Transcript CS F212: Database Systems - Computer Science & Information

CS F212: Database Systems
Today’s Class
 Course operational details
 Introduction
 overview of DBMS
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Course staff
Instructor-in-charge : YASHVARDHAN SHARMA ([email protected])
Lab Instructors
: Mohit Sati ([email protected])
Netika Gupta ([email protected])
Rupal Bhargva([email protected])
Group of Professional Assistants
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General Info.
• Course website: csis/faculty/yash
• Email: [email protected]
• Office Hrs: Thursday 4pm to 6pm @6120-I
• Text Book: Database System Concepts, 6th Ed, A. Silberschatz, H.F.
Korth and S. Sudarshan, 2011
http://www.db-book.com
http://www.mhhe.com/silberschatz
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Reference Books
• Ramakrishna R. & Gehrke J.
Database Management Systems, 3e, Mc-Graw Hill, 2003.
http://www/cs.wisc.edu/~dbbook
• Hector G Molina, Jeffrey D.Ullman & Jennifer Widom.
Database Systems – The Complete Book, Pearson Education, 2002.
Home Page:
http://www-db.stanford.edu/~ullman/dscb.html
• Elmarsi R, & Navathe S B.
Fundamental of Database System, 5e, Pearson Education, 2008.
http://www.aw.com/cssupport
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Course Salient features
• Emphasis on theoretical concepts and implementation
details
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Foundational concepts
ER-Modeling+Relational Model + Normalization
Query Language – RA, SQL
Application Development
Database System Implementation
Database design and tuning
• Structured labs & Programming Assignments
• MidSem Test-I[25%-50M]+Assignments[35%-70M]+ Compre[40%-80M]
= Total[100% -200M]
• Assignments scope:
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Project– 10 [Group]
Term Paper – 10 [Group]
Online Test – 40 [Individual]
Lab Attendance – 10 [Individual]
• Reading Assignments
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Why Study Databases??
?
• Simply fascinating
• Commercially very relevant !!
• DBMS encompasses most of CS
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OS, languages, theory, AI, multimedia, logic
• Significance of Databases with Internet
• Datasets increasing in diversity and volume.
• Numeric and Textual Databases
• Multimedia Databases
• Geographic Information Systems (GIS)
• Data warehousing, Data mining, Business Intelligence, DSS
• Digital libraries, interactive video, Human Genome project
• ... need for DBMS exploding
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Tsunami of Data
• Telecom data ( 4.6 bn mobile subscribers)
 There are 3 Billion Telephone Calls in US each day,
30 Billion emails daily, 1 Billion SMS, IMs.
 IP Network Traffic: up to 1 Billion packets per hour per router. Each ISP has many
(hundreds) routers!
• WWW
• Weblog data (160 mn websites)
• Email data
• Satellite imaging data
• Social networking sites data
• Genome data
• CERN’s LHC (15 petabytes/year)
Tsunami of Data
• No. of pics on Facebook

• 15 bn unique photos
• 60 bn photos stored (4 sizes)
Imageshack (20 bn)
• Photobucket (7.2 bn)
• Flickr (3.4 bn)
• Multiply (3 bn)
Biggest OLTP System
• SABRE
• Sabre is a computer reservations system/global
distribution system (GDS) used by airlines, railways,
hotels, travel agents and other travel companies
• Used by more than 200 airlines
What we Study in this course??
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• Foundations
• Data Models: ER, Relational Models
• Query languages : RA, SQL
• Design & Development
• Normalization, Application Development
• Efficiency & Scalability
• Indexing
• Query evaluation
• Concurrency & Robustness
• Transaction Management – concurrency, recovery
• Advanced Database Concepts – XML, Data
Warehousing, Data Mining, Big Data
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Big Names in Database Systems
Company Product
Oracle
IBM
Microsoft
Sybase
Informix
Oracle 8i, 9i, 10g,11g
DB2, Universal Server
Access, SQL Server-2008
Adaptive Server
Dynamic Server
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Who Needs Database Systems
Typical Applications:
Personnel management
Inventory and purchase order
Insurance policies and customer data
……
Corporate databases
Web data management
Typical Applications:
Web page management
Personalize web pages
……
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Examples of Database Applications
• Purchases from the supermarket
• Purchases using your credit card
• Booking a holiday at the travel agents
• Using the local library
• Taking out insurance
• Using the Internet
• Studying at university
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What is a Database, DBMS, Database Systems?
• A very large, integrated collection of structured
data.
• Gigabytes (230 or 109), Terabytes, Petabytes
• Models real-world enterprise.
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Entities (e.g., students, courses)
Relationships (e.g., Mohan is taking ISC332)
• A Database Management System (DBMS) is a
software package designed to store and manage
large databases with complex features.
• Goal : Store and Retrieve database information
conveniently and efficiently
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Basic Definitions
• Database System: The DBMS software together with the data
itself. Sometimes, the applications are also included.
database system
database
Application
DBMS
data
catalog
e.g., the student records database system
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Typical DBMS Functionality
• Define a database: in terms of data
types, structures and constraints
• Construct or Load the Database on a secondary
storage medium
• Manipulating the database: querying, generating
reports, insertions, deletions and modifications to its
content
• Concurrent Processing and Sharing by a set of users
and programs – yet, keeping all data valid and
consistent
• Other features:
DBMS
• Protection or Security measures to prevent
unauthorized access
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Relational DBMS
• Based on a paper by Ted Codd in 1970
• Queries could be expressed in a very high-level language, which greatly increases
the efficiency of DB programmers
• accountNo
balance
type
12345
1000.00
savings
67890
2846.92
checking
• SELECT balance FROM Accounts WHERE accountNo=67890;
• SELECT accountNo FROM Accounts WHERE type=‘savings’ AND balance<1200;
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What is in a Database?
• A database contains information about a particular
enterprise or a particular application.
• E.g., a database for an enterprise may contain everything
needed for the planning and operation of the enterprise:
customer information, employee information, product
information, sales and expenses, etc.
• You don’t have to be a company to use a database: you can
store your personal information, expenses, phone numbers
in a database (e.g., using Access on a PC).
• As a matter of fact, you could store all data pertinent to a
particular purpose in a database.
• This usually means that a database stores data that are
related to each other.
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Database Design
ARC database:
students: names, IDNO, PRNo, …
courses: course-no, course-names, …
classroom: number, location, …
SWD database:
db designer 1
BITS
db designer 2
classroom: number, location, …
office: number, location, …
faculty-residence: building-no, …
student-residence: room-no, …
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Is a database the same as a file?
• You can store data in a file or a set of files, but …
• How do you input data and to get back the data from the
files?
• A database is managed by a DBMS.
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Purpose of Database Management Systems (DBMS)
Database management systems were developed to
handle the difficulties caused by different people
writing different applications independently.
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Purposes of Database Systems
• A DBMS attempts to resolve the following problems:
• Data redundancy and inconsistency by keeping one copy of a data
item in the database
• Difficulty in accessing data by provided query languages and
shared libraries
• Data isolation (multiple files and formats)
• Integrity problems by enforcing constraints (age > 0)
• Atomicity of updates
• Concurrent access by multiple users
• Security problems
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Data Independence
• One big problem in application development is the
separation of applications from data
• Do I have changed my program when I …
• replace my hard drive?
• store the data in a b-tree instead of a hash file?
• partition the data into two physical files (or merge two physical
files into one)?
• store salary as floating point number instead of integer?
• develop other applications that use the same set of data?
• add more data fields to support other applications?
• ……
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Data Abstraction
• The answer to the previous questions is to introduce
levels of abstraction of indirection.
• Consider how do function calls allow you to change a
part of your program without affecting other parts?
Main
Program
functio
n
functio
n
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