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Efficient Enumeration for Conjunctive Queries over X-underbar Structures [chapter]

Guillaume Bagan, Arnaud Durand, Emmanuel Filiot, Olivier Gauwin
2010 Lecture Notes in Computer Science  
We investigate efficient enumeration algorithms for conjunctive queries for databases over binary relations that satisfy the X property.  ...  We first show that the result of an n-ary conjunctive query Q over an X structure S can be enumerated with a delay in O(n·|S|·|Q|) between two consecutive n-tuples.  ...  We thank Joachim Niehren for fruitful discussions. This work was partially supported by the project ANR ENUM (ANR-07-BLAN-0327).  ... 
doi:10.1007/978-3-642-15205-4_10 fatcat:jpeof6wlezfhjebsbfqoswdbaq

Processing queries on tree-structured data efficiently

Christoph Koch
2006 Proceedings of the twenty-fifth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems - PODS '06  
This is a survey of algorithms, complexity results, and general solution techniques for efficiently processing queries on tree-structured data.  ...  The techniques belong to five groups: 1. employing orders on the nodes of the tree for efficient labeling schemes and structural joins, 2. linear-time algorithms for evaluating Horn-SAT (the datalog technique  ...  Lemma 6.4 Let A be a structure with the X-property w.r.t. < and let Θ be an arc-consistent pre-valuation on A for a given conjunctive query over the relations of A.  ... 
doi:10.1145/1142351.1142382 dblp:conf/pods/Koch06 fatcat:2zanpmquibamjkr2m45dfpgngq

Efficient evaluation of n-ary conjunctive queries over trees and graphs

François Bry, Tim Furche, Benedikt Linse, Andreas Schroeder
2006 Proceedings of the eighth ACM international workshop on Web information and data management - WIDM '06  
Despite a considerable body of research on the optimization of such queries over tree-shaped XML data, little attention has been paid so far to efficient access to graph-shaped XML, RDF, or Topic Maps.  ...  We propose the first evaluation technique for n-ary conjunctive queries that applies to both tree-and graph-shaped data and retains the same complexity as the best known approaches that are restricted  ...  Conjunctive queries over tree data form a common formal basis for the query core of a large set of XML query languages such as XPath [6] , and thus XQuery; conjunctive queries over graph data for RDF  ... 
doi:10.1145/1183550.1183555 dblp:conf/widm/BryFLS06 fatcat:3svxmjuvwfe7thly2pv3f43gza

A Circuit-Based Approach to Efficient Enumeration [article]

Antoine Amarilli, Pierre Bourhis, Louis Jachiet, Stefan Mengel
2017 arXiv   pre-print
Our results yield a framework for efficient enumeration that applies to all problems whose solutions can be compiled to structured d-DNNFs.  ...  This gives an independent proof of constant-delay enumeration for MSO formulae with first-order free variables on bounded-treewidth structures.  ...  Efficient enu- meration for conjunctive queries over X-underbar structures. In CSL, 2010. 7 Guillaume Bagan, Arnaud Durand, and Etienne Grandjean.  ... 
arXiv:1702.05589v2 fatcat:druqegrjnrh65lntqvkfwf3kca

Yedalog: Exploring Knowledge at Scale

Brian Chin, Daniel Von Dincklage, Vuc Ercegovac, Peter Hawkins, Mark S. Miller, Franz Och, Christopher Olston, Fernando Pereira, Marc Herbstritt
2015 Summit on Advances in Programming Languages  
Yedalog extends Datalog, incorporating not only computational features from logic programming, but also features for working with data structured as nested records.  ...  By contrast, most existing tools for data-parallel computation embed a sublanguage of data-parallel pipelines in a general-purpose language, or vice versa.  ...  ., Store(x, y) as a shorthand for Store{0: x, 1: y}). Core operators include unification (==), conjunction (,), disjunction (|), negation (!)  ... 
doi:10.4230/lipics.snapl.2015.63 dblp:conf/snapl/ChinDEHMOOP15 fatcat:pkmhfbb5yvbnfhk2btfxijhdfu

Equality, types, modules, and (why not?) generics for logic programming

Joseph A. Goguen, José Meseguer
1984 The Journal of Logic Programming  
to equations over user defined abstract data types (ADTs).  ...  The original vision of logic programming called for using predicate logic as a programming language [35,48].  ...  Section 7.3 considers solving equations over user defined sorts and Section 4 describes a sublogic within which equations over user defined sorts can be made solvable with reasonable efficiency.  ... 
doi:10.1016/0743-1066(84)90004-9 fatcat:cg3yohzau5hgfd3o2gtmhnqe4m

A quantum production model

Luís Tarrataca, Andreas Wichert
2011 Quantum Information Processing  
We then expand on this result in order to accommodate for the requirements of quantum computation.  ...  Our approach focuses on initially developing a model for a reversible production system which is a simple mapping of Bennett's reversible Turing machine.  ...  Subsequently, a more efficient model for a universal quantum Turing machine was proposed in [6] .  ... 
doi:10.1007/s11128-011-0241-2 fatcat:lvrvgxfgunduxlpa47p75wqaxu

On the Semantics of Intensionality and Intensional Recursion [article]

G. A. Kavvos
2017 arXiv   pre-print
This is a familiar setting for computer scientists, who often study different programs or processes that are interchangeable, i.e. extensionally equal, even though they are not implemented in the same  ...  We often call the arrow e : X → A a (Q, X)-enumeration, and say that A is (Q, X)-enumerable. We are very fond of (Q, X)-enumerations for two reasons.  ...  Let us now investigate the structure of 2 X, for any assembly X. For each (x, a) ∈ | X|, we have that (x, a) X = {a}.  ... 
arXiv:1712.09302v1 fatcat:5jfwgc2yujglraaxsuqr7jvmqi

The evolution of Smalltalk: from Smalltalk-72 through Squeak

Daniel Ingalls
2020 Proceedings of the ACM on Programming Languages (PACMPL)  
Ted Kaehler came back from graduate school over Christmas 1972 then wrote line-drawing routines for the bitmap display.  ...  and instances, • a structure for code (we used vectors and sub-vectors), and • the evaluator that Alan had designed. 2 This test sent the message factorial to the object 6, which would in turn send factorial  ...  Drop the Special Characters and Go for ASCII The move to ASCII went fairly smoothly, except for the loss of left arrow for assignment (for a while we were stuck with underbar), and the loss of an infix  ... 
doi:10.1145/3386335 fatcat:p33btb4rmrdatoidubvy5bfoe4

Bi-Arc Digraphs and Conservative Polymorphisms [article]

Pavol Hell and Akbar Rafiey and Arash Rafiey
2020 arXiv   pre-print
The complexity of the recognition problem for digraphs with conservative semilattice polymorphisms was an open problem, while it was known to be NP-complete for certain more complex relational structures  ...  We complement our result by providing a complete dichotomy classification of which general relational structures have polynomial or NP-complete recognition problems for the existence of conservative semilattice  ...  Efficient enumeration for conjunctive queries over x-underbar structures. In International Workshop on Computer Science Logic, pages 80–94. Springer, 2010.  ... 
arXiv:1608.03368v5 fatcat:es537slt4fgz5d6ke25aqcdjby

LIPIcs, Volume 32, SNAPL'15, Complete Volume [article]

Thomas Ball, Rastislav Bodik, Shriram Krishnamurthi, Benjamin S. Lerner, Greg Morrisett
We thank Josef Widder for the fruitful discussions on this subject, Heather Miller and Philipp Haller for their help with the pickling library, and the anonymous reviewers for their comments.  ...  The Need for Language Support for Fault-Tolerant Distributed Systems Robin Milner, Joachim Parrow, and David Walker Toward a Dependability Case Language and Workflow for a Radiation Therapy System Acknowledgments  ...  ., Store(x, y) as a shorthand for Store{0: x, 1: y}). Core operators include unification (==), conjunction (,), disjunction (|), negation (!)  ... 
doi:10.4230/lipics.snapl.2015 fatcat:ljoxwa7wp5achn2tbrmpriez7y