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.

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.

Algorithms, that implement set-theoretic operations on tables and multitables

2019 ◽  
Vol 33 ◽  
pp. 100-111
Author(s):  
Iryna Kanarskaya
Keyword(s):  
Database Management ◽  
Relational Databases ◽  
Database Management Systems ◽  
Management Systems ◽  
Actual Number ◽  
Average Case ◽  
Distribution Of Values ◽  
Processing Information ◽  
The Subject ◽  
Optimal Implementation

The paper is devoted to the research of algorithms implementing intersection, union and difference in tables and multitables. The subject of the work is relevant, since despite the importance and applicability of set-theoretical operations in relational databases, for some reason, the attention of researchers was focused on optimizing other table operations, first of all, the join. Meanwhile, the optimal implementation of set-theoretical operations will lead to a faster execution of the query, which containing at least one of set-theoretical operations, and will significantly reduce the time of processing information in the database management systems. For each set-theoretical operation algorithms that implement them on tables, in which strings are not repeat, and on multi-tables, in which the strings can be repeated, are considered. After that the modifications of the basic algorithms, that we found, which allow to significantly reduce the number of computations are considered. As an average case, we understand the most general case in which the domain of each attribute of the table schema is fixed and known above, and the distribution of values for each attribute in each table is uniform. For each of the six cases (three table operations and three multi-table operations), the fastest algorithms by this criterion were found. For all 6 algorithms considered on the tables (basic and fastest modifications of the basic ones) we found exact complexity on average. The found formulas defining the complexity of the proposed algorithms do not contain O-asymptotics. For the experimental confirmation of the results we developed the software system, which, for tables with given parameters, finds the actual number of computations performed for each of the proposed algorithms. The experiments carried out confirmed the theoretical estimates found for the tables and identified the fastest algorithms for the multitables. The results of the work can be used both in relational databases theory and in practice in queries optimization and to reduce the processing time in database management systems.

Integrity Issues in the Web

2002 ◽  
pp. 293-321 ◽  
Author(s):  
Jose F. Aladana Montes ◽  
Mariemma I. Yague del Valle ◽  
Antonio C. Gomez Lora
Keyword(s):  
Database Management ◽  
Relational Databases ◽  
Distributed Databases ◽  
Database Management Systems ◽  
Data Models ◽  
Management Systems ◽  
New Paradigm ◽  
File Management ◽  
Object Relational ◽  
The Web

Issues related to integrity in databases and distributed databases have been introduced in previous chapters. Therefore, the integrity problem in databases and how it can be managed in several data models (relational, active, temporal, geographical, and object-relational databases) are well known to the reader. The focus of this chapter is on introducing a new paradigm: The Web as the database, and its implications regarding integrity, i.e., the progressive adaptation of database techniques to Web usage. We consider that this will be done in a quite similar way to the evolution from integrated file management systems to database management systems.

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 Algorithmic and Software of Migration of Databases in Hypermarket Network

2020 ◽  
Vol 5 (2) ◽  
pp. 77-84
Author(s):  
Volodymyr Mruts ◽  
◽  
Marta Mashevska
Keyword(s):  
Database Management ◽  
Database Management Systems ◽  
Management Systems ◽  
Functional Requirements ◽  
Advantages And Disadvantages ◽  
The Common ◽  
Common Problems

Possible ways and options of migrating data from existing database management systems to new ones have been analyzed in the article. Also, the main advantages and disadvantages of these methods have been considered, the common problems that may arise during migration and the standard requirements for this type of system have been given. In the practical part, the Exact Transform Load (ETL) system has been developed with the implementation of all its functional and non-functional requirements, migrating data from the old system to the new one.

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 Storage organization for "open" sets of entity attributes in relational databases

2021 ◽  
Vol 12 (5-2021) ◽  
pp. 128-139
Author(s):  
Andrey G. Oleynik ◽  
Keyword(s):  
Information Systems ◽  
Relational Database ◽  
Database Management ◽  
Relational Databases ◽  
Database Management Systems ◽  
Management Systems ◽  
Two Dimensional ◽  
Open Set ◽  
Special Relations

Relations are practically implemented by database management systems in the form of two-dimensional tables. In this regard, certain difficulties arise in the development of relational database schemas, in which it is necessary to represent objects with an alterable (open) set of attributes. The article proposes a solution to this problem by including special relations in the scheme - relations of properties directory. Properties directory allow replenishing the sets of object attributes without changing the structure of the database. Examples of the practical use of properties directory in the development of database schemas of two information systems are presented.

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).

Sign in / Sign up

Export Citation Format

Share Document