1. Chap1 Temporal Database Chap 1: The Historial Relational Data Model (HRDM) Revisited

2. Chap1 1.2 Lifespans

3. Chap1 1.2 Lifespans Associate a lifespan at the database level. A collection of relations that are homogeneous in the temporal dimension Associate a lifespan at the relation level. Each relation can be defined over different periods of time. All the tuples in a given relation are homogeneous.

4. Chap1 1.2 Lifespans Associate a lifespan at the tuple level. Each tuple can be defined over different periods of time. All the attributes in a given tuple are homogeneous.

5. Chap1 1.2 Lifespans

6. Chap1 1.2 Lifespans

7. Chap1 1.2 Lifespans

8. Chap1 1.3 Historical Relations in HRDM  Set of times, T={…, t 0, t 1,…} at most countably indefinite  Lifespan L: Any subset of the set T  Value domain D={D 1, D 2,… D nd }  TD={TD 1, TD 2,… TD nd } TD i ={f i | f i : T → D i }, a partial function from T into the value domain D i TT={g | g : T → T}  Set of attributes, U ={A 1, A 2,… A nd }  Historical Domain HD HD =(TD ∪ {TT})= ={TT, TD 1, TD 2,… TD nd }  Constant Domain CD

9. Chap1 1.3 Historical Relations in HRDM A relation scheme R=

10. Chap1 1.3 Historical Relations in HRDM

11. Chap1 1.3 Historical Relations in HRDM

12. Chap1 1.3 Historical Relations in HRDM

13. Chap1 1.3 Historical Relations in HRDM

14. Chap1 1.3 Historical Relations in HRDM

15. Chap1 1.4 The Historical Relational Algebra of HRDM

16. Chap1 1.4 The Historical Relational Algebra of HRDM

17. Chap1 1.4 The Historical Relational Algebra of HRDM

18. Chap1 1.4 The Historical Relational Algebra of HRDM

19. Chap1 1.4 The Historical Relational Algebra of HRDM

20. Chap1 1.4 The Historical Relational Algebra of HRDM

21. Chap1 1.4 The Historical Relational Algebra of HRDM Example??

22. Chap1 1.4 The Historical Relational Algebra of HRDM

23. Chap1 1.4 The Historical Relational Algebra of HRDM

24. Chap1 1.4 The Historical Relational Algebra of HRDM θ-Join Equijoin

25. Chap1 1.4 The Historical Relational Algebra of HRDM Natural-Join Time-Join