Temporal database
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Small introduction about how to manage varying data.
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Temporal database
- 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.
- 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.
- 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”
- 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.
- 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