Dr. Ahmed's DBMS Lecture Notes: Introduction to Database Systems

These lecture notes, presented by Dr. Ahmed Mohamed Abd-Elwahab from Helwan University's BIS Department, offer a comprehensive introduction to Database Management Systems (DBMS). The notes begin with an outline covering fundamental concepts such as introduction, basic definitions, the purpose and advantages of database systems, and their applications. The first part concludes with discussions on file processing systems and the main characteristics of database systems. The second part delves into data abstraction, explaining the different levels (physical, logical, and view), instances, and schemas. It then explores various data models, including relational, entity-relationship, object-based, and semi-structured models. The notes also touch on database design, data storage, querying, transaction management, data mining, information retrieval, and the classification of DBMS based on data models, user numbers, and distribution (centralized, distributed, homogeneous, and heterogeneous systems). The lecture notes provide a detailed overview of DBMS concepts and their practical applications.

Lectures Notes in
Database Management Systems
Lecture (2)
Submitted By:
Dr. Ahmed Mohamed Abd-Elwahab
Lecture in BIS Department,
Faculty of Commerce & Business Administration,
Helwan University, Cairo, Egypt.

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Ch 1. Introduction to DBMS
OUTLINE (Part One)
❑ Introduction.
❑ Basic Definitions.
❑ Purpose of Database Systems.
❑ Disadvantages of the File Processing Systems.
❑ Main Characteristics (Advantages) of the Database Sy
❑ Database Systems Applications.

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لكشب تانايبال نيزختمظنموترمب
تانايبال عاجرتساةعرسبوةلوهسوقدة

Flat File Environment
File Processing Database System

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CHAPTER (1) Cont.
Introduction to DBMS

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Ch 1. OUTLINE (Part Two)
❑ Data Abstraction.
❑ Instances and Schemas.
❑ Data Models Categories.
❑ Database Design.
❑ Data Storage and Querying.
❑ Transaction Management.
❑ Data Mining & Information Retrieval.
❑ Classification of DBMS.

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1.6 Data Abstraction
Forthe System to be usable,it mustretrieve data
efficiently.The need for efficiency has led designers
use Complex data structures to represent data
database.Since many database systems users are no
computertrained,developershide the Complexity
from users through SeveralLevels ofAbstraction,to
simplify Users'interactions with the System.
al user mesh sh8l balo b 7aga
lma al klam bta3 al mibile yakmle al klam ale ana ktbah

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Data Abstraction in DBMS is a
Processof hidingirrelevant
detailsfrom Users.Because
database systemsare made of
Complex data structures.so,it
makes accessiblethe user
interaction with the database.

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1.6 Data Abstraction
The Three Levels of Data Abstraction:
describe how to storage data
nahtm bl data nafsha wl reltion ships

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1.6 Data Abstraction
1.Physical Level:
The Lowest-Level of abstraction describ
➢ How the data are actually Stored.
➢ Complex low-level data structures in de