Re:Billing systems are a nightmare for engineers
by janci on Wednesday May 18, 2022 @11:57PM
(#31430545)
Not DB2, but the meaning is the same.
In a time-series (or event) table you have one date - when the data point is valid (event occurred).
In a temporal table you have two dates - interval when the data is valid.
In a bitemporal table you have two intervals. First describes when the data is valid in real world, the second when does the system know about the real-world state.
I.e. if company changed address on 2022-05-01 but the system will not get that information until three day later (2022-05-03) you have two validity intervals.
Then you may ask - what was the company address on 2022-05-02? And what did the system think the address was on 2022-05-02? You will get two different answers. This is important if you need e.g. to make a correction to previously issued invoice. You need to know what data was used for original invoice and what data should have been used.
In a time-series (or event) table you have one date - when the data point is valid (event occurred).
In a temporal table you have two dates - interval when the data is valid.
In a bitemporal table you have two intervals. First describes when the data is valid in real world, the second when does the system know about the real-world state.
I.e. if company changed address on 2022-05-01 but the system will not get that information until three day later (2022-05-03) you have two validity intervals.
Then you may ask - what was the company address on 2022-05-02? And what did the system think the address was on 2022-05-02? You will get two different answers. This is important if you need e.g. to make a correction to previously issued invoice. You need to know what data was used for original invoice and what data should have been used.