scholarly journals Experimenting with recursive queries in database and logic programming systems

2008 ◽  
Vol 8 (2) ◽  
pp. 129-165 ◽  
Author(s):  
G. TERRACINA ◽  
N. LEONE ◽  
V. LIO ◽  
C. PANETTA
Keyword(s):  
Database Management ◽  
State Of The Art ◽  
Database Systems ◽  
Database Management Systems ◽  
Main Memory ◽  
Management Systems ◽  
Distributed Data ◽  
Complex Reasoning ◽  
Programming Systems ◽  
New System

AbstractThis article considers the problem of reasoning on massive amounts of (possibly distributed) data. Presently, existing proposals show some limitations: (i) the quantity of data that can be handled contemporarily is limited, because reasoning is generally carried out in main-memory; (ii) the interaction with external (and independent) Database Management Systems is not trivial and, in several cases, not allowed at all; and (iii) the efficiency of present implementations is still not sufficient for their utilization in complex reasoning tasks involving massive amounts of data. This article provides a contribution in this setting; it presents a new system, called DLVDB, which aims to solve these problems. Moreover, it reports the results of a thorough experimental analysis we have carried out for comparing our system with several state-of-the-art systems (both logic and databases) on some classical deductive problems; the other tested systems are LDL++, XSB, Smodels, and three top-level commercial Database Management Systems. DLVDB significantly outperforms even the commercial database systems on recursive queries.

scholarly journals Exploiting Database Management Systems and Treewidth for Counting

2021 ◽  
pp. 1-30
Author(s):  
JOHANNES K. FICHTE ◽  
MARKUS HECHER ◽  
PATRICK THIER ◽  
STEFAN WOLTRAN
Keyword(s):  
Database Management ◽  
State Of The Art ◽  
Database Management Systems ◽  
Main Memory ◽  
Management Systems ◽  
Boolean Formula ◽  
Counting Problems ◽  
Counting Problem ◽  
Bounded Treewidth ◽  
Natural Approach

Abstract Bounded treewidth is one of the most cited combinatorial invariants in the literature. It was also applied for solving several counting problems efficiently. A canonical counting problem is #Sat, which asks to count the satisfying assignments of a Boolean formula. Recent work shows that benchmarking instances for #Sat often have reasonably small treewidth. This paper deals with counting problems for instances of small treewidth. We introduce a general framework to solve counting questions based on state-of-the-art database management systems (DBMSs). Our framework takes explicitly advantage of small treewidth by solving instances using dynamic programming (DP) on tree decompositions (TD). Therefore, we implement the concept of DP into a DBMS (PostgreSQL), since DP algorithms are already often given in terms of table manipulations in theory. This allows for elegant specifications of DP algorithms and the use of SQL to manipulate records and tables, which gives us a natural approach to bring DP algorithms into practice. To the best of our knowledge, we present the first approach to employ a DBMS for algorithms on TDs. A key advantage of our approach is that DBMSs naturally allow for dealing with huge tables with a limited amount of main memory (RAM).

A Framework for Cost-Based Query Optimization in Native XML Database Management Systems

2010 ◽  
pp. 160-183 ◽  
Author(s):  
Andreas M. Weiner ◽  
Theo Härder
Keyword(s):  
Query Optimization ◽  
Database Management ◽  
Cost Model ◽  
Database Systems ◽  
Database Management Systems ◽  
Management Systems ◽  
Xml Database ◽  
Xml Documents ◽  
Native Xml Database ◽  
Query Optimizers

Since the very beginning of query processing in database systems, cost-based query optimization has been the essential strategy for effectively answering complex queries on large documents. XML documents can be efficiently stored and processed using native XML database management systems. Even though such systems can choose from a huge repertoire of join operators (e. g., Structural Joins and Holistic Twig Joins) and various index access operators to efficiently evaluate queries on XML documents, the development of full-fledged XML query optimizers is still in its infancy. Especially the evaluation of complex XQuery expressions using these operators is not well understood and needs further research. The extensible, rule-based, and cost-based XML query optimization framework proposed in this chapter, serves as a testbed for exploring how and whether well-known concepts from relational query optimization (e. g., join reordering) can be reused and which new techniques can make a significant contribution to speed-up query execution. Using the best practices and an appropriate cost model that will be developed using this framework, it can be turned into a robust cost-based XML query optimizer in the future.

State of the Art Technology

2013 ◽  
pp. 201-218
Author(s):  
Ibrahim Dweib ◽  
Joan Lu
Keyword(s):  
Database Management ◽  
Relational Databases ◽  
State Of The Art ◽  
Database Management Systems ◽  
The State ◽  
Sql Server ◽  
Management Systems ◽  
Advantages And Disadvantages ◽  
Xml Documents

This chapter presents the state of the art approaches for storing and retrieving the XML documents from relational databases. Approaches are classified into schema-based mapping and schemaless-based mapping. It also discusses the solutions which are included in Database Management Systems such as SQL Server, Oracle, and DB2. The discussion addresses the issues of: rebuilding XML from RDBMS approaches, comparison of mapping approaches, and their advantages and disadvantages. The chapter concludes with the issues addressed.

Highly Available Database Management Systems

2009 ◽  
pp. 28-34
Author(s):  
Wenbing Zhao
Keyword(s):  
Database Management ◽  
Database Systems ◽  
Database Management Systems ◽  
High Availability ◽  
Management Systems ◽  
Database Replication ◽  
The Subject ◽  
Database Clustering ◽  
Alternative Solutions

The subject of highly available database systems has been studied for more than two decades, and there exist many alternative solutions (Agrawal, El Abbadi, & Steinke, 1997; Kemme, & Alonso, 2000; Patino-Martinez, Jimenez-Peris, Kemme, & Alonso, 2005). In this article, we provide an overview of two of the most popular database high availability strategies, namely database replication and database clustering. The emphasis is given to those that have been adopted and implemented by major database management systems (Davies & Fisk, 2006; Ault & Tumma, 2003).

A Newly Proposed Cloud Computing Based Strengthen Distributed Database System Model and Its Applications in Database Modelling

2021 ◽  
Vol 9 (10) ◽  
pp. 442-449
Author(s):  
Shivankur Thapliyal
Keyword(s):  
Data Storage ◽  
Database Management ◽  
Large Data ◽  
Database Systems ◽  
Distributed Database ◽  
Database Management Systems ◽  
Management Systems ◽  
Data Sets ◽  
Distributed Database System ◽  
Distributed Database Management

Abstract: In the modern era of today’s exceptional Information age, the day to day transactions of huge sensitive data sets, which is in the form of PBs (Peta-Bytes) 250 bytes and YBs (Yotta – Bytes) 280 bytes are drastically increases with enormous speed on CLOUD data storage environment. CLOUDs data storage environment are one of the most superior and reliable platform for storing a large sets of data both at enterprise level or local level. Because CLOUD provides online data fetching capability to restore or fetching data at any geographical locations through login their correspondent credentials. But to enhancement or spread of these large data sets are becomes also very complex with respect to maintenance of these data with take concern of consistency and data security, because to maintain these large data sets with full of consistency and integrity are really a very typical and rational tasks, so here In this paper we proposed a distributed database management systems for CLOUD interface also preserves or to take concern data security features with full restoration of CIA (Confidentiality, Integrity, Availability or Authenticity) trade of Information Security. Here we also improvised the mechanisms of traditional distributed database management systems because the tendency to preserves information and recover ability after any misconceptions happens that we restore data which belongs to similar person may have to be stored at different locations, but this newly proposed distributed database systems architecture contains all information or record which belong to similar person are stored in one database rather restore it different databases but the location of these data have to be changes mean while that the content or data which resides in one databases have to be moved to some other database and also preserves the security features, and this model also have capability to run older traditional methodology based distributed database management systems using this model. So the detailed description about these models and communication infrastructure among different CLOUDs are append in the upcoming sections of this paper. Keywords: Cloud based Distributed Database system model, Distributed system, Distributed Database model of CLOUD, Cloud Distributed Database, CLOUD based database systems

scholarly journals Seasonality and Software Vulnerabilities in Major Database Management Systems

2020 ◽  
Vol 5 (12) ◽  
pp. 76-81
Author(s):  
HyunChul Joh
Keyword(s):  
Database Management ◽  
Database Systems ◽  
Database Management Systems ◽  
Sql Server ◽  
Management Systems ◽  
Security Risks ◽  
Oracle Database ◽  
Software Vulnerabilities ◽  
Security Effectiveness ◽  
Relational Database Management

Popularity and marketshare are very important index for software users and vendors since more popular systems tend to engage better user experience and environments. periodical fluctuations in the popularity and marketshare could be vital factors when we estimate the potential risk analysis in target systems. Meanwhile, software vulnerabilities, in major relational database management systems, are detected every now and then. Today, all most every organizations depend on those database systems for store and retrieve their any kinds of informations for the reasons of security, effectiveness, etc. They have to manage and evaluate the level of risks created by the software vulnerabilities so that they could avoid potential losses before the security defects damage their reputations. Here, we examine the seasonal fluctuations with respect to the view of software security risks in the four major database systems, namely MySQL, MariaDB, Oracle Database and Microsoft SQL Server.

scholarly journals Deriving Triggers from Integrity Constraint Specifications in the Database Management Systems

10.14311/286 ◽  
2001 ◽  
Vol 41 (6) ◽  
Author(s):  
M. Badawy ◽  
K. Richta
Keyword(s):  
Database Management ◽  
Database Systems ◽  
Database System ◽  
Database Management Systems ◽  
Integrity Constraints ◽  
Management Systems ◽  
Integrity Constraint ◽  
Simple Rules

Supporting integrity constraints is essential for database systems. Integrity constraints are used to ensure that the data in a database complies with rules that have been set to establish accurate and acceptable information for a database. Triggers provide a very powerful and flexible means to realize effective constraint enforcing mechanisms. Implementing triggers based on constraint specifications follows some simple rules that are basically independent of a particular commercial database system. This paper gives these rules, which can be used to derive triggers from constraint specifications. A comparison of advantages of constraints and triggers is also given in this paper.

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