1. FEN 2015-08-311 Introduction to the database field:  Applications, concepts and terminology Seminar: Introduction to relational databases

2. Databases and Database Applications Textual and numerical databases Multimedia Databases GIS (Geographic Information Systems) Data Warehouse Real-time and active databases And many-many more FEN 2015-08-312

3. What is a Database? A database is a collection of related data. A database is a logical coherent collection of data with some inherent meaning. Hence a random collection of data is not a database. A database is designed, built and populated with data for a specific purpose for a specific group of users with requirements for specific applications. A database represents some aspect of the real word, sometimes called the miniworld or domain. FEN 2015-08-313

4. What is a DBMS? A DBMS (Database Management System) is a collection of programs that enables the users to create and maintain databases. This involves Defining a database (data types, structures and constraints) and handling meta data. Storing the data on some suitable storage medium and controlling the storage. Manipulating the database (executing queries and updating the database) Sharing the database allowing multiple users and application to access the database simultaneously. Providing interfaces to interactive users and/or application programs. FEN 2015-08-314 Sometimes called a Database Server or Database Engine Sometimes called a Database Server or Database Engine Do you know some DBMS? For instance: Oracle MySQL MS SQL Server PostgreSQL and many more For instance: Oracle MySQL MS SQL Server PostgreSQL and many more

5. What is a Database System? A database system is a database and a database management system put together: Database + DBMS == Database system FEN 2015-08-315

6. Overview Database DBMS Database System FEN 2015-08-316

7. Data Models Database systems are build upon a data model. A data model is a collection of concepts used to describe the structure of a database. A data model provides data abstraction, hides storage details and gives users (and developers) a conceptual view of the database. A data model should provide means to describe: Structure Data types Relationships Constraints Operations FEN 2015-08-317

8. Data Models Legacy (pre-relational) Hierarchical Network Record based Relational Post-relational Key-Value stores Object oriented Object-relational Temporal XML Cubes in Data Warehouse... FEN 2015-08-318 The relational model is still very central and the most used. Also known as NoSQL databases (NoSQL means Not Only SQL).

9. Relational Databases All data is organised in tables with atomic values Associations are represented by primary key/foreign key connections Every operation operates on tables and returns tables FEN 2015-08-319 Small exercise (5 min..): Describe step by step (which tables are used and how) how you will retrieve this information: When did Mr Smith attend the “Intro to Computer Science” course, who was the instructor and what grade did he receive?