Martin Grohe, Thomas Schwentick, Luc Segoufin  Home/Search
Context Related
| uic.edu/~grohe/pub/grid.ps Cached: PS.gz PS PDF This document uses CoBlitz to cache paper downloads. If your firewall is blocking outgoing connections to port 3125, you can use these links to download local copies.
Image Update HelpPS.gz PS PDF From: uic.edu/~grohe/pub (more) (Enter author homepages) |
Rate this article:      (best)Comment on this article |
Abstract: The evaluation of conjunctive queries is hard both with respect to its combined complexity (NPcomplete) and its parameterized complexity (W[1]-complete). It becomes tractable (PTIME for combined complexity, FPT for parameterized complexity), when conjunctive queries have a bounded treewidth structure. In this paper we show that, in a sense, this is optimal both with respect to combined and parameterized complexity : Evaluating conjunctive queries is tractable precisely for those classes of... (Update)
Context of citations to this paper: More
.... the characterization of classes of formulas for which the evaluation of first order conjunctive queries is fixed parameter tractable, GSS01] This happens iff the treewidth of the (underlying graph of the) formulas is of bounded. 6 2 Discussion and proofs Various weaker...
...same color, then h(x) and h(y) have the same color. Parameter: jHj W[1] complete (membership is easy; hardness by reduction from Clique [77]) Note: Related to Database Conjunctive Query Evaluation. Solvable in polynomial time when c = 1. Colored Proper Interval Graph Completion...
Cited by: More
On Preservation under Homomorphisms and Unions of.. - Atserias, Dawar.. (2004) (Correct)
Parameterized Complexity for the Skeptic - Downey (2003) (Correct)
Design of a Role-based Trust-management Framework - Li, Mitchell, Winsborough (Correct)
Similar documents (at the sentence level):
63.4%: When is the Evaluation of Conjunctive Queries Tractable? - Grohe, Schwentick, Segoufin (2000) (Correct)
Active bibliography (related documents): More All
0.3: Descriptive and Parameterized Complexity - Grohe (1999) (Correct)
0.2: A Tractability Result for Reasoning with Incomplete.. - Department Of Computer (Correct)
0.2: Query evaluation via tree-decompositions (Extended Abstract) - Flum, Frick, Grohe (Correct)
Similar documents based on text: More All
0.4: Compilation and Approximation of Conjunctive Queries by.. - Goasdoué, Rousset (2002) (Correct)
0.3: Path Queries on Compressed XML - Buneman, Grohe, Koch (2003) (Correct)
0.2: Database Interrogation Using Conjunctive Queries - Micha Bielecki Warsaw (Correct)
Related documents from co-citation: More All
9: Fixed-parameter tractability and Completeness I: Basic Results - Downey, Fellows - 1995
3: The parameterized complexity of some problems in logic and linguistics - Downey, Fellows et al. - 1994
3: Parameterized circuit complexity and the W hierarchy - Downey, Fellows et al. - 1997
BibTeX entry: (Update)
M. Grohe, T. Schwentick, and L. Segoufin. When is the evaluation of conjunctive queries tractable? In STOCS'01, pages xx--yy, 2001. http://citeseer.ist.psu.edu/article/grohe00when.html More
@inproceedings{ grohe01when,
author = "Martin Grohe and Thomas Schwentick and Luc Segoufin",
title = "When is the evaluation of conjunctive queries tractable?",
booktitle = "{ACM} Symposium on Theory of Computing",
pages = "657-666",
year = "2001",
url = "citeseer.ist.psu.edu/article/grohe00when.html" }
Citations (may not include all citations):379 The complexity of relational query languages (context) - Vardi - 1982
232 Optimal implementation of conjunctive queries in relational .. (context) - Chandra, Merlin - 1977
222 Fixed-parameter tractability and completeness II: On complet.. - Downey, Fellows - 1995
189 Parameterized Complexity - Downey, Fellows - 1999
49 Excluding a planar graph (context) - Robertson, Seymour - 1986
48 Conjunctive query containment revisited - Chekuri, Rajaraman - 1997
40 Algorithms for acyclic database schemes (context) - Yannakakis - 1981
22 Hypertree decompositions and tractable queries (context) - Gottlob, Leone et al. - 1999
21 Query-evaluation via tree-decompositions - Flum, Frick et al. - 2001
20 Perspectives on database theory (context) - Yannakakis - 1995
19 the complexity of database queries (context) - Papadimitriou, Yannakakis - 1997
7 The Complexity of Decision Problems in Automata Theory (context) - Stockmeyer - 1974
6 Reducibilities among combinatorial problems (context) - Karp - 1972
Documents on the same site (http://www.math.uic.edu/~grohe/pub.html): More
Canonization for ...-Equivalence is Hard - Grohe (Correct)
On Fixed-Point Logic With Counting - Flum, Grohe (1998) (Correct)
Definability and Descriptive Complexity on Databases of.. - Grohe, Mariño (1999) (Correct)
Online articles have much greater impact More about CiteSeer.IST Add search form to your site Submit documents Feedback
CiteSeer.IST - Copyright Penn State and NEC