Temporality
Temporality in data warehousing refers to temporal data, which is data that is only valid for a proscribed time on a specified timeline. Temporal data can be defined by timestamps, timelines, and time slices.
The use of temporality in Yotilla is described in more detail in the relevant section of The Yotilla Workflow.
Timestamps
A timestamp defines a specific point in time, not a period of time. Two different types of timestamps are used in Yotilla:
Technical timestamps are generated by the system. For example:
- Load time
- Inscription time
Business timestamps are entered in the source system by the user. For example:
- Customer birth date
- Departure time for a flight
- Hiring time for an employee
Timelines and Time Slices
A timeline is the axis on which temporal events happen. Timelines can be specified by the source or generated by Yotilla.
A time slice is a section of a timeline in which the attributes of a specific business object do not change.
The timelines generated by Yotilla are the only ones that can be trusted.
Timelines Delivered By the Source
| Inscription Time | The time when the data arrived in the source system |
| External Stage Load Time | The time when the data was extracted from the source system into the external staging area |
Timelines Generated By Yotilla
| Load Time | The time when the data was loaded into the data warehouse landing zone |
| Insert time + Update time | The time when the data in a data warehouse table was inserted or updated |
For information about how to use timelines and time slices when configuring the sources, see Temporality Tab.
