1. Lecture 16: Probabilistic Databases
Slides by Gerome Miklau
Based on a tutorial by Dan Suciu

2. Today’s Agenda Motivation Probabilistic Data Semantics
Representation Systems
Complexity

3. Section 1
1. Motivation

4. Motivating Applications
Section 1
Motivating Applications
Text extraction & record linkage
Inconsistent data
Ranking query answers

5. Section 1
Text extraction

6. Section 1
Record Linkage

7. Section 1
Inconsistent Data
Goal: consistent query answers from inconsistent databases
Applications:
Integration of autonomous data sources
Un-enforced integrity constraints
Temporary inconsistencies

8. Section 1
Repair semantics

9. Alternative probabilistic approach
Section 1
Alternative probabilistic approach

10. Ranking query answers Database is deterministic
Section 1
Ranking query answers
Database is deterministic
Query answers are uncertain:
Query terms loosened due to user’s lack of understanding of the data or schema
The query returns a ranked list of tuples; user interested in top-k

11. Summary: motivating applications
Section 1
Summary: motivating applications

12. 2. Probabilistic Data Semantics
Section 2
2. Probabilistic Data Semantics

13. Possible worlds semantics
Section 2
Possible worlds semantics

14. Section 2
The definition

15. Section 2
Example

16. Section 2
Tuples as Events

17. Section 2
Tuple correlation

18. Section 2
Example

19. Section 2
Query semantics

20. Section 2
Query semantics

21. Example: Query Semantics
Section 2
Example: Query Semantics

22. Section 2
Query semantics

23. 3. Representation Systems
Section 3
3. Representation Systems

24. Representation systems
Section 3
Representation systems

25. Representation systems
Section 3
Representation systems

26. Tuple independent probabilistic database
Section 3
Tuple independent probabilistic database

27. Tuple Prob. -> Possible Worlds
Section 3
Tuple Prob. -> Possible Worlds

28. Tuple Prob. -> Query evaluation
Section 3
Tuple Prob. -> Query evaluation

29. Tuple-independent distributions
Section 3
Tuple-independent distributions

30. Section 3
Intensional database

31. Intensional DB => Possible Worlds
Section 3
Intensional DB => Possible Worlds

32. Possible Worlds => Intensional DB
Section 3
Possible Worlds => Intensional DB

33. Closure under operators
Section 3
Closure under operators

34. Summary of Intensional Databases
Section 3
Summary of Intensional Databases

35. Section 4
4. Complexity

36. Probability of boolean expressions
Section 4
Probability of boolean expressions

37. Section 4
Example

38. Complexity of Boolean Expression Probability
Section 4
Complexity of Boolean Expression Probability

39. Section 4
Query complexity

40. Intensional query evaluation
Section 4
Intensional query evaluation

41. Extensional query evaluation
Section 4
Extensional query evaluation

42. Section 4

43. Section 4
Query complexity

44. Summary on query complexity
Section 4
Summary on query complexity