Jemerson Pedernal

IT 2.1FUNDAMENTALS OF DATABASE

APPLICATIONS

by PEDERNAL, JEMERSON G.

[BS-Computer Science]Palawan State University Computer Network Specialist

Jemerson Pedernal

Chapter 1Databases and Information Models

• 1.1 What is a database?• 1.2 What is a database management system?• 1.3 Introduction to information models and

data models • 1.4 Types of information models• 1.5 Typical roles and career path for database

professionals

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• Data is one of the most critical assets of any business.

• Data, as important as it is, needs robust, secure, and highly available software that can store and process it quickly.

• Database software usage is pervasive, yet it is taken for granted by the billions of daily users worldwide.

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1.1 Database

• A database is a repository of data, designed to support efficient data storage, retrieval and maintenance.

• A database may be specialized to store binary files, documents, images, videos, relational data, multidimensional data, transactional data, analytic data, or geographic data to name a few.

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1.2 Database Management System

• database management system, or simply DBMS, is a set of software tools that control access, organize, store, manage, retrieve and maintain data in a database.

• In practical use, the terms database, database server, database system, data server, and database management systems are often used interchangeably.

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1.3 Introduction to information models and data models

• An information model is an abstract, formal representation of entities that includes their properties, relationships and the operations that can be performed on them.

• The primary motivation behind the concept is to formalize the description of a problem domain without constraining how that description will be mapped to an actual implementation in software.

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• Modeling allows for compatibility with its predecessor models and has provisions for future extensions.

• An Information Model should hide all protocol and implementation details.

• An Information Model defines relationships between managed objects

• A data model is the blueprint of any database system.

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Figure 1.1 - Relationship between an Information Model and a Data Model

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1.4 Types of information models • Information model proposals can be split into nine historical epochs:

• Network (CODASYL): 1970’s • Hierarchical (IMS): late 1960’s and 1970’s • Relational: 1970’s and early 1980’s • Entity-Relationship: 1970’s • Extended Relational: 1980’s • Semantic: late 1970’s and 1980’s • Object-oriented: late 1980’s and early 1990’s • Object-relational: late 1980’s and early 1990’s • Semi-structured (XML): late 1990’s to the present

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Network Model

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Hierarchical model

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Relational model

• It has a solid mathematic foundation based on sets theory and predicate calculus and is the most used data model for databases today.

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Entity-Relationship model• Entities are objects that have an existence independent of any other

entities in the database.• Entities have attributes, which are the data elements that characterize the

entity.• One or more of these attributes could be designated to be a key. • Lastly, there could be relationships between entities. • Relationships could be 1-to-1, 1-to-n, n-to-1 or m-to-n, depending on how

the entities participated in the relationship. • Relationships could also have attributes that described the relationship.

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• Rather than being used as a model on its own, the E-R model has found success as a tool to design relational databases.

• In addition, it was a simple process to convert an E-R diagram into a collection of tables in third normal form.

• Today, the ability to create E-R diagrams are incorporated into data modeling tools such as IBM InfoSphere™ Data Architect.

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Object-relational model

• The Object-Relational (OR) model is very similar to the relational model;

• however, it treats • every entity as an object (instance of a class), and a

relationship as an inheritance.

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Other data models

• XML is ideal to store semi-structured data. • Object oriented data models are popular in

universities, but have not been widely accepted in the industry; l to store semi-structured data.

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1.5 Typical roles and career path for database professionals

• Data Architect• Database Architect• Database Administrator (DBA)• Application Developer

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Data Architect

• A data architect is responsible for designing an architecture that supports the organization's existing and future needs for data management.

• The architecture should cover databases, data integration and the means to get to the data.

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Database Architect• A database architect is responsible for the following activities:

• Gather and document requirements from business users and management and address them in a solution architecture.

• Share the architecture with business users and management.

• Create and enforce database and application development standards and processes.

• Create and enforce service level agreements (SLAs) for the business, specially addressing high availability, backup/restore and security.

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• Study new products, versions compatibility, and deployment feasibility and give recommendations to development teams and management.

• Understand hardware, operating system, database system, multi-tier component architecture and interaction between these components.

• Prepare high-level documents in-line with requirements.

• Review detailed designs and implementation details.

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Database Administrator (DBA)

• A database administrator (DBA) is responsible for the maintenance, performance, integrity and security of a database.

• Additional role requirements are likely to include planning, development and troubleshooting.

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Application Developer• A database application developer is a person in charge of

developing applications that access databases.• An application developer requires knowledge of the following: • Integrated database application development

environments (IDEs). • Database plug-ins for IDEs. • SQL development tools • Database performance monitoring and debugging • Application server environments, application deployment,

application performance monitoring and debugging

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SummaryIn this chapter, we discussed several database fundamental concepts

starting with simple definitions of a database and extending to a database management system.

Then, we discussed information and data models such as the network, hierarchical, and relational models.

At the end of the chapter, various roles associated with the database domain were discussed.