Databases Presented by Trisha Cummings. Some basics What do databases do Quite simply they keep track of things What’s in a database Data are what we.

DatabasesPresented by Trisha Cummings

Some basics

What do databases do Quite simply they keep track of

things What’s in a database Data are what we call raw facts

or data No processing has been done to

them to give them meaning Information is the result of

processing raw data to reveal its meaning.

In our current “information age” we need accurate, relevant and timely information.

Such information is key to good decision making.

Data are the foundation of information.

Which is the bedrock to knowledge

Or the body of facts and information about any specific subject.

Data constitute the building blocks of information

Information is produced by processing data

Information reveals the meaning of data

Accurate, timely and relevant information is the key to good decision making

Good decision making is the key to survival for organizations

This requires Data Management which is simply the generation, storage and retrieval of data

Data management requires the use of a computer.

A database is a shared, integrated computer structure that stores a collection of End user data – raw facts of interest

to the end user Metadata – or data about data in

which the end user data is integrated and managed

The Database Management System –DBMS serves as an intermediary between the user and the database.

The data structure is stored as a collection of files and you get to them thru the DBMS

The DBMS presents the end user with a single integrate view of the data in the database.

Its hides the databases complexity from users

A DBMS advantages Improved data sharing Improved data security Better data integration Minimized data inconsistency Improved data access – thru

queries Requests to the DBMS for data

manipulation Or Ad Hoc – spur of the moment

queries Improved decision making Increased end user productivity

Kinds of databases

Single User Multiuser

Workgroup – smaller than 50 Enterprise – larger than 50

E-commerce Centralized – single site Distributed – several site

Operational database supports day to day operations – also called a transactional or production database

Data warehouse – stores data to generate strategic or tactical decisions

Types of Databases The Flat Model

Two dimensional The Hierarchical Model

Set up in a tree structure The Network Model

Records are stored with links to other records

The Relational Model Most popular and a very powerful tool Not just for storing data but also for

accessing it.

Database Design

In order to have an effective, productive database – good design is “mission critical”

Needs proper structure Proper relationships Appropriate constraints Design databaes from existing

data New Information Systems

Relational Databases

Is a database composed of related objects – primarily tables

Allows for data to be broken down into smaller, logical, and manageable units

One can still use a single query to retrieve data spread over multiple tables

This is achieved thru keys.

DATABASE ADMINISTRATORS

What is this job like? The Internet and electronic commerce (e-commerce)

generate lots of data. Computer databases that store information on

customers, inventory, and projects are found in nearly every industry.

Data must be stored, organized, and managed. Database administrators work with database

software to find ways to do this. They identify user needs, set up computer

databases, and test systems. They ensure that systems perform as they should

and add people to the system as needed. Database administrators often plan security

measures. Data integrity, backup, and security are critical parts of the job.

On a new system, you would work with an organization to: establish what the database is for, who will use it

and which other systems it will link to, for example telephony

plan its structure, showing how to organize the data (the 'back end' design), and how to find and display the information ('front end' usability)

build a test version and check the results to iron out technical problems, known as bugs

fill (populate) the database with new information or transfer existing data into it

draw up plans for updating information, creating back-up copies, reporting errors and putting in security measures.

What qualifications and experience will employers look for?

For most DBA jobs, you would need to know how to use structured query language (SQL) along with database management systems (DBMS), which include: RDBMS (relational database management

systems) OODBMS (object-oriented database management

systems) XML database management systems.

There are different ways to gain this knowledge but employers often look for previous experience in computing. This would normally be in the form of an IT support, programming or web development background.

Duties: The DBA must be able to work independently as well

as in a team environment. Develop data model describing data elements and

how they are used, following procedures and using pen, template or computer software.

Develop standards and guidelines to guide the use and acquisition of software and to protect vulnerable information.

Establish standards, criteria, and guidelines with respect to design implementation, testing and use of data for an office or department.

Modify existing databases and database management systems or direct programmers and analysts to make changes.

Plan, coordinate and implement security measures to safeguard information in computer files against accidental or unauthorized damage, modification or disclosure.

Examine and recommend for approval, procedures in database management system manuals for making changes to database.

Examine and recommend for approval, project requests describing database user needs to estimate time and cost required to accomplish project.

Review workflow charts developed by programmer analyst to understand tasks computer will perform, such as updating records.

Select and enter codes to monitor database performance and to create production database.

Specify users and user access levels for each segment of database.

Test programs or databases, correct errors and make necessary modifications.

Write and code logical and physical database descriptions and specify identifiers of database to management system or direct others in coding descriptions.

Approve, schedule, plan, and supervise the installation and testing of new products and improvements to computer systems, such as the installation of new databases.

Develop methods for integrating different products so they work properly together, such as customizing commercial databases to fit specific needs.

Identify and evaluate industry trends in database systems to serve as a source of information and advice for upper management.

Maintain and revise data dictionary.

Train users and answer questions.

Help users with problems. Work as part of a project team to

coordinate database development and determine project scope and limitations.

You may have extra duties like supervising technical support staff, training users and producing performance reports for IT managers.

In a senior position you would normally be responsible for strategic planning, information policy, budgets and managing client relationships.

Other IT professionals like analysts, programmers and IT project managers, would normally work closely with you on projects.

Educational needs Associate in Arts in Information

Systems Major Component

CIS 110 Computer Programming Design CIS 111

Introduction to Relational Database Management Systems CIS 155 UNIX Operating System CIS 175 Introduction to Networking CIS 210 Systems Analysis and Development CIS 212 System Modeling Theory CIS 219 Database Management Systems CIS 222 Computer Ethics CIS 242 C++ Programming CIS 276 SQL Programming CIS 209 Web Page Development I

Bachelors' Degree – all of the AS courses plus a Concentration in: Database Management

CIS 276 SQL Programming CIS 305 PL/SQL Programming CIS 434 Database Fundamentals I CIS 444 Database Fundamental II CIS 474 Data Warehousing CIS 499 Senior Seminar in Computer Information Systems

Software development companies also offer database certification programs. Examples include: Microsoft Certified Database

Administrator (MCDBA) Sybase Adaptive Enterprise Server

(Developer and Administrator pathways) Oracle PL/SQL Developer, and 9i and 10g

Administrator (Associate, Professional and Master levels)

IBM DB2 and Informix certification.

Resources http://portal.cuny.edu/cms/id/cuny/documents/jobposting/0

23097.htm http://www.bls.gov/k12/computers01.htm http://www.learndirect-advice.co.uk/helpwithyourcareer/job

profiles/profiles/profile779/ Database Processing – Fundamentals, Design, and

Implementation by David M Kroenke – 10th edition ©2006, published by Pearson Prentice Hall.

Teach yourself SQL in 24 hours –by Ronald R Plew and Ryan K. Stephens - 3rd edition - published by SAMS

Database Systems – Design, Implementation and Management – Peter Rob and Carlos Coronel – 8th edition – Thomson Course Technology

http://www.strayer.edu/campus_catalog/VA/all/alexandria/information_systems/associate_in_arts_in_information_systems

http://www.strayer.edu/campus_catalog/VA/all/alexandria/information_systems/BSIS