Lecture 1: Overview of CSCI 485 Notes: I presented parts of this lecture as a keynote at Educator’s Symposium of OOPSLA Shahram Ghandeharizadeh Director of USC Database Lab Computer Science Department University of Southern California

Logistics Required text book: Pre-req for the course: Database System Concepts, Silberschatz, Korth & Sudarshan, 6th Edition. Available in the bookstore. Please start to read Chapter 7 and Sections 2.1 to 2.3 for the next lecture Pre-req for the course: CS201: Data Structures Knowledge of an object-oriented programming language such as C++, Java, C#

Instructor Details Dr. Shahram Ghandeharizadeh Office: SAL 208 E-mail: shahram@usc.edu Phone: 213-740-4781 Office Hours: Wed: 10:30 to 11:30 am Mon: 11:30 to 12:30 pm Class URL: http://dblab.usc.edu/csci485

TA Details Sumita Barahmand Office: SAL 229 E-mail: barahman@usc.edu Office Hours: Mon: 1:30 to 3:30 pm

Outline Motivation for DBMS An outline for the course material Grading: Assignments and projects

Database Management Systems (DBMS) Used almost on a daily basis for either individual or business use. Relational database vendors were one of the fastest growing sectors during the .COM boom!

DATABASE & DBMS Database: An integrated collection of data, usually stored on secondary storage, typically describing the activities of one or more related organizations. Database management system (DBMS): A collection of software/programs designed to assist in maintaining and utilizing large collections of data.

BEFORE DBMS User 1 Data Data User 2 Application programs

AFTER DBMS User 1 DBMS User 2 Application programs Data managed by DBMS DBMS User 2 Application programs

WHY A DBMS? Reduced application development time Data independence: Application programs not dependent on data representation and storage details Data sharing: data is better utilized (discovered and reused), redundancy of data is minimized Data integrity and consistency: one may enforce consistency constraints on data, e.g., number of seats sold ≤ number of seats on the plane × 1.1 Centralized control: DBA tunes the database to balance user's needs Security: mechanisms to prevent unauthorized access. These mechanisms are based on content instead of file-oriented approach. Concurrency control: avoids undesirable race conditions that arise with simultaneous access/updates to data Crash recovery: ensures the integrity of data in the presence of failures

DBMS ARCHITECTURE … User 1 DBMS DB User n Physical data Conceptual schema

Data Models Conceptual Logical Physical

Build a database to keep the medical records of U.S. residents Data Models (Example) Build a database to keep the medical records of U.S. residents 13

Data Models Conceptual Logical Physical 14

Challenges Conceptual Logical Physical Abstraction, Inheritance, Encapsulation Conceptual Reduction to tables with minimal: data duplication, potential for data loss and update anomalies Logical Effective use of a DBMS, management of mismatch between tables and OO constructs, Index structures, CC & Crash recovery, Optimization techniques Physical

Challenges Conceptual Logical Physical E-R data model 5 Normal Forms Relational Data model, SQL, Relational Algebra Logical Different kinds of storage, A DBMS architecture, Index structures, CC & Crash recovery, Optimization techniques, Techniques to build a DBMS Physical

Relational DBMS Why? Performance! Reduced application development time Use of SQL makes access to data more uniform: Software modularity, Extensibility

Challenge 2 Two ways to teach this course: How to implement a DBMS? Protocols to realize atomic property of transactions How to use a DBMS? Setup a web server with a database and build a shopping bag Key difference: discussion at both the logical and physical levels Both require use of OO constructs

Grading Midterm 1: 35% Midterm 2: 35% Assignments: 30% First assignment is posted on the web. Due at noon on Thu, Jan 20.

Assignments (30%) Social networking sites: Visit rays.shorturl.com and sign-up. Conceptualize and understand RAYS’s functionality. Homework 1: Write a description of the RAYS and its functionality. Homework 2: Draw the ER diagram for the web site. Homework 3: Reduce the solution provided for Homework 2 into a collection of tables. Homework 4: Write SQL queries to implement functionalities of RAYS.