Making Database Systems Usable

1. Making Database Systems Usable University of Michigan H.V. Jagadish, Adriane Chapman, Aaron Elkiss, Magesh Jayapandian, Yunyao Li, Arnab Nandi, Cong Yu Christiano Santiago

2. Agenda • Users Expectations • The Persistence of Pain • The Painless Future • Conclusion • Q&A Christiano Santiago

3. Users ExpectationsDatabase interactions • Ability to query in a more sophisticated way, using complex query semantics • More precise and complete answers • Expectation of structure in the result set • Create and update databases Christiano Santiago

4. The Persistence Of Pain Christiano Santiago

5. Higher Level Presentation Data ModelPainful Relations Christiano Santiago

6. Higher Level Presentation Data ModelPainful Relations Simple concept versusImplementation X Flight info Christiano Santiago

7. Higher Level Presentation Data ModelPainful Relations What are the fligth departure times from Detroit to Beijing? SELECT s.departure_time FROM schedule AS s, flight_info AS f, airports AS d, airports AS a WHERE s.id = f.schedule_id AND f.fid = d.id AND d.city_name = “Beijing” AND f.tid = a.id AND a.city_name = “Detroit” Christiano Santiago

8. Higher Level Presentation Data ModelPainful Relations Problems • Large number of table • Poorly named entities • Poorly named fields • Joins are not intuitive • Recursive self-joins • SQL is too onerous • Dependency on DBA (please don’t leave!) Christiano Santiago

9. Multiple Ways to Access DataPainful Options Christiano Santiago

10. Multiple Ways to Access DataPainful Options Too much functionality and too many options X Christiano Santiago

11. Multiple Ways to Access DataPainful Options Barry Schwartz, The tyranny of choice. Scientific American, April 2004, pp. 71-75 Christiano Santiago

12. Multiple Ways to Access DataPainful Options Perspectives • Design systems for customized value • Care about how well uses can get their job done • Forms-based interfaces have been the primary means to interact with databases • Provide simple querying tools for novice users and powerful tools for experts (customization) Christiano Santiago

13. Precision and RecallUnexpected Pain Christiano Santiago

14. Precision and RecallUnexpected Pain X Christiano Santiago

15. Precision and RecallUnexpected Pain Search engines error acceptance • Expectations are set correctly • Usually top few results do contain something relevant • If no relevant results were found, search it again • The web is so huge that no one knows exactly what is out there Christiano Santiago

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17. X Precision and RecallUnexpected Pain Unable to query • Systems may impede users from querying the way they want • Scenario: world traveler with infinite flexibility and many destinations to visit Christiano Santiago

18. Precision and RecallUnexpected Pain Unable to query • User’s versus form designer’s mental model of the data. • Users should be worried about how. They just need the what. • Challenge #1: it’s not easy to provide a straightforward and comprehensive way of specifying what a user wants when a query requires aggregation or multiple complex joins. • Challenge #2: performance, security access level, data or program errors may prevent users from running a query. Christiano Santiago

19. Precision and RecallUnexpected Pain Unexpected results • (Unexpected results) + (no explanation) = frustration • Example 1 • The client record shows he has 2 cars • but • There is only 1 car related to this client in the database. # of cars was a field in the Clienttable, with no referential Integrity with CarOwnertable Christiano Santiago

20. Precision and RecallUnexpected Pain Unexpected results • (Unexpected results) + (no explanation) = frustration • Example 2 • User is looking for cheap flights provided by her favorite airline: • Los Angeles for $75 • Boston for $100 • San Francisco for $400 (?) $400 was less than half the average price for a ticket to San Francisco Christiano Santiago

21. Precision and RecallUnexpected Pain Unexpected results • Empty & non-empty results • Users may need to know where a result comes from • Users may need to know why a result is returned • System’s usability can be significantly affected when no explanation can be given Christiano Santiago

22. Errors In Query ConstructionUnseen Pain Christiano Santiago

23. Errors In Query ConstructionUnseen Pain Database Users versus Computer Scientists X Christiano Santiago

24. Errors In Query ConstructionUnseen Pain Christiano Santiago

25. Errors In Query ConstructionUnseen Pain Perspectives • Query purpose: provide information that the user doesn’t have • How do I provide a clear and precise “from” and “where” clause, if I don’t know the possibilities? • WYSIWYG Christiano Santiago

26. Errors In Query ConstructionUnseen Pain WYISWYG Assisted Querying using Instant-Response Interfaces Arnab Nandi & H. V. Jagadish - University of Michigan Christiano Santiago

27. Errors In Query ConstructionUnseen Pain WYISWYG • Google Earth approach • Can you image finding a location in a map using coordinates instead of zoom and rotation? Christiano Santiago

28. Database CreationBirthing pain Christiano Santiago

29. Database CreationBirthing pain Corporate Market versus Average User X Christiano Santiago

30. Database CreationBirthing pain Perspectives • Users want to store their data into databases but this is not an easy task • Database schema • Table structure • Normalization • Relationships • Constraints Christiano Santiago

31. Database CreationBirthing pain Perspectives • An everyday database • No clear view of required database structure • No comprehensive design at starting point • Structure grows as time passes • Structure grows incrementally • Need to support both structured and unstructured information Christiano Santiago

32. The Painless Future Christiano Santiago

33. The Painless FutureGeographic Model • Joins between data sets using geographic or spatial location as the basis Christiano Santiago

34. The Painless FutureNetwork Model • Graph or network representation of data. Christiano Santiago

35. The Painless FutureMultidimensional Model • Data as points in multi-dimensional space Christiano Santiago

36. The Painless FutureTabular Model • People is used to seeing data represented in simple two-dimensional tables Christiano Santiago

37. The Painless FuturePresentation Data Models Perspectives • Data manipulation through presentation data model versus view updates • Consistency among view options: geographic and textual views in synchrony • Data provenance: “why” and “where” related to result sets • Direct data manipulation • Point-and-click, drag-and-drop, etc. • New few number of algebra operators to support it • Schema-later (unstructured) and heterogeneous database design Christiano Santiago

38. Conclusion • Databases are extremely difficult for most people to interact with. • We must rethink the architecture of the database systems as a whole. • Presentation model as a distinct layer above usual logical data model. Christiano Santiago

39. Questions & Answers Christiano Santiago