1. 2004.11.29- SLIDE 1IS 257 – Fall 2004 Future of Database Systems University of California, Berkeley School of Information Management and Systems SIMS 257: Database Management

2. 2004.11.29- SLIDE 2IS 257 – Fall 2004 Lecture Outline Review –Object-Oriented Database Development Future of Database Systems Predicting the future… Quotes from Leon Kappelman “The future is ours” CACM, March 2001 Accomplishments of database research over the past 30 years Next-Generation Databases and the Future

3. 2004.11.29- SLIDE 3IS 257 – Fall 2004 Lecture Outline Review –Object-Oriented Database Development Future of Database Systems Predicting the future… Quotes from Leon Kappelman “The future is ours” CACM, March 2001 Accomplishments of database research over the past 30 years Next-Generation Databases and the Future

4. 2004.11.29- SLIDE 4IS 257 – Fall 2004 Object Definition Language (ODL) Corresponds to SQL’s DDL (Data Definition Language) Specify the logical schema for an object-oriented database Based on the specifications of Object Database Management Group (ODMG)

5. 2004.11.29- SLIDE 5IS 257 – Fall 2004 Defining a Class class – keyword for defining classes attribute – keyword for attributes operations – return type, name, parameters in parentheses relationship – keyword for establishing relationship

6. 2004.11.29- SLIDE 6IS 257 – Fall 2004 Defining an Attribute Value can be either: –Object identifier OR Literal Types of literals –Atomic – a constant that cannot be decomposed into components –Collection – multiple literals or object types –Structure – a fixed number of named elements, each of which could be a literal or object type Attribute ranges –Allowable values for an attribute –enum – for enumerating the allowable values

7. 2004.11.29- SLIDE 7IS 257 – Fall 2004 Kinds of Collections Set – unordered collection without duplicates Bag – unordered collection that may contain duplicates List – ordered collection, all the same type Array – dynamically sized ordered collection, locatable by position Dictionary – unordered sequence of key- value pairs without duplicates

8. 2004.11.29- SLIDE 8IS 257 – Fall 2004 Defining Structures Structure = user-defined type with components struct struct keyword Example: struct Address { String street_address String city; String state; String zip; };

9. 2004.11.29- SLIDE 9IS 257 – Fall 2004 Defining Operations Return type Name Parentheses following the name Arguments within the parentheses

10. 2004.11.29- SLIDE 10IS 257 – Fall 2004 Defining Relationships Only unary and binary relationships allowed Relationships are bi-directional –implemented through use of inverse keyword ODL relationships are specified: –relationship indicates that class is on many-side –relationship set indicates that class is on one-side and other class (many) instances unordered –relationship list indicates that class is on one-side and other class (many) instances ordered

11. 2004.11.29- SLIDE 11IS 257 – Fall 2004 Figure 15-1 –UML class diagram for a university database The following slides illustrate the ODL implementation of this UML diagram

12. 2004.11.29- SLIDE 12IS 257 – Fall 2004 Figure 15-2 –ODL Schema for university database

13. 2004.11.29- SLIDE 13IS 257 – Fall 2004 Querying Objects in the OODB Object Query Language (OQL) ODMG standard language Similar to SQL-92 Some differences: –Joins use class’s relationship name: Select x.enrollment from courseofferings x, x.belongs_to y where y.crse_course = “MBA 664” and x.section = 1; –Using a set in a query Select emp_id, name from employees where “Database Design” in skills;

14. 2004.11.29- SLIDE 14IS 257 – Fall 2004 Current ODBMS Products Rising popularity due to: –CAD/CAM applications –Geographic information systems –Multimedia –Web-based applications –Increasingly complex data types Applications of ODBMS –Bill-of-material –Telecommunications navigation –Health care –Engineering design –Finance and trading

15. 2004.11.29- SLIDE 15IS 257 – Fall 2004 Lecture Outline Review –Object-Oriented Database Development Future of Database Systems Predicting the future… Quotes from Leon Kappelman “The future is ours” CACM, March 2001 Accomplishments of database research over the past 30 years Next-Generation Databases and the Future

16. 2004.11.29- SLIDE 16IS 257 – Fall 2004 Radio has no future, Heavier-than-air flying machines are impossible. X-rays will prove to be a hoax. –William Thompson (Lord Kelvin), 1899

17. 2004.11.29- SLIDE 17IS 257 – Fall 2004 This “Telephone” has too many shortcomings to be seriously considered as a means of communication. The device is inherently of no value to us. –Western Union, Internal Memo, 1876

18. 2004.11.29- SLIDE 18IS 257 – Fall 2004 I think there is a world market for maybe five computers –Thomas Watson, Chair of IBM, 1943

19. 2004.11.29- SLIDE 19IS 257 – Fall 2004 The problem with television is that the people must sit and keep their eyes glued on the screen; the average American family hasn’t time for it. –New York Times, 1949

20. 2004.11.29- SLIDE 20IS 257 – Fall 2004 Where … the ENIAC is equipped with 18,000 vacuum tubes and weighs 30 tons, computers in the future may have only 1000 vacuum tubes and weigh only 1.5 tons –Popular Mechanics, 1949

21. 2004.11.29- SLIDE 21IS 257 – Fall 2004 There is no reason anyone would want a computer in their home. –Ken Olson, president and chair of Digital Equipment Corp., 1977.

22. 2004.11.29- SLIDE 22IS 257 – Fall 2004 640K ought to be enough for anybody. –Attributed to Bill Gates, 1981

23. 2004.11.29- SLIDE 23IS 257 – Fall 2004 By the turn of this century, we will live in a paperless society. –Roger Smith, Chair of GM, 1986

24. 2004.11.29- SLIDE 24IS 257 – Fall 2004 I predict the internet… will go spectacularly supernova and in 1996 catastrophically collapse. –Bob Metcalfe (3-Com founder and inventor of ethernet), 1995

25. 2004.11.29- SLIDE 25IS 257 – Fall 2004 Lecture Outline Review –Object-Oriented Database Development Future of Database Systems Predicting the future… Quotes from Leon Kappelman “The future is ours” CACM, March 2001 Accomplishments of database research over the past 30 years Next-Generation Databases and the Future

26. 2004.11.29- SLIDE 26IS 257 – Fall 2004 Database Research Database research community less than 40 years old Has been concerned with business type applications that have the following demands: –Efficiency in access and modification of very large amounts of data –Resilience in surviving hardware and software errors without losing data –Access control to support simultaneous access by multiple users and ensure consistency –Persistence of the data over long time periods regardless of the programs that access the data Research has centered on methods for designing systems with efficiency, resilience, access control, and persistence and on the languages and conceptual tools to help users to access, manipulate and design databases.

27. 2004.11.29- SLIDE 27IS 257 – Fall 2004 Accomplishments of DBMS Research DBMS are now used in almost every computing environment to create, organize and maintain large collections of information, and this is largely due to the results of the DBMS research community’s efforts, in particular: –Relational DBMS –Transaction management –Distributed DBMS

28. 2004.11.29- SLIDE 28IS 257 – Fall 2004 Relational DBMS The relational data model proposed by E.F. Codd in papers (1970-1972) was a breakthrough for simplicity in the conceptual model of DBMS. However, it took much research to actually turn RDBMS into realities.

29. 2004.11.29- SLIDE 29IS 257 – Fall 2004 Relational DBMS During the 1970’s database researchers: –Invented high-level relational query languages to ease the use of the DBMS for end users and applications programmers. –Developed Theory and algorithms needed to optimize queries into execution plans as efficient and sophisticated as a programmer might have custom designed for an earlier DBMS

30. 2004.11.29- SLIDE 30IS 257 – Fall 2004 Relational DBMS –Developed Normalization theory to help with database design by eliminating redundancy –Developed clustering algorithms to improve retrieval efficiency. –Developed buffer management algorithms to exploit knowledge of access patterns –Constructed indexing methods for fast access to single records or sets of records by values –Implemented prototype RDBMS that formed the core of many current commercial RDBMS

31. 2004.11.29- SLIDE 31IS 257 – Fall 2004 Relational DBMS The result of this DBMS research was the development of commercial RDBMS in the 1980’s When Codd first proposed RDBMS it was considered theoretically elegant, but it was assumed only toy RDBMS could ever be implemented due to the problems and complexities involved. Research changed that.

32. 2004.11.29- SLIDE 32IS 257 – Fall 2004 Transaction Management Research on transaction management has dealt with the basic problems of maintaining consistency in multi-user high transaction database systems

33. 2004.11.29- SLIDE 33IS 257 – Fall 2004 No Transactions : Lost updates Read account balance (balance = $1000) Transfer $100 to Mel Debits $100 SYSTEM CRASH Read account balance (balance = $900) Read account balance (balance = $1000) SYSTEM CRASH Read account balance (balance = $1000) John Mel ERROR!

34. 2004.11.29- SLIDE 34IS 257 – Fall 2004 No Concurrency Control: Lost updates Read account balance (balance = $1000) Withdraw $200 (balance = $800) Write account balance (balance = $800) Read account balance (balance = $1000) Withdraw $300 (balance = $700) Write account balance (balance = $700) John Marsha ERROR!

35. 2004.11.29- SLIDE 35IS 257 – Fall 2004 Transaction Management To guarantee that a transaction transforms the database from one consistent state to another requires: –The concurrent execution of transactions must be such that they appear to execute in isolation. –System failures must not result in inconsistent database states. Recovery is the technique used to provide this.

36. 2004.11.29- SLIDE 36IS 257 – Fall 2004 Distributed Databases The ability to have a single “logical database” reside in two or more locations on different computers, yet to keep querying, updates and transactions all working as if it were a single database on a single machine How do you manage such a system?

37. 2004.11.29- SLIDE 37IS 257 – Fall 2004 Lecture Outline Review –Object-Oriented Database Development Future of Database Systems Predicting the future… Quotes from Leon Kappelman “The future is ours” CACM, March 2001 Accomplishments of database research over the past 30 years “Next-Generation Databases” and the Future

38. 2004.11.29- SLIDE 38IS 257 – Fall 2004 Next Generation Database Systems Where are we going from here? –Hardware is getting faster and cheaper –DBMS technology continues to improve and change OODBMS ORDBMS –Bigger challenges for DBMS technology Medicine, design, manufacturing, digital libraries, sciences, environment, planning, etc...

39. 2004.11.29- SLIDE 39IS 257 – Fall 2004 Examples NASA EOSDIS –Estimated 10 16 Bytes (Exabyte) Computer-Aided design The Human Genome Department Store tracking –Mining non-transactional data (e.g. Scientific data, text data?) Insurance Company –Multimedia DBMS support

40. 2004.11.29- SLIDE 40IS 257 – Fall 2004 New Features New Data types Rule Processing New concepts and data models Problems of Scale Parallelism/Grid-based DB Tertiary Storage vs Very Large-Scale Disk Storage Heterogeneous Databases Memory Only DBMS

41. 2004.11.29- SLIDE 41IS 257 – Fall 2004 Coming to a Database Near You… Browsibility User-defined access methods Security Steering Long processes Federated Databases IR capabilities XML The Semantic Web(?)

42. 2004.11.29- SLIDE 42IS 257 – Fall 2004 Some things to consider Bandwidth will keep increasing and getting cheaper (and go wireless) Processing power will keep increasing –Moore’s law: Number of circuits on the most advanced semiconductors doubling every 18 months Memory and Storage will keep getting cheaper (and probably smaller) –“Storage law”: Worldwide digital data storage capacity has doubled every 9 months for the past decade Put it all together and what do you have? –“The ideal database machine would have a single infinitely fast processor with infinite memory with infinite bandwidth – and it would be infinitely cheap (free)” : David DeWitt and Jim Gray, 1992