Data Vault Core Constructs by Data Vault Academy
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- Опубликовано: 18 фев 2012
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Very well explained, cleared the core concepts in such a short video
When I had my first project with Data Vault I nearly lost my mind but now I understood it
Thank you very much for this video
What about the satellites attached to the links. How it is captured if a link between two hubs is changing over time?
There's an error in your H_Class hub's surrogate key, it should be H_Class_SID instead of H_Customer_SID.
Glad someone with sharp eyes caught this small error as well. It confused me but at the same time made me doubt whether it was correct. I think he copied the same hub twice and forgot to adjust the name in the right hub. Thank you!
Very complicated terms for very simple things.
In DV seems that only SATs tables keep scd2 historic right ? How we track LINKs changes then ?
Example, imagine 2 HUBs and 1 LINK representing How many CARs a PERSON have.
in 20100101 Bob had 2 cars A and B, but then in 20200101 Bob only have 1 new car C or just kept A or B
I guess since in DV we only INSERTs happen, i guess LINK table would in reality look like:
REAL_TS hub_person hub_car
20100101 bob A
20100101 bob B
20200101 bob C
meaning we still could select current cars by checking max(REAL_Timestamp) and/or check historic over dates like count(*) over partition by PERSON.
Is this a good interpretation ?
No, a timestamp in a link only says when the relations was first loaded into the dw. You should attach a RTS to the link to be able to extract the data your are looking for.