Database Fundamentals IS 422Lecture #1

Instructor: Dema Alorini

Database Fundamentals IS 422 Section: 7|1

Understand the basics of databases. Recognize the role of databases in different

organizations. Recognize the types database models. Use one of the real world database

management systems. Build database structure. Present logical solutions for solving different

problems. Demonstrate basic knowledge of the database

structure.

Course Goals

Database Fundamentals IS 422 Section: 7|1

Database: set of data (information) that is organized so it can be easily accessed, managed, and updated.

Data: a collection of facts Database includes data with different tables

tables contains columns called fields and rows called records data dements to be stored in each record.

Database Fundamentals IS 422 Section: 7|1

What is database?

Database Fundamentals IS 422 Section: 7|1

Query:

Retrieve the transcript ( a list of all courses and grades) of Smith.

Update:

Create a new section for the database course for this semester.

Manipulate data in database

Database Fundamentals IS 422 Section: 7|1

Definition: collection of programs that enables users to create and maintain a database.

Examples: - Oracle (the hardest)

- Microsoft SQL (Structured Query Language) Server - IBM DB2

Database Management System (DBMS)

Database Fundamentals IS 422 Section: 7|1

SELECT student_number FROM grade_reportResults: Student_Number

1717888

Example of SQL

Database Fundamentals IS 422 Section: 7|1

Keep data consistent Easy Access to data Easy data retrieval: using simple queries and reports

example: search for student name, list students with grades above 90, etc

Modify data: insert, delete, update content Multiple User Interfaces Restrict authorized access Storage for data Represent complex relationships among data Control Redundancy Backup and restore data

Why use a DBMS?

Database Fundamentals IS 422 Section: 7|1

Data Redundancy

A field that is repeated in two or more tables.

Database Fundamentals IS 422 Section: 7|1

Main costs of using a DBMS:

- High initial investment in hardware, software, training and possible need for additional hardware.

- Overhead for providing generality, security, recovery, integrity, and concurrency control.

- Generality that a DBMS provides for defining and processing data.

When a DBMS may be unnecessary:

- If the database and applications are simple, well defined, and not expected to change.

- If there are stringent real-time requirements that may not be met because of DBMS overhead.

- If access to data by multiple users is not required.

WHEN NOT TO USE A DBMS

Database Fundamentals IS 422 Section: 7|1

The DBMS software together with the data itself.

Database System

Database Fundamentals IS 422 Section: 7|1

Example of database Mini- world example: Part of a UNIVERSITY environment.

Data (entities):

- STUDENTs

- COURSEs

- SECTIONs (of COURSEs)

- (academic) DEPARTMENTs

- INSTRUCTORs

Relationships among data:

- SECTIONs are of specific COURSEs

- STUDENTs take SECTIONs

- COURSEs have prerequisite COURSEs

- INSTRUCTORs teach SECTIONs

- COURSEs are offered by DEPARTMENTs

- STUDENTs major in DEPARTMENTs

Database Fundamentals IS 422 Section: 7|1

Example (Continued)

Database Fundamentals IS 422 Section: 7|1

Structure of the record

STUDENT ( Name , Number, Class, Major)

COURSE ( Name , Number, Credit, Dept.)

Data type of data element

Name: a string of characters

Number: integer

Grade: {A,B,C,D,F,I}

Define the university database

Database Fundamentals IS 422 Section: 7|1

Database Administrators(DBAs): Responsible for managing the database system, authorizing access, coordinating & monitoring uses, acquiring resources.

Database designers are responsible for identifying the data to be stored in the database and for choosing appropriate structures to represent and store this data.

End Users: The persons that use the database for querying, updating, generating reports, etc.

Actors (Users)

Database Fundamentals IS 422 Section: 7|1

Define a database? In a database columns are called ....... In a database rows are called …… Database system is …….. Together with …. Users of database are 1. ……….2. ……….3. ………. List 3 advantages of using DBMS?

Questions?

Database Fundamentals IS 422 Section: 7|1

T/F1. A field that is repeated in two or more tables is

called data redundancy ( )2. End users are responsible for choosing structures to

represent data( )3. The main goal of using database is to organize

information in a way that it can be easily accesses ( )

4. DBMS provide multiple interfaces ( )5. Queries are used to manipulate data in database ( )6. A database design may be based on existing data (

)

Questions?