Database Systems I. Chapter 0 Overview. Foundations of Databases Summer term Melanie Herschel

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1 Database Systems I Foundations of Databases Summer term 2010 Melanie Herschel melanie.herschel@uni-tuebingen.de Database Systems Group, University of Tübingen 1 Chapter 0 Overview Overview Administrativa A little bit of History 2 Foundations of Databases Summer term 2010 Melanie Herschel University of Tübingen Credit: Michael Marcol

2 Which semester? Welcome Everyone! First of all, let me introduce myself PhD defense since 06/2009 Grew up in Bavaria & Lorraine Student at the University of Cooperative Education Stuttgart Information Technology Research Assistant at Humboldt University in Berlin & at the Hasso-Plattner-Institute Potsdam Data quality & data integration Post-Doc researcher at the IBM Almaden Research Center Data provenance / query understanding Research assistant at Tübingen University Debugging queries with Nautilus Melanie Herschel B315, Sand 13 Tel melanie.herschel@uni-tuebingen.de Web 3 Welcome Everyone!... and now it is your turn. locals or neigscheckte? Computer science, bioinformatics, other studies? Bachelor vs. Diplom? Prior experience with databases? 4

3 Where to Meet Databases 5 What is this course about? Convince you that there is more to database technology than just open-file(), read()/write(), and close-file(). Make you see how versatile the strictly tabular data model supported by relational databases can be. Make you best friends with SQL, the principal language spoken by relational database systems. We will encounter a healthy mix of good, clean theory and highly relevant CS practice. 6

4 What is this course about? Structure What are databases? Motivation, history, data independence, database usage Modeling databases using the Entity-Relationship Model Entities, relationships, cardinalities, diagrams Developing relational databases Relational model, ER -> relational, normal forms Relational algebra Criteria for query languages, operators SQL SQL DDL, SQL DML, SELECT... FROM... WHERE... Programming for databases JDBC 1. Introduction 2. ER-Modeling 3. Relational model(ing) 4. Relational algebra 5. SQL 6. Programming 7 What is this course about? ER-Modeling Customer 1,1 1,n owns Account Firstname Lastname DOB Number Type Balance We want to model customers and their accounts (saving account, checking account, credit card,...) Customers and accounts have attributes, e.g., a person has a firstname, lastname, and date of birth. A customer can have one or more accounts. 1. Introduction 2. ER-Modeling 3. Relational model(ing) 4. Relational algebra 5. SQL 6. Programming We assume that an account can only have one owner. 9

5 What is this course about? Relational Model Customer 1,1 1,n owns Account Firstname Lastname DOB Number Type Balance Customer Cust_ID Firstname Lastname DOB Account Number Type Balance Cust_ID CREATE TABLE Account ( Number INTEGER, Type CHAR(25), Balance DOUBLE, Cust_ID INTEGER, PRIMARY KEY (Number), FOREIGN KEY Cust_ID REFERENCES Customer ) 1. Introduction 2. ER-Modeling 3. Relational model(ing) 4. Relational algebra 5. SQL 6. Programming 10 What is this course about? Relational Model Customer Cust_ID Firstname Lastname DOB 1 John Doe Jane Smith Peter Miller Account Number Type Balance Cust_ID 123 Checking Saving Checking Credit Saving Introduction 2. ER-Modeling 3. Relational model(ing) 4. Relational algebra 5. SQL 6. Programming 11

6 What is this course about? Relational Algebra & SQL Declarative queries Not How do I generate the query result? But What data does the query result contain? Natural language query Name of account owner and account number of all accounts with a balance of more than 1000 Euros. Relational Algebra πlastname,number (σbalance > 1000 ( σc.cust_id = a.cust_id (customer account)) SQL SELECT c.lastname, a.number FROM Customer c, Account a WHERE a.balance > 1000 AND a.cust_id = c.cust_id 1. Introduction 2. ER-Modeling 3. Relational model(ing) 4. Relational algebra 5. SQL 6. Programming 12 What is this course about? Programming (if time permits) Accessing the database from an external program For instance, from a JAVA program, we can communicate with a database via JDBC. JDBC Driver Open Connection Querying the database Processing query results... ResultSet r = statement.executequery(myquerystring); while (r.next()) { String lastname = r.getstring(1); String accountnumber = r.getint(2); Address a = getaddress(lastname, accountnumber); initcommercial(a); 1. Introduction 2. ER-Modeling 3. Relational model(ing) 4. Relational algebra 5. SQL 6. Programming } 13

7 Chapter 0 Overview Overview Administrativa A little bit of History 14 Foundations of Databases Summer term 2010 Melanie Herschel University of Tübingen Administrativa Course schedule Lectures When? Monday, 10:15-11:45 Tuesday, 10:15-11:45 Where? Sand 6/7 kleiner Hörsaal Sand 6/7 großer Hörsaal Practicals When? Where? Thursday, 14:15-15:45 Sand 13, A104 First assignment available on April 15, First assignment will be discussed April 22,

8 Administrativa Keep up to date Please visit regularly, as the latest slides and news will be posted there. Stay tuned to the latest database group news. Register in order to view assignments and access your scores. 16 Administrativa Evaluating your Performance End-term exam 90 mins. examination on Monday, July 12th, from 10:15-11:45. No supplemental material is allowed. Passing earns you 6 ECTS. Assignments and grading We will distribute, collect, and grade weekly assignments. Assignments will be available on our website or via CIS. You have one week to complete each assignment. You may - and you should - work in teams of two. You should hand in your assignments in paper form at Manuel Mayr s office. Scoring 2/3 of the overall points in the assignments earns you an additional 2 ECTS. Your scores will be available via CIS only. 17

9 These slides... Quizzies Definition Examples Code snippets 18 Read a book, write some SQL Any introductory book is fine, two suggestions are Raghu Ramakrishnan and Johannes Gehrke. Database Management Systems. McGraw-Hill. (Vorlesung ist stark an diesem Buch orientiert) Alfons Kemper and André Eickler. Datenbanksysteme: Eine Einführung. Oldenbourg Verlag Install IBM DB2 V9.5 Express-C We will bring it with us for almost any lecture. Dowload at 19

10 Further!"#$"%"&'#$"%($)% literature!"#$%"& '"(")"*+,"$-. 20 Questions and Feedback Questions anytime! During the lecture In dedicated office hour: Monday, 15:00-16:00 , phone Feedback and suggestions are highly appreciated Slides Information on the Website... 21

11 Before we get started Commercials Studien- / Bachelor- / Diplom- / Masterarbeiten 22 Selected Fun Problems of the ACM Programming Contest Proseminar SS 2010 www-db.informatik.uni-tuebingen.de Vorbesprechung: , 09:30, B305b 23

12 Chapter 0 Overview Overview Administrativa A little bit of History 24 Foundations of Databases Summer term 2010 Melanie Herschel University of Tübingen A little bit of History Data Collection and Storage Technology Herman Hollerith: punch card tabulating machine Companies (precursors of IBM) Tabulating Machine Corp Computing-Tabulating-Recording Company (C-T-R) International Business Machines Corporation (IBM) Credit: IBM Archive, Computer History Museum, Mountain View, CA Computer History Museum, Mountain View, CA 25

13 A little bit of History Hard-Drive Technology Magnetic Disc Drive: RAMAC 350 by IBM /56 Random Access Method of Accounting and Control Developed in San Jose, CA Technical lead: Reynold B. Johnson ( ) Since then, HDD development has followed Moore s Law Cost per MB has decreased by half approx. every 18 months. The areal density (bits/inch 2 ) has doubled approx. every 18 months. Credit: IBM Archive, Computer History Museum, Mountain View, CA 26 A little bit of History Timeline Database systems based on the relational model Specialization to new types of data Object-oriented databases Database systems based on hierarchical model, network model Scaling database systems to the very large and the very small

14 A little bit of History Database Systems in The Sixties Early 1960s Data is stored in files. Application dependent organization of the data Integrated Data Store (IDS) by General Electric Late 1960s File management systems (SAM, ISAM) Basic operations on the data are possible, e.g., sorting Information Management System (IMS) by IBM Still in use on mainframes today, with more than 1 Billion $ revenue. 28 A little bit of History Relational Database Management Systems 1970s Database systems emerge Ted Codd (IBM): relational data model as conceptual basis for relational database systems System R (IBM): first prototype of a relational database management system Roughly 80,000 lines of code (PL/1, PL/S, Assembler) SEQUEL as a query language First installation in Ingres (University of Berkeley) QUEL as a query language Precursor of Postgres, Sybase,... Oracel Version

15 A little bit of History Relational Database Management Systems Credit: Prof. Freytag, Ringvorlesung A little bit of History Database Development in the 1980s and 1990s Systems become smaller and smaller. DBMS run on smaller hardware. DBMS become part of standard installations. Systems process more and more data. Gigabyte, Terabyte Large and complex (Multimedia-) objects Persistent storage using hard drives and tertiary storage (tapes, DVDs) Distributed and parallel processing Object-oriented database systems 31

16 A little bit of History Database Development in the new Millennium Support for new types of data XML- and semi-structured data Multimedia (Pictures, Audio, Video) Federated databases: integrating data from heterogeneous sources (databases, files, web-sources) Mobile databases Managing data on handheld devices (PDA, mobile phone,...) Data Warehouses: From transaction processing to analytical processing Information retrieval Distributed processing... 32