Filters








24,627 Hits in 6.8 sec

Modeling View Selection as a Constraint Satisfaction Problem [chapter]

Imene Mami, Remi Coletta, Zohra Bellahsene
2011 Lecture Notes in Computer Science  
such as total view maintenance cost and/or storage space.  ...  This paper deals with the view selection issue, which consists in finding a set of views to materialize that minimizes the expected cost of evaluating the query workload, given a limited amount of resource  ...  Experiments under the maintenance cost and space constraints In order to compare the performance of the view selection methods in the context where both maintenance cost and space constraints exist, we  ... 
doi:10.1007/978-3-642-23091-2_33 fatcat:jqpfhq4kxfdmva6mgujn45ba44

Materialized view maintenance and integrity constraint checking

Kenneth A. Ross, Divesh Srivastava, S. Sudarshan
1996 Proceedings of the 1996 ACM SIGMOD international conference on Management of data - SIGMOD '96  
We investigate the problem of incremental maintenance of an SQL view in the face of database updates, and show that it is possible to reduce the total time cost of view maintenance by materializing (and  ...  Example 1.1 (Additional Materialized Views) Consider a corporate database with two relations: Dept (DName, MName, Budget), which gives the manager and budget for each department in the corporation, and  ...  grants IRI-9209029, CDA-90-24735, and by an NSF Young Investigator award.  ... 
doi:10.1145/233269.233361 dblp:conf/sigmod/RossSS96 fatcat:hqpez2bjjfe7lpxbb24seoidsa

View Selection under Multiple Resource Constraints in a Distributed Context [chapter]

Imene Mami, Zohra Bellahsene, Remi Coletta
2012 Lecture Notes in Computer Science  
Then, we propose a solution using constraint programming for modeling and solving the view selection problem under multiple resource constraints in a distributed context.  ...  In past research, the view selection issue has essentially been investigated in the centralized context. In this paper, we address the view selection problem in a distributed scenario.  ...  Constraints (8) and (9) insure that the best plan with the minimum cost is selected to maintain a view.  ... 
doi:10.1007/978-3-642-32597-7_25 fatcat:77p6xjdn4fdetm2tiyjz4fuubm

Materialized view maintenance and integrity constraint checking

Kenneth A. Ross, Divesh Srivastava, S. Sudarshan
1996 SIGMOD record  
We investigate the problem of incremental maintenance of an SQL view in the face of database updates, and show that it is possible to reduce the total time cost of view maintenance by materializing (and  ...  Example 1.1 (Additional Materialized Views) Consider a corporate database with two relations: Dept (DName, MName, Budget), which gives the manager and budget for each department in the corporation, and  ...  grants IRI-9209029, CDA-90-24735, and by an NSF Young Investigator award.  ... 
doi:10.1145/235968.233361 fatcat:brycahul5jaoxbulwlzfl6zqiu

Using global constraints for local search [chapter]

Alexander Nareyek
2001 Constraint Programming and Large Scale Discrete Optimization  
The use of global constraints for local search a l l o ws us to revise a current state on a more global level with domainspeci c knowledge, while preserving features like reusability and maintenance.  ...  Other approaches take the general constraint programming framework as a starting point and try to introduce local search methods for constraint satisfaction.  ...  selection, and one with random walks.  ... 
doi:10.1090/dimacs/057/02 dblp:conf/dimacs/Nareyek98 fatcat:35tybb7zzfhmnowtkq5zxl7pye

Using Global Constraints for Local Search [chapter]

2001 Lecture Notes in Computer Science  
The use of global constraints for local search a l l o ws us to revise a current state on a more global level with domainspeci c knowledge, while preserving features like reusability and maintenance.  ...  Other approaches take the general constraint programming framework as a starting point and try to introduce local search methods for constraint satisfaction.  ...  selection, and one with random walks.  ... 
doi:10.1007/3-540-45746-1_2 fatcat:e2nl2si56ffxbi4snbxv7vrtoq

Randomization in Constraint Programming for Airline Planning [chapter]

Lars Otten, Mattias Grönkvist, Devdatt Dubhashi
2006 Lecture Notes in Computer Science  
We extend the common depth-first backtrack search for constraint satisfaction problems with randomized variable and value selection.  ...  We analyze the performance impact of these extensions and, in order to exploit the improvements, add restarts to the search procedure.  ...  Acknowledgments We would like to thank the developers of Gecode, Christian Schulte, Guido Tack and Mikael Lagerkvist, for their constant willingness to answer our questions and their help with a number  ... 
doi:10.1007/11889205_30 fatcat:mamntkb4afckpakmusuguohy54

Using Relational Database Constraints to Design Materialized Views in Data Warehouses [chapter]

Taehee Lee, Jae-young Chang, Sang-goo Lee
2004 Lecture Notes in Computer Science  
The goal of the materialized view selection problem is to select an appropriate set of views that minimize total query response time as well as the view maintenance cost.  ...  The proposed candidate view space guarantees to find a polynomial bounded set of optimal views, and any selection algorithm from previous research, e.g. greedy algorithm, can be ran on the candidate view  ...  The materialized view selection problem is proven to be an NP-hard problem. Therefore, reducing the candidate view space is as important as developing the search heuristics.  ... 
doi:10.1007/978-3-540-24655-8_42 fatcat:jpht75a5mvdatpdwyu467sqefu

Materialized view selection under the maintenance time constraint

Weifa Liang, Hui Wang, Maria E. Orlowska
2001 Data & Knowledge Engineering  
In this paper the view selection problem under the maintenance time constraint is investigated. Two ecient, heuristic algorithms for the problem are proposed.  ...  The objective is to select an appropriate set of views that minimizes the total query response time with the constraint that the total maintenance time for these materialized views is within a given bound  ...  Yu for his helpful comments and suggestions about the proposed algorithms.  ... 
doi:10.1016/s0169-023x(01)00007-6 fatcat:bmwvsdnb3nbwpi3skkl5a55usi

Rolling Stock Rostering Optimization Under Maintenance Constraints

Giovanni Luca Giacco, Andrea D'Ariano, Dario Pacciarelli
2014 Journal of Intelligent Transportation Systems / Taylor & Francis  
In our formulation, a rostering solution is viewed as a minimal cost Hamiltonian cycle in a graph with service pairings, empty runs and short-term maintenance tasks.  ...  This is a key problem in railway rostering planning that requires to cover a given set of services and maintenance works with a minimum amount of rolling stock units.  ...  In conclusions, the rostering problem can be viewed as the problem of finding a minimum cost Hamiltonian cycle in G with additional constraints related to the implementation of maintenance tasks.  ... 
doi:10.1080/15472450.2013.801712 fatcat:tc4hsdp3pvadxh6az55dnrv43y

Algorithms for Constraint-Satisfaction Problems: A Survey

Vipin Kumar
1992 The AI Magazine  
A large number of problems in AI and other areas of computer science can be viewed as special cases of the constraint-satisfaction problem.  ...  Some examples are machine vision, belief maintenance, scheduling, temporal reasoning, graph problems, floor plan design, the planning of genetic experiments, and the satisfiability problem.  ...  Acknowledgments I want to thank Charles Petrie, Ananth Grama, and Francesco Ricci for a number of suggestions for improving the quality of this article.  ... 
doi:10.1609/aimag.v13i1.976 dblp:journals/aim/Kumar92 fatcat:vl552eebm5bxtnu3gkvre2v5ua

Constraint Satisfaction Approach on Product Configuration with Cost Estimation [chapter]

Lin Wang, Wee Keong Ng, Bing Song
2009 Lecture Notes in Computer Science  
In this thesis, an extended Dynamic Constraint Satisfaction Problem (DCSP) based product configuration and cost estimation system is proposed to to effectively represent the large amount of data with great  ...  Cost is a critical composition and criterion for product family design; however, the integration of cost estimation and product family design has not been successfully addressed.  ...  If there are more than one variables with the same number of such constraints, including there is no constraint, the selection is performed on FF heuristic; i.e., the variable with the smallest domain  ... 
doi:10.1007/978-3-642-02568-6_74 fatcat:o5o4oxss6fawtbvhg4mqbqyeue

A Constraint-Based Autonomous 3D Camera System

Owen Bourne, Abdul Sattar, Scott Goodwin
2007 Constraints  
This paper describes a novel application of constraint satisfaction in the design of a camera system that addresses the unique and difficult challenges of IDE.  ...  It demonstrates a specialized constraint solver that exploits the spatial structure of the problem, enabling the real-time use of the camera system.  ...  This shallow tree makes the application of backtracking and backjumping heuristics difficult, since the amount of pruning performed by such heuristics is minimal.  ... 
doi:10.1007/s10601-007-9026-8 fatcat:i65jdi5vh5ah7he76yilw2zd4e

Business Process Scheduling with Resource Availability Constraints [chapter]

Jiajie Xu, Chengfei Liu, Xiaohui Zhao, Sira Yongchareon
2010 Lecture Notes in Computer Science  
Most existing process scheduling and resource management approaches focus on process structure and resource utilisation, yet neglect the resource availability constraints.  ...  In this paper, we investigate how to plan the business process instances scheduling in accordance with resource availability patterns, so that enterprise resources can be rationally and sufficiently used  ...  The penalty of task candidates are evaluated according to the heuristic rules proposed above, and the resource slot is allocated to the task with minimal penalty from the global view.  ... 
doi:10.1007/978-3-642-16934-2_30 fatcat:2g5e6z6wnfeu5ohna4sovnnlzy

Constraint Programming in Structural Bioinformatics

Pedro Barahona, Ludwig Krippahl
2008 Constraints  
In this paper, we report the application of constraint programming to address two structural bioinformatics problems, namely protein structure prediction and protein interaction (docking).  ...  The efficient application of constraint programming requires innovative modelling of these problems, as well as the development of advanced propagation techniques (e.g. global reasoning and propagation  ...  The variable selection heuristic is a typical first-fail heuristic: select the atom with smallest domain, in this case the volume of the Good Region.  ... 
doi:10.1007/s10601-007-9036-6 fatcat:ymjcj6xi6vdc5gat6exmarg76y
« Previous Showing results 1 — 15 out of 24,627 results