Small introduction about how to manage varying data.

1. Temporal Database
Linh Chau
Software Engineer
November 8th, 2017

2. 22
Agenda
▪ Introduction
▪ Bi-temporality
▪ Example
▪ Q&A

3. 33
What is temporal database?

4. 44
Traditional way
ID Name Price (x1000 VND)
1 Coconut Oil 650
2 Honey 220
3 Medical Oil 120

5. 55
Traditional way
▪ Store only current state of data.
▪ Modify data will overlap the existing data.

6. 66
Questions
▪ How to retrieve history data?
▪ What happen if you delete data by accident?
▪ What if I need to retrieve the data in the past, or insert a reserved data for
future use?
→ We need something like time period to attach to the data, this is temporal
data.
A temporal database is a database with built-in support for handling data
involving time.

7. 77
Temporal database
▪ Time period is attached to the data (time varying data).
▪ Express when the data is valid or stored in the database.
▪ Divided into two approaches:
▪ Time period when the data is true in the real world (valid time).
▪ Time period when data is stored in database (transaction time).

8. 88
Valid time approach
ID Name Price (x1000 VND)
1 Coconut Oil 650
2 Honey 220
3 Medical Oil 120

9. 99
Valid time approach
ID Name Price Valid From Valid Till
2 Honey 250 01/01/2016 01/09/2017
2 Honey 220 01/09/2017 02/02/2020
2 Honey 300 03/03/2025 04/04/2050
2 Honey 500 06/09/3000 09/06/3005

10. 1010
Valid time approach
▪ Records the time when a fact is true in the real world.
▪ Represents data in the past, current for future
▪ Enables queries that show the state of the fact at a given time.

11. 1111
Transaction time approach
ID Name Price
Valid
From
Valid Till
Known
From
Known
Till
2 Honey 250 01/01/2016 01/09/2017 08/08/2017 31/12/9999
2 Honey 220 01/09/2017 02/02/2020 08/08/2017 31/12/9999
2 Honey 300 03/03/2025 04/04/2050 08/08/2017 31/12/9999
2 Honey 500 06/09/3000 09/06/3005 08/08/2017 08/11/2017
2 Honey 5000 06/09/3000 09/06/3005 08/11/2017 31/12/9999

12. 1212
Transaction time approach
▪ Records the time period during which a database entry is accepted as
correct.
▪ Enables queries that show the state of the database at a given time.
▪ Only occur in the past or up to the current time.
▪ In a transaction time table, records are never deleted.

13. 1313
Bi-temporality

14. 1414
Bi-Temporality
07.01 13.02 27.05 25.07
10.01
15.02
07.06
19.06
Validity
Knowing
China
Switzerland
Japan
Vietnam

15. 1515
Bi-Temporality
07.01 13.02 27.05 25.07
10.01
15.02
07.06
19.06
Validity
Knowing
China
Switzerland
Japan
Vietnam

16. 1616
Bi-Temporality
▪ In bi-temporality, we take care both point of view the validity and point of
view of the change.
▪ Through them, we get the exact valid information of the system at specific
time.
▪ No physical delete of the row in database.

17. 1717
Use cases
▪ You want to reprint of a customer’s invoices of July 2017.
▪ What was the profit last year?
▪ Where do you enter the new address of this customer since the first next
month?
▪ The client wants to book a reservation of your hotel next year.

18. 1818
Application domains
▪ Financial apps: portfolio management, accounting, banking.
▪ Record-keeping: personal, medical, inventory management.
▪ Scheduling apps: airline, train, hotel reservation...
▪ CRM apps (customer history / future)
⇒ Time varying data has always been in business requirements.

19. 1919
Example

20. 2020
Insert
Insert record “A”, valid from 01.01.2016.

21. 2121
Insert
Valid
Know

22. 2222
Insert
sysdate
Valid
Know
01.01.2016

23. 2323
Insert
sysdate
Valid
Know
01.01.2016
A

24. 2424
Insert
Action Data Valid From Valid Till Known From Known Till
Insert A 01.01.2016 31.12.9999 sysdate 31.12.9999
▪ 01.01.2016: when the data is valid
▪ 31.12.9999: infinity
▪ sysdate: “now”

25. 2525
Delete
“Remove” record “A”

26. 2626
Delete
sysdate1
Valid
Know
01.01.2016
A

27. 2727
Delete
sysdate1
Valid
Know
01.01.2016
A
sysdate2

28. 2828
Delete
Action Data Valid From Valid Till Known From Known Till
Update A - - - sysdate
▪ “-”: no change

29. 2929
Close
Update record “A”, set valid until 06.06.2016.

30. 3030
Close
sysdate1
Valid
Know
01.01.2016
A

31. 3131
Close
sysdate1
Valid
Know
01.01.2016
A
A
sysdate2
06.06.2016

32. 3232
Close
Action Data Valid From Valid Till Known From Known Till
Update A - - - sysdate
Insert A 01.01.2016 06.06.2016 sysdate 31.12.9999

33. 3333
Update future with infinity
Update record by value “B”, effect from 06.06.2016.

34. 3434
Update future with infinity
sysdate1
Valid
Know
01.01.2016
A

35. 3535
Update future with infinity
sysdate1
Valid
Know
01.01.2016
A
A
sysdate2
06.06.2016
B

36. 3636
Update future with infinity
Action Data Valid From Valid Till Known From Known Till
Update A - - - sysdate
Insert A 01.01.2016 06.06.2016 sysdate 31.12.9999
Insert B 06.06.2016 31.12.9999 sysdate 31.12.9999

37. 3737
Update the past with infinity
Update record by value “C”, effect from 03.03.2016.

38. 3838
Update the past with infinity
sysdate1
Valid
Know
01.01.2016
A
A
sysdate2
06.06.2016
B

39. 3939
Update the past with infinity
sysdate1
Valid
Know
01.01.2016
A
A
sysdate2
06.06.2016
B
sysdate3
C
03.03.2016

40. 4040
Update the past with infinity
Action Data Valid From Valid Till Known From Known Till
Update A - - - sysdate
Update B - - - sysdate
Insert A 01.01.2016 03.03.2016 sysdate 31.12.9999
Insert C 03.03.2016 31.12.9999 sysdate 31.12.9999

41. 4141
Update the past with close date after first update
Update record by value “C”, effect from 03.03.2016 to 09.09.2016.

42. 4242
Update the past with close date after first update
sysdate1
Valid
Know
01.01.2016
A
A
sysdate2
06.06.2016
B

43. 4343
Update the past with close date after first update
sysdate1
Valid
Know
01.01.2016
A
A
sysdate2
06.06.2016
B
sysdate3
C
03.03.2016 09.09.2016
B

44. 4444
Update the past with close date after first update
Action Data Valid From Valid Till Known From Known Till
Update A - - - sysdate
Update B - - - sysdate
Insert C 03.03.2016 09.09.2016 sysdate 31.12.9999
Insert A 01.01.2016 03.03.2016 sysdate 31.12.9999
Insert B 09.09.2016 31.12.9999 sysdate 31.12.9999

45. 4545
Update the past with close date before first update
Update record by value “C”, effect from 03.03.2016 to 04.04.2016

46. 4646
Update the past with close date before first update
sysdate1
Valid
Know
01.01.2016
A
A
sysdate2
06.06.2016
B

47. 4747
Update the past with close date before first update
sysdate1
Valid
Know
01.01.2016
A
A
sysdate2
06.06.2016
B
sysdate3
C
03.03.2016 09.09.2016
A A
04.04.2016

48. 4848
Update the past with close date before first update
Action Data Valid From Valid Till Known From Known Till
Update A - - - sysdate
Keep B - - - -
Insert C 03.03.2016 04.04.2016 sysdate 31.12.9999
Insert A 01.01.2016 03.03.2016 sysdate 31.12.9999
Insert A 04.04.2016 06.06.2016 sysdate 31.12.9999

49. 4949
When to use
Ask yourself two questions:
▪ Does your business need to know the situation as it was known at a particular
date?
▪ Does your business use information that was effective in the past or will become
effective in the future?
⇒ If you answer YES on one or both of these question then your data varies
over time and you could consider adopting a temporal approach.

50. 5050
Q&A

51. 5151

52. 5252
References
▪ http://www.datasciencecentral.com/profiles/blogs/temporal-databases-why-
you-should-care-and-how-to-get-started (3 parts)
▪ https://www.linkedin.com/pulse/emerging-data-design-bitemporal-mike-
lapenna (2 parts)
▪ Kudos to my ex-colleagues.

53. 5353
IT SecurityNEVISIT Consulting Application
Management
Software Solutions
Linh Chau, Software Engineer
linh.chau@adnovum.ch
www.adnovum.ch