1. Database Management Systems

2.  Instructor: Yrd. Doç. Dr. Cengiz Örencik  E-mail: cengizorencik@beykent.edu.trcengizorencik@beykent.edu.tr  Course material  http://myweb.sabanciuniv.edu/cengizo/cour ses http://myweb.sabanciuniv.edu/cengizo/cour ses ◦ all the notes will be shared there

3.  Not required  You may use any database book  Database Management Systems – 3 rd Edition ◦ Ramakrishnan and Gehrke

4.  Midterm 40%  Inclass quizzes (2)10%  Final50%  Hws ◦ Self study ◦ Not to be graded 4

5.  Managing data  Introduction to Database design ◦ Entities, attributes, relationships, etc. ◦ ER model  Relational Model ◦ Representing data ◦ Create, modify, query…  Relational Algebra vs. SQL  Storage and Indexing  Transaction Management ◦ Concurrency control ◦ Crash recovery 5

6. Database Management System (DBMS) provides…. … efficient, reliable, convenient, and safe multi-user storage of and access to massive amounts of persistent data.

7.  Massive – terrabytes/day  Persistent  Safe – hard/software failure, power cut  Multi-user  Convenient  Efficient  Reliable

8.  A Database Management System (DBMS) is a software package designed to store and manage databases  We will not consider:  Database applications may be programmed via “frameworks” ◦ Environments that help to develop program ◦ Ruby on rails, Django…  DBMS may run in conjunction with “middleware” ◦ Web servers that interact with database  Data-intensive applications may not use DBMS at all ◦ Store everything on files

9.  Data independence ◦ Application programs don’t need details of data representation and storage  Efficient access ◦ A variety of techniques  Data integrity and security ◦ Enforce constraints, access control…  Uniform data administration ◦ How different groups of users use it ◦ Organized to minimize redundancy  Reduced application development time ◦ DBMS support most common important functions  Concurrent access, recovery from crashes ◦ Multiple users use it without conflict ◦ Protect from effects of system failures

10.  Data described as a set of records  Example: Student information in a university  Students(sid: integer, name: string, mail: string, age: integer, gpa: real) SidNameMailAgeGpa 53666Jonejone@cs203.2 53680Smithsmith@cs212.9 53442Smithsmith@math193.85 53123Alicealice@ee213.5

11.  Relation  student  Each column  attributes  Each row is a record that describes a student  Integrity constraints ◦ Sid must be unique

12.  What is the name of the student with sid 53680?  How many students are enrolled to DBMS course?  What fraction of students of DBMS course get a grade better than BB?

13.  DBMS implementer ◦ Builds the system ◦ Works for IBM or Oracle  Database designer ◦ Interact users ◦ Establishes the schema - relations ◦ How to structure – how to store  Database application developer ◦ Builds the programs that operate on the database ◦ Use tools DBMS provides ◦ Usually not computer professionals  Database administrator ◦ loads the data, keep it running

14.  DBMS used to maintain, query large datasets  Benefits include recovery from system crashes, concurrent access, quick application development, data integrity and security  DBAs hold responsible jobs and are well paid  Whether you know it or not, you’re using a database every hour