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Temporal Database

Temporal Database

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Temporal Database

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  1. Temporal Database Chap 4: Temporal Extensions to the Relational Model and SQL

  2. 4.2 Temporal Relational Model (TRM)

  3. 4.2 Temporal Relational Model (TRM)

  4. 4.2.1 Synchronism and Temporal Dependence Here, an Employee gets a raise in salary if and only if he or she gets a promotion, and an employee is never demoted. Thus, the TVA’s Salary and Position form a set of synchronous attributes .

  5. 4.2.1 Synchronism and Temporal Dependence Plane# is the identifier of an aircraft, Part is the name of a part, Cond describes the nature of the problem the part has, Place is the name of the place where it is being serviced, Cost is the cost associated with the Ts is the time when a particular maintenance event began , and TE is the time when it terminated.

  6. 4.2.1 Synchronism and Temporal Dependence

  7. 4.2.2 Time Normalization Sal-Mgr (Table 4.3) can be decomposed into two relations, Manager (Table 4.4) and Salary (Table 4.5)

  8. 4.2.2 Time Normalization

  9. 4.3 TSQL: A Language Interface for TRM

  10. 4.3 TSQL: A Language Interface for TRM

  11. 4.3 TSQL: A Language Interface for TRM

  12. 4.3.1 The WHEN Clause

  13. 4.3.1 The WHEN Clause

  14. 4.3.2 Retrieval of Timestamps

  15. 4.3.3 Temporal Ordering If there are n breaks for a given TIK value, then the tuples can be viewed as having been partitioned into n+1 groups. If breaks are taken into consideration for temporal ordering, the tuples in each of these groups created by the presence of breaks – are given a unique set of ordinal numbers.

  16. 4.3.3 Temporal Ordering

  17. 4.3.3 Temporal Ordering

  18. 4.3.4 The TIME-SLICE Clause

  19. 4.3.5 Aggregate Functions and GROUP BY

  20. 4.3.5 Aggregate Functions and GROUP BY

  21. 4.3.6 The Moving Window

  22. 4.3.6 The Moving Window

  23. 4.4 Temporal Relational Operators

  24. 4.4.2 COMPRESS