boyan Kolev, Raquel Pau, Oleksandra Levchenko, Patrick Valduriez, Ricardo Jimenez-Peris, Jose Pereira
2016 2016 IEEE International Conference on Big Data (Big Data)  
A major capability is to exploit the full power of each of the underlying data stores by allowing native queries to be expressed as functions and involved in SQL statements.  ...  In this paper, we introduce the benchmarking of the CloudMdsQL polystore and evaluate the performance benefits of important features enabled by the query language and engine.  ...  The problem of accessing heterogeneous data sources has long been studied in the context of multidatabase and data integration systems [7] .  ... 
doi:10.1109/bigdata.2016.7840899 dblp:conf/bigdataconf/KolevPLVJP16 fatcat:ro46xbo6j5cl7l7gwakwn24uqe

A METHODOLOGY FOR QUERY REFORMULATION IN CIS USING SEMANTIC KNOWLEDGE

DANIELA FLORESCU, LOUIQA RASCHID, PATRICK VALDURIEZ
1996 International Journal of Cooperative Information Systems  
We consider a multidatabase system (MDBMS) with a common object-oriented model, based on the ODMG standard, and local databases that may be relational, object-oriented, or file systems.  ...  It is general enough to re-use the results of previously computed queries in the MDBMS.  ...  , or file systems.  ... 
doi:10.1142/s0218843096000166 fatcat:gyh7todizrcghcyehlxaahvh5y

Data fusion

Jens Bleiholder, Felix Naumann
2008 ACM Computing Surveys  
The development of the Internet in recent years has made it possible and useful to access many different information systems anywhere in the world to obtain information.  ...  Finally, the article features a comprehensive survey of data integration systems from academia and industry, showing if and how data fusion is performed in each.  ...  As the outer join operator in general is not associative, combining more than two tables by an outer join may result in different result tables, depending on the order in which the tables are joined.  ... 
doi:10.1145/1456650.1456651 fatcat:hpcouuy7ifgbhkkh3clcxvi7wq

Interactive example-driven integration and reconciliation for accessing database federations

Kai-Uwe Sattler, Stefan Conrad, Gunter Saake
2003 Information Systems  
This integration approach is supported by a multidatabase query language, which provides special mechanisms for conflict resolution.  ...  In addition, we discuss basic techniques for supporting the detection of instance-level conflicts. r  ...  For a join operation the map is constructed by applying an outer join, too. In addition to the coloring for the union operation, a further kind of conflict is considered.  ... 
doi:10.1016/s0306-4379(02)00023-6 fatcat:n7ejsagxnffv3pp6pkdflmhhva

A Polygen Model for Heterogeneous Database Systems: The Source Tagging Perspective

Y. Richard Wang, Stuart E. Madnick
1990 Very Large Data Bases Conference  
This paper studies heterogeneous database systems from the multiple (poly) source @rrt) perspective.  ...  The significance of this paper lies not only in a precise characterization of a practical problem and a solution per se, but also in the establishment of a foundation for resolving many other critical  ...  An Outer Naturul Join is an outer join with the join attributes coalesced 1221. We define an Outer Natural Primary loin as an Outer Natural loin on the primary key of a polygen relation.  ... 
dblp:conf/vldb/WangM90 fatcat:g35tt4hpjrf5rek3vvitcmjgja

Parallel Polyglot Query Processing on Heterogeneous Cloud Data Stores with LeanXcale

Boyan Kolev, Oleksandra Levchenko, Esther Pacitti, Patrick Valduriez, Ricardo Vilaca, Rui Goncalves, Ricardo Jimenez-Peris, Pavlos Kranas
2018 2018 IEEE International Conference on Big Data (Big Data)  
Moreover, efficient optimization techniques, such as bind join, can still take place to improve the performance of selective joins.  ...  The blooming of different cloud data stores has turned polystore systems to a major topic in the nowadays cloud landscape.  ...  The system enables cross-island queries (across different data models) by moving intermediate datasets between islands in an optimized way.  ... 
doi:10.1109/bigdata.2018.8622187 dblp:conf/bigdataconf/KolevLPVVGJK18 fatcat:ticpdcbionc7dgzxqfv3zwhfpi
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