Database Systems I Foundations of Databases Summer term 2010 Melanie Herschel [email protected] Database Systems Group, University of Tübingen 1 Chapter 0 Overview • Overview • Administrativa • A little bit of History 2 Foundations of Databases | Summer term 2010 Credit: Michael Marcol Melanie Herschel | University of Tübingen http://www.freedigitalphotos.net/images/view_photog.php?photogid=371 Welcome Everyone! First of all, let me introduce myself... Grew up in Bavaria & Lorraine Student at the University of Cooperative Education Stuttgart 2000 - 2003 Information Technology Research Assistant at Humboldt University in Berlin & at the Hasso-Plattner-Institute Potsdam 2003 - 2007 Data quality & data integration 2007 PhD defense Post-Doc researcher at the IBM Almaden Research Center 2008 - 2009 Data provenance / query understanding Research assistant at Tübingen University since 06/2009 “Debugging” queries with Nautilus Melanie B315, HerschelSand 13 Tel +49 7071 29-75481 [email protected] Email http://www-db.informatik.uni-tuebingen.de/team/herschel Web 3 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen Welcome Everyone! ... and now it is your turn. locals or “neigscheckte”? Which semester? Computer science, bioinformatics, other studies? Bachelor vs. Diplom? Prior experience with databases? 4 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen Where to Meet Databases 5 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen 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 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen 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 1. Introduction ‣ Relational model, ER -> relational, normal forms 2. ER-Modeling • Relational algebra 3. Relational model(ing) ‣ Criteria for query languages, operators 4. Relational algebra • SQL 5. SQL ‣ SQL DDL, SQL DML, SELECT... FROM... WHERE... 6. Programming • Programming for databases ‣ JDBC 7 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen What is this course about? ER-Modeling 1,1 1,n Customer owns Account Firstname Lastname DOB Number Type Balance • We want to model customers and their accounts 1. Introduction (saving account, checking account, credit card, ...) 2. ER-Modeling 3. Relational model(ing) • Customers and accounts have attributes, e.g., a 4. Relational algebra person has a firstname, lastname, and date of birth. 5. SQL 6. Programming • A customer can have one or more accounts. • We assume that an account can only have one owner. 9 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen What is this course about? Relational Model 1,1 1,n Customer owns Account Firstname Lastname DOB Number Type Balance 1. Introduction Customer 2. ER-Modeling Cust_ID Firstname Lastname DOB 3. Relational model(ing) 4. Relational algebra Account CREATE TABLE Account ( 5. SQL Number Type Balance Cust_ID Number INTEGER, 6. Programming Type CHAR(25), Balance DOUBLE, Cust_ID INTEGER, PRIMARY KEY (Number), FOREIGN KEY Cust_ID REFERENCES Customer ) 10 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen What is this course about? Relational Model Customer Cust_ID Firstname Lastname DOB 1 John Doe 1.1.1970 2 Jane Smith 2.2.1977 4 Peter Miller 3.3.1983 ... ... ... ... 1. Introduction 2. ER-Modeling Account 3. Relational model(ing) Number Type Balance Cust_ID 4. Relational algebra 123 Checking 2000 1 5. SQL 124 Saving 5000 1 6. Programming 987 Checking 100 2 975 Credit 500 2 777 Saving 6000 4 ... ... ... ... 11 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen 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. 1. Introduction Relational Algebra 2. ER-Modeling 3. Relational model(ing) πlastname,number (σbalance > 1000 ( 4. Relational algebra σ (customer × account)) c.cust_id = a.cust_id 5. SQL SQL 6. Programming SELECT c.lastname, a.number FROM Customer c, Account a WHERE a.balance > 1000 AND a.cust_id = c.cust_id 12 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen 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 1. Introduction 2. ER-Modeling ‣ Processing query results 3. Relational model(ing) ... 4. Relational algebra ResultSet r = 5. SQL statement.executeQuery(myQueryString); 6. Programming while (r.next()) { String lastname = r.getString(1); String accountNumber = r.getInt(2); Address a = getAddress(lastname, accountNumber); initCommercial(a); } 13 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen 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? Where? Monday, 10:15 - 11:45 Sand 6/7 kleiner Hörsaal Tuesday, 10:15 - 11:45 Sand 6/7 großer Hörsaal Practicals When? Where? Thursday, 14:15 - 15:45 Sand 13, A104 • First assignment available on April 15, 2010. • First assignment will be discussed April 22, 2010. 15 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen Administrativa Keep up to date http://www-db.informatik.uni-tuebingen.de/teaching/ss10/db1 Please visit regularly, as the latest slides and news will be posted there. http://twitter.com/DBatUTuebingen Stay tuned to the latest database group news. https://cis.informatik.uni-tuebingen.de/db1-ss-10/ Register in order to view assignments and access your scores. 16 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen 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 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen These slides... Quizzies Definition Examples Code snippets 18 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen 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 http://www-01.ibm.com/software/data/db2/express/ 19 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen Further!"#$"%"&'#$"%($)% literature !"#$%"& '"(")"*+ ,"$-. !" 20 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen *"+#,&-().(//&0&1'&2($"/3(/4565$"."&7&0&89.."%&:;;< Questions and Feedback • Questions anytime! • During the lecture • In dedicated office hour: Monday, 15:00 - 16:00 • Email, phone • Feedback and suggestions are highly appreciated • Slides • Information on the Website • ... 21 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen Before we get started... ... Commercials Studien- / Bachelor- / Diplom- / Masterarbeiten http://www-db.informatik.uni-tuebingen.de/teaching/studentische-arbeiten 22 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen Selected Fun Problems of the ACM Programming Contest Proseminar SS 2010 www-db.informatik.uni-tuebingen.de Vorbesprechung: 15.04.2010, 09:30, B305b 23 Foundations of Databases | Summer term 2010 | Melanie Herschel | University of Tübingen 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 - 1896 •Computing-Tabulating-Recording Company (C-T-R) - 1911 •International