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The method of the canonical connection introduced by Maier and Ullman provides an optimal procedure for query processing in universal-relation databases. ... We present an algorithm for computing canonical connections in a database scheme which is more efficient than the classical algorithm based on tableau reduction. ... Among these characterizations and properties, the following two will be used in our approach to the query optimization problem in universal-relation databases: (a)  if H is acyclic then CC(H, X ) ...doi:10.1006/jcss.1998.1570 fatcat:5pguq4bfyvag3lowc6pqrp7guy
Main memory database is a database management system in which the total or most of data are stored in the main memory. ... In this paper, main memory database and index are introduced, T-tree index algorithm which is the most representative is research and analysis, and the T-tree optimization ideas are put forward. ... In recent years, some colleges and universities are in the related research and experiment. ...doi:10.12783/dtcse/itms2016/9459 fatcat:ikjixvbpnndwbobm4mme5cfvs4
In this paper, an approach is presented which is able to generate an optimal query processing plans for a given user query. ... The efficiency of processing queries in an embedded database is critical for the system performance. ... In the first phase, the algorithm builds access plan for every relation in the query. Typically, there are several different access plans for a relation. ...doi:10.7763/ijcte.2017.v9.1161 fatcat:ibbjmnnpv5dfzfbijjmij5wjsa
Topics in Information Systems
They standardize and simplify a query, and assign it (where possible) to a class of queries for which fast algorithms exist. ... In addition, researchers identified classes of queries for which fast special-purpose algorithms exist. ...doi:10.1007/978-3-642-82375-6_1 fatcat:frcrnj5rlnhfnbatu53pe4t7xu
A second result of our study is that universal quantification should be expressed directly in a database query language because most query optimizers do not recognize the rather indirect formulations available ... Universal quantification is not supported directly in most database systems despite the fact that it adds significant power to a system's query processing and inference capabilities, in particular for ... This is another strong argument for directly supporting universal quan- However, it is much easier for a query optimizer to detect a "for-all" or "contains" expression and to rewrite it into a query evaluation ...doi:10.1145/210197.210202 fatcat:joso33b7ajdcra4b7br23ho7jy
University Computing : The Bulletin of the IUCC
Breuer, University of Cambridge Abstract We give a formal calculus, based on higher-order functions and indexed data, for the evaluation of database queries. ... The transform calculus itself is a set of algorithms, which make new algorithms, out of old algorithms, yielding as a result an algorithm which may eventually be applied to data as a database query. ...
In database theory, a database is modeled as a finite structure over a finite relational vocabulary o. ... The elements appearing in the relations of the database come from a fixed infinite universe of dis- course, modeled as some typically infinite structure @ over some For the web version of Mathematical ...
The VLDB journal
For self-join-free conjunctive queries, there is only a single plan, in which case the authors show that the query evaluation is in PTIME. The paper "Fast and Scalable Inequality Joins" ... The authors propose a method for probabilistic inference, where a query is evaluated entirely in the database engine by evaluating a fixed number of query plans, each providing an upper bound on the true ... investigates the problem of how to maintain and query hierarchical data in a relational database system in the presence of complex, possibly skewed structural updates at high data rates. ...doi:10.1007/s00778-016-0450-5 fatcat:bs244b7w6fbflnahsx5cctaqfi
Surprisingly, our empirical investigation using a commercial DBMS finds it is not necessary to adjust query optimization when shifting relations from disk to flash-an SSD-oblivious optimizer generally ... Conventional query optimizers assume a storage cost model where sequential IOs are far less costly than random IOs, and select access paths and join algorithms based on this assumption. ... Because of the complexity of the interplay between available memory capacity and relation sizes for join optimization  , we do not have a specific expectation that one join algorithm will universally ...dblp:conf/vldb/PelleyLW11 fatcat:q5vifl57vjgh3lkleahojoh3y4
2010 IEEE 26th International Conference on Data Engineering Workshops (ICDEW 2010)
We search for relational algorithms that require no changes to the database engine. ... sets that are stored in a relational database management system. ... when applied to social networks and searching for people, contacts or shared interests is very different from the search over documents studied in information retrieval. ...doi:10.1109/icdew.2010.5452773 fatcat:oyq2tujbvjfpxjlyixux5q57vu
Lecture Notes in Computer Science
CGO is a sound optimizer based on genetic programming that uses a subset of the cost-model of IBM R DB2 R Universal Database TM (DB2 UDB) for selection in order to produce new generations of query plans ... Our study shows that CGO is very competitive either as a standalone optimizer or as a fast post-optimizer. ... IBM, DB2, and DB2 Universal Database are trademarks or registered trademarks of International Business Machines Corporation in the United States, other countries, or both. ...doi:10.1007/11758501_25 fatcat:4znesaiqvfg7lkxqvyrh7pxezi
Introduction to SQL A special purpose programming language SQL was designed for managing data held in a RDBMS (relational database management system).SQL consists of a DDL (Data Definition Language), DML ... This information is essential for the companies to predict the behaviors of their customers, and to optimize the use of resources. ... UsingSQL,where RDBMS' are very fast and writing queries in SQL for graph traversal operations or algorithms will not be easy. ...doi:10.17485/ijst/2016/v9i35/98941 fatcat:dj23kqqulvhftee4bp55ezau7q
In all three occasions, the Canadian Databases community served as backbone for the organizing and the programme committees. ... The conference was a huge success for its time, attracting almost 100 papers and more than 150 participants. We have come a long way since then! ... compiled similar guides for ICSE 2001 and RE 2001, respectively ...doi:10.1109/dsn.2006.75 dblp:conf/dsn/X06 fatcat:k4duddvbk5glboxkqxkkfsh4p4
With the advance of optimization and merger colleges and universities, a university often contains more than one campus. ... The model detects the intrusion by dividing the clusters in the clustering result into normal clusters and abnormal clusters and analyzing the weighted average density of object x to be detected in each ... For further observations, we found that when a = 0:9, the evolution is very fast, but it quickly enters premature development, becoming a local optimum. ...doi:10.1155/2020/8819083 fatcat:7cezhk7wmvdktdcukapoix2lau
The new drug should have similar behavior in terms of the chemical molecular formula to a known drug by applying similarity searching algorithms. ... We achieved significant results in terms of performance and execution time in both CUDA and OPENMP designs of fast population count method with data conversion when compared to the sequential code. ... This is the place to thanks from the anonymous reviewers for their professional comments about our work. ...doi:10.9790/0661-1464352 fatcat:swiextx76nhupdkakgvr6moc5u
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