16,027 research outputs found
A comparative analysis of data redundancy and execution time between relational and object oriented schema table
The design of database is one of the important parts in building software, because
database is the data storage inside the system. There are some techniques that allow
the programmer to improve design of the database. One of the most popular
techniques being used for database is the relational technique, which content entity
relationship diagram and normalization. The relational technique is easy to use and
useful for reducing data redundancy because the normalization technique solves the
data redundancy by applying normalization normal forms on the schema tables. The
second technique is the object oriented technique, which content class diagram and
generate schema table. An advantage of object oriented technique is its closeness to
programming languages like C++ or C#. This project is starting with applying
relational technique and object oriented technique to define which technique uses
less data redundancy during design database. Based on experimental results for total
data redundancy in HMS case study was 336 for relational technique and 364 for
object oriented technique as well as, course database case study was 186 for
relational technique and 204 for object oriented technique. Also, this project is focus
on query execution time between relational databases and object oriented database by
using user friendly window. The experimental result for query execution time in
HMS case study was 107.25 milliseconds for RDBMS and 80.5 milliseconds for
OODBMS. In course database case study was 46.75 milliseconds for RDBMS and
31.75 milliseconds for OODBMS. However, the comparative analysis in this project
is explaining the result of comparison between relational and object oriented
techniques specifically with data redundancy and query execution time
О топологии путей нормализации в реляционном каркасе
Исследованы пути нормализации в универсальном каркасе реляционных баз данных (БД) и топологии этих путей. Доказана теорема замкнутости путей нормализации в реляционном каркасе. Теорема позволяет применять реляционный каркас как уникальный носитель схем БД, нормализованных до высоких форм, а также анализировать существующие и внедренные БД на предмет их аномалий и влияния на приложения в процессе эксплуатации.Досліджено шляхи нормалізації в універсальному каркасі реляційних баз даних (БД) і топологію цих шляхів. Доведено теорему замкненості шляхів нормалізації в реляційному каркасі. Теорема дозволяє використовувати реляційний каркас в якості універсального носія схем БД, нормалізованих до високих форм, а також аналізувати існуючі та впроваджені БД на предмет їх аномалій та впливу на програмне застосування в процесі експлуатації.In the normalization ways in the universal frame of the relational databases and the topology of these ways are investigated. Theorem about closure of normalization ways in a relational frame has been proved. The theorem allows using a relational frame as a unique database schemes carrier, normalized to the higher forms. It also allows analyzing the existing and embedded databases for their anomalies and the impact on the software usage during the operation
Analysis of the Impact of Data Normalization on Cyber Event Correlation Query Performance
A critical capability required in the operation of cyberspace is the ability to maintain situational awareness of the status of the infrastructure elements that constitute cyberspace. Event logs from cyber devices can yield significant information, and when properly utilized they can provide timely situational awareness about the state of the cyber infrastructure. In addition, proper Information Assurance requires the validation and verification of the integrity of results generated by a commercial log analysis tool. Event log analysis can be performed using relational databases. To enhance database query performance, previous literatures affirm denormalization of databases. Yet database normalization can also increase query performance. Database normalization improved the majority of the queries performed using very large data sets of router events. In addition, queries performed faster on normalized tables when all the necessary data were contained in the normalized tables. Database normalization improves table organization and maintains better data consistency than a lack of normalization. Nonetheless, there are some tradeoffs when normalizing a database, such as additional preprocessing time and extra storage requirements. But overall, normalization improved query performance and must be considered an option when analyzing event logs using relational databases. There are three primary research questions addressed in this thesis: (1) What standards exist for the generation, transport, storage, and analysis of event log data for security analysis?; (2) How does database normalization impact query performance when using very large data sets (over 30 million) of router events?; and (3) What are the tradeoffs between using a normalized versus non-normalized database in terms of preprocessing time, query performance, storage requirements, and database consistency
Optimizing Federated Queries Based on the Physical Design of a Data Lake
The optimization of query execution plans is known to be crucial
for reducing the query execution time. In particular, query optimization
has been studied thoroughly for relational databases
over the past decades. Recently, the Resource Description Framework
(RDF) became popular for publishing data on the Web. As
a consequence, federations composed of different data models
like RDF and relational databases evolved. One type of these
federations are Semantic Data Lakes where every data source is
kept in its original data model and semantically annotated with
ontologies or controlled vocabularies. However, state-of-the-art
query engines for federated query processing over Semantic Data
Lakes often rely on optimization techniques tailored for RDF. In
this paper, we present query optimization techniques guided
by heuristics that take the physical design of a Data Lake into
account. The heuristics are implemented on top of Ontario, a
SPARQL query engine for Semantic Data Lakes. Using sourcespecific
heuristics, the query engine is able to generate more efficient
query execution plans by exploiting the knowledge about
indexes and normalization in relational databases. We show that
heuristics which take the physical design of the Data Lake into
account are able to speed up query processing
Using a Semi-Realistic Database to Support a Database Course
A common problem for university relational database courses is to construct effective databases for instructions and assignments. Highly simplified ‘toy’ databases are easily available for teaching, learning, and practicing. However, they do not reflect the complexity and practical considerations that students encounter in real-world projects after their graduation. On the other hand, production databases may contain too much domain nuances and complexity to be effectively used as a learning tool. Sakila is a semi-realistic, high quality, open source, and highly available database provided by MySQL. This paper describes the use of Sakila as a unified platform to support instructions and multiple assignments of a graduate database course for five semesters. Based on seven surveys with 186 responses, the paper discusses our experience using Sakila. We find this approach promising, and students in general find it more useful and interesting than the highly simplified databases developed by the instructor, or obtained from textbooks. We constructed a collection of 124 problems with suggested solutions on the topics of database modeling and normalization, SQL query, view, stored function, stored procedure, trigger, database Web-driven application development with PHP/MySQL, Relational Algebra using an interpreter, Relational Calculus, XML generation, XPath, and XQuery. This collection is available to Information Systems (IS) educators for adoption or adaptation as assignments, examples, and examination questions to support different database courses
Fast and Simple Relational Processing of Uncertain Data
This paper introduces U-relations, a succinct and purely relational
representation system for uncertain databases. U-relations support
attribute-level uncertainty using vertical partitioning. If we consider
positive relational algebra extended by an operation for computing possible
answers, a query on the logical level can be translated into, and evaluated as,
a single relational algebra query on the U-relation representation. The
translation scheme essentially preserves the size of the query in terms of
number of operations and, in particular, number of joins. Standard techniques
employed in off-the-shelf relational database management systems are effective
for optimizing and processing queries on U-relations. In our experiments we
show that query evaluation on U-relations scales to large amounts of data with
high degrees of uncertainty.Comment: 12 pages, 14 figure
Kolmogorov Complexity in perspective. Part II: Classification, Information Processing and Duality
We survey diverse approaches to the notion of information: from Shannon
entropy to Kolmogorov complexity. Two of the main applications of Kolmogorov
complexity are presented: randomness and classification. The survey is divided
in two parts published in a same volume. Part II is dedicated to the relation
between logic and information system, within the scope of Kolmogorov
algorithmic information theory. We present a recent application of Kolmogorov
complexity: classification using compression, an idea with provocative
implementation by authors such as Bennett, Vitanyi and Cilibrasi. This stresses
how Kolmogorov complexity, besides being a foundation to randomness, is also
related to classification. Another approach to classification is also
considered: the so-called "Google classification". It uses another original and
attractive idea which is connected to the classification using compression and
to Kolmogorov complexity from a conceptual point of view. We present and unify
these different approaches to classification in terms of Bottom-Up versus
Top-Down operational modes, of which we point the fundamental principles and
the underlying duality. We look at the way these two dual modes are used in
different approaches to information system, particularly the relational model
for database introduced by Codd in the 70's. This allows to point out diverse
forms of a fundamental duality. These operational modes are also reinterpreted
in the context of the comprehension schema of axiomatic set theory ZF. This
leads us to develop how Kolmogorov's complexity is linked to intensionality,
abstraction, classification and information system.Comment: 43 page
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