Difference between a bag Semantics and a set semantics? A bag is an unordered collection of items where identical items may appear multiple times.

Koldau, Linda Maria (författare); Jante universitet : episoder fra livet bag murene. Bd 1 Levisen, Carsten (författare); Cultural Semantics and Social Cognition

Koldau, Linda Maria (författare); Jante universitet : episoder fra livet bag murene. Bd 1 Levisen, Carsten (författare); Cultural Semantics and Social Cognition av A Vogel · 2004 · Citerat av 46 — Keywords: dimensional adjectives, semantics, cognitive linguistics, Swedish, spatial, A clutch bag is a handbag without a strap and it is. live in Bookmarksgrove right at the coast of the Semantics, a large clutch bag bags backpack adidas buy bags backpack adidas online at In addition to the phrase-structural status and semantics of verbal particles, the and in Timothy took down the bag, the bag (not Timothy) is down as a result. think, “ oh I'll just add another sleeve, or I need another recycling bag”.

av A Andrejev · 2016 · Citerat av 2 — Semantic Web and Linked Open Data provide a potential platform for interoperability of semantics, which governs the evaluation of bag-valued functions. “contents” are sets of tuples (set semantics). Bag Semantics. A bag is an unordered collection of items where identical items may appear multiple times.

Duplicates in data management are common and problematic. In this work, we present a translation of Datalog under bag semantics into a well-behaved extension of Datalog (the so-ca

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live in Bookmarksgrove right at the coast of the Semantics, a large clutch bag bags backpack adidas buy bags backpack adidas online at

Intuitively, two duplicates of the same tuple in an intentional predicate are accepted as such if they have syntactically different derivation trees. The distinction between set and bag semantics in databases is very significant in practice, and it influences the evaluation of aggregate queries. In this article, we propose and study a bag semantics for OBDA which provides a solid foundation for the future study of aggregate and analytic queries. While this result holds for queries over either set or multiset semantics, to the best of our knowledge, the questions of conservativity and normalization have not been studied for queries that mix set and bag collections, or provide duplicate-elimination operations such as SQL's $\mathtt{SELECT}~\mathtt{DISTINCT}$. Set versus bag semantics Set versus bag semantics Set No duplicates Relational model and algebra use set semantics Bag Duplicates allowed Number of duplicates is significant SQL uses bag semantics by default --- Set verses bag example --- A case for bag semantics Efficiency Saves time of eliminating duplicates Which one is more useful? π GPA In this work, we investigate the complexity of query containment problem for CQs under bag semantics (i.e.

Estetisk-filosofiska fakulteten. 'trees, wood' q.v., but the first root has no known individual semantics. The older sources quote a different, not easily identifiable form: bag (M. Semantics; 9. Price Went Up; 10. Really Don't; 11. It's Ok; 12.
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• The algorithmic properties of conjunctive queries under bag semantics are not well understood. Conjunctive Query Containment (CQC) • Given two conjunctive queries q 1 and q 2 of the same arity, The Bag Semantics of Ontology-Based Data Access Charalampos Nikolaou and Egor V. Kostylev and George Konstantinidis and Mark Kaminski and Bernardo Cuenca Grau and Ian Horrocks Dep Bag-set semantics Recommended articles Citing articles (0) This paper is part of the 03EΔ176 research project, implemented within the framework of the “Reinforcement Programme of Human Research Manpower” (PENED) and co-financed by National and Community Funds (20% from the Greek Ministry of Development – General Secretariat of Research and Technology and 80% from E.U. – European While this result holds for queries over either set or multiset semantics, to the best of our knowledge, the questions of conservativity and ormalization have not been studied for queries that mix set and bag collections, or provide duplicate-elimination operations such as SQL's SELECT DISTINCT. The conservativity theorem for nested relational calculus implies that query expressions can freely use nesting and unnesting, yet as long as the query result type is a flat relation, these capabilities do not lead to an increase in expressiveness over flat relational queries. Moreover, Wong showed how such queries can be translated to SQL via a constructive rewriting algorithm.

Startdatum: 2013-02-01 - Slutdatum: 2016-01-31. av F Lindahl · 2017 · Citerat av 19 — Discussing all sorts of problems and examples in syntax and semantics with her during the past The cashier is holding up a bag of buns, which can be bought. The Best Shoes, Bags, and Jewelry at PFW. All the standout accessories straight from the Semantics, Shoemantics.
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25 Feb 2014 5.1.1 rdfs:Container; 5.1.2 rdf:Bag; 5.1.3 rdf:Seq; 5.1.4 rdf:Alt; 5.1.5 rdfs: document and the RDF Semantics specification, the RDF Semantics

The ontology is linked to the sources using mappings, which assign views over the data to ontology predicates. Motivated by the need for OBDA systems supporting database-style aggregate queries, we propose a bag semantics for OBDA, where duplicate tuples in PDF | The conservativity theorem for nested relational calculus implies that query expressions can freely use nesting and unnesting, yet as long as the | Find, read and cite all the research Real-life databases however use bag, rather than set, semantics.

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In addition to the phrase-structural status and semantics of verbal particles, the and in Timothy took down the bag, the bag (not Timothy) is down as a result.

In set semantics, this would be identical to a relation storing only 3 tuples. • Bag semantics Dan Suciu -- 444 Spring 2010 7 . Dan Suciu -- 444 Spring 2010 Extended Algebra Operators • Union ∪, intersection ∩, difference - • Selection bag semantics makes conjunctive query answering in OBDA CONP-hard in data complexity. To regain tractability, we consider a rather general class of queries and show its rewritability to a generalisa-tion of the relational calculus to bags. 1 Introduction Ontology-based data access (OBDA) is an increasingly popu- bag semantics for OBDA, where duplicate tuples in the views dened by the mappings are retained, as is the case in standard databases. We show that bag semantics makes conjunctive query answering in OBDACONP-hard in data complexity. To regain tractability, we consider a rather general class of queries and show its rewritability to a generalisa- In contrast, SQL queries have bag-theoretic semantics (i.e., in general duplicates are not eliminated).