Nihan Kesim Çiçekli email: nihan@ceng.metu.edu.tr
URL: http://www.ceng.metu.edu.tr/~nihan/ceng302
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• Instructor: Nihan Kesim Çiçekli
•
Office: A308
• Email : nihan@ceng.metu.edu.tr
•
Lecture Hours: Tue. 10:40-11:30 (IE102);
Thu. 13:40-15:30 (IE102)
•
Course Web page: http://www.ceng.metu.edu.tr/~nihan/ceng302
•
Teaching Assistant:
Ali Anıl Sınacı
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1.
Raghu Ramakrishnan, Database Management
Systems, McGraw Hill, 3 rd edition, 2003 ( text book ).
2.
R. Elmasri, S.B. Navathe, Fundamentals of
Database Systems, 4 th edition, Addison-Wesley,
2004.
3.
A. Silberschatz, H.F. Korth, S. Sudarshan,
Database System Concepts, McGraw Hill, 4 th edition, 2002.
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• Assignments 20 %
• Midterm 1
25 %
• Midterm 2
• Final Exam
25 %
30 %
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• Policy on missed midterm:
– no make-up exam
• Lateness policy:
– Late assignments are penalized up to 10% per day.
• All assignments are to be your own work.
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• Introduction to Relational Database Management Systems
• The Relational Data Model
• Relational Algebra
• SQL
• QBE
• Entity-Relationship Model
• Relational Database Design: Normalization
• Secondary Storage Devices
• Sequential Files
• Indexed Sequential Files
• Hashing
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
A very large, integrated collection of data.

Models real-world enterprise.
– Entities (e.g., students, courses)
– Relationships (e.g., Tarkan is taking CENG302)

A Database Management System (DBMS) is a software package designed to store and manage databases.
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
Shift from computation to information
–
– at the “low end”: scramble to webspace (a mess!) at the “high end”: scientific applications

Datasets increasing in diversity and volume.
– Digital libraries, interactive video, Human Genome project, EOS project
– ... need for DBMS exploding

DBMS encompasses most of CS
–
OS, languages, theory, “AI”, multimedia, logic
?
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
Data independence and efficient access.

Reduced application development time.

Data integrity and security.

Uniform data administration.

Concurrent access, recovery from crashes.
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
A data model is a collection of concepts for describing data.

A schema is a description of a particular collection of data, using the given data model.

The relational model of data is the most widely used model today.
– Main concept: relation , basically a table with rows and columns.
– Every relation has a schema , which describes the columns, or fields.
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
Conceptual schema:
– Students(sid: string, name: string, login: string,
– age: integer, gpa:real)
Courses(cid: string, cname:string, credits:integer)
– Enrolled(sid:string, cid:string, grade:string)

Physical schema:
– Relations stored as unordered files.
– Index on first column of Students.

External Schema (View):
– Course_info(cid:string,enrollment:integer)
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Students ( sid : string, name: string, login: string, age: integer, gpa: real ) sid name
53666 Jones
53688 Smith
53650 Smith login jones@cs age gpa
18 3.4
smith@ee 18 3.2
smith@math 19 3.8
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 Many external schemata, single conceptual(logical) schema and physical schema .
– External schemata describe
– Conceptual schema defines logical structure
– Physical schema describes the files and indexes used.
External
Schema 1
External
Schema
2
External
Schema 3
Conceptual Schema
* Schemas are defined using DDL; data is modified/queried using DML
.
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
Applications insulated from how data is structured and stored.

Logical data independence: Protection from changes in logical structure of data.

Physical data independence: Protection from changes in physical structure of data.
* One of the most important benefits of using a DBMS!
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 A typical DBMS has a layered architecture.

This is one of several possible architectures; each system has its own variations.
These layers must consider concurrency control and recovery
Query Optimization and Execution
Relational Operators
Files and Access Methods
Buffer Management
Disk Space Management
DB
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