INFS614, Dr. Brodsky, GMU1 Database Management Systems INFS 614 Instructor: Professor Alex Brodsky Lecture One - Introduction

INFS614, Dr. Brodsky, GMU2 Outline v Course syllabus –Course Schedule –Homework & project & exams v Satisfaction of prerequisites –Signed form must be submitted TODAY v Break (long) v Introduction to DB & DBMS –Outline of the entire course material

INFS614, Dr. Brodsky, GMU3 Class Schedule

INFS614, Dr. Brodsky, GMU4 Front matters v Always use as the first means to communicate with me! I will try to reply v Sign up for your Mason account. You may forward all your Mason s to your favorite address. v Required Book: –Database Management Systems, 3rd ed. by Raghu Ramakrishnan & Johannes Gehrke, McGraw-Hill. v Recommended Book: –Oracle 9i Programming: a Primer, by Rajshkhar Sunderraman, Addison Wesley, ISBN (or later versions) v On-Line Course Resources: –You are required to read all the material there. The content will be updated frequently. So check the web site periodically, at least once every week, and every time before class!

INFS614, Dr. Brodsky, GMU5 Submission and Grading v Late submission allowed up to one week (unless disallowed explicitly) but with 5% penalty each day. v On-time: within 5 minutes after the class begins. v Faxed-in submission accepted ( , attention to instructor) v The final grades assigned to the students are based on their performance on –homework assignments (15%) –midterm exam (32%), and –final exam (46%) and –a semester-long project (7%). v “Absolute” grade guarantees: 90+ A, 75+ B, 60+ C

INFS614, Dr. Brodsky, GMU6 Honor Code System v GMU honor Code v For this class –Homework & project are all individual. Group discussions are encouraged but final solution and write up must be individual. –Exams: individual effort, closed books v Satisfaction of prerequisites Form –Signed with honor code invoked.

INFS614, Dr. Brodsky, GMU7 Useful links for your computing needs v (especially the "Technical Info" section) for mason account information. v for ITE computing lab and Oracle DBMS information. v ml?persed.html for personal edition of Oracle 9i. ml?persed.html

INFS614, Dr. Brodsky, GMU8 Satisfaction of prerequisites v Prerequisites –INFS501 (Discrete mathematics) –INFS515 (Computer architecture/organization) –INFS590 (Programming with data structures) v For IS/SWE/ISA students –Satisfaction = foundation requirements are all satisfied. Check letter of admission for foundation requirements. –Student signs the form. v For other students –Satisfaction = talk to instructor and instructor agrees. –Instructor signs the form. v The SoP form must be signed in order to receive a grade for the course.

INFS614, Dr. Brodsky, GMU9 Break Talk to Non-IS/SWE/ISA students about their prerequisites

INFS614, Dr. Brodsky, GMU10 What are Database and DBMS? v Database: –A very large, integrated collection of data. –Data integrity is a concern. –Models real-world enterprise. u Entities (e.g., students, courses) u Relationships (e.g., Frodois taking INFS614) v A Database Management System (DBMS) is a software package designed to store, provide access and manage databases.

INFS614, Dr. Brodsky, GMU11 Why Use a DBMS? Easier and More Efficient v Data independence and efficient access. v Reduced application development time. v Data integrity and security. v Uniform data administration. v Concurrent access, recovery from crashes.

INFS614, Dr. Brodsky, GMU12 Data Models v A data model is a collection of concepts for describing data. v A schema is a description of a particular collection of data, using the a given data model. v 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.

INFS614, Dr. Brodsky, GMU13 Levels of Abstraction v Many views, single conceptual (logical) schema and physical schema. – Views describe how users see the data. – Conceptual schema defines logical structure – Physical schema describes the files and indexes used. * Schemas are defined using DDL; data is modified/queried using DML. Physical Schema Conceptual Schema View 1View 2View 3

INFS614, Dr. Brodsky, GMU14 Data Independence v Applications insulated from how data is structured and stored. v Logical data independence : Protection from changes in logical structure of data. v Physical data independence : Protection from changes in physical structure of data. * One of the most important benefits of using a DBMS!

INFS614, Dr. Brodsky, GMU15 Transaction v An execution of a DB program v Key concept is transaction, which is an atomic sequence of database actions (reads/writes). v ACID properties –A – Atomicity –C – Consistency –I – Isolation –D – Durability v How: log and concurrency control sub-system

INFS614, Dr. Brodsky, GMU16 Database Users v End users (or DB application users) v DB application programmers (more precisely, they are DBMS users) – E.g. smart webmasters – This course is mostly to learn how to (start to) be a DB application programmer. v Database administrator (DBA) – Designs logical /physical schemas – Handles security and authorization – Data availability, crash recovery – Database tuning as needs evolve Must understand how a DBMS works!

INFS614, Dr. Brodsky, GMU17 Summary v DBMS used to maintain, query large datasets. v Benefits include recovery from system crashes, concurrent access, quick application development, data integrity and security. v Levels of abstraction give data independence. v We will learn how to –Set up a database u Design (ERD and Relational Model), and refine (Relational Normalization Theory) –Use to query the database u Relational Algebra and SQL