apparently there is another book in the market about data vault modeling. while it has some interesting notions, it also has some false claims about the nature of data vault modeling which need to be corrected. any time there is a disagreement between what’s available in the market (standards based) and what i produce as the standards, i would have to say that my standards are correct. particularly because i am the author and inventor of the data vault, and i have had years and years (since 1990) of r&d and implementation experience.
false claim #1: multi-active satellites are not ok
reality: multi-active satellites are ok, and are in fact a necessary part of surviving in data warehousing / data vaults. why? because the data set like phone numbers (which are described in my book super charge your data warehouse) are a part of incoming information. multi-active satellites can occur for a number of reasons, and the fact of the matter is: there just is no good resolution – except to go all the way to 6th normal form. in 6th normal form, you are very close to anchor modeling, and at that point you are no longer using data vault techniques.
false claim #2: events are hubs
reality: events 99.9% of the time are a cross between time, place, and object (person, service, or product). because of this, 99.9% of the time they have multiple business keys that they share, which means they *must* be modeled as links and link satellites (they cross multiple hub keys). if you model a relationship as a hub (as indicated by bar code and documented in the book), then that means you have a single business key representation for this event – it actually does have a true bk for it. modeling an event as a hub all the time would be incorrect, it does not always meet this criteria, and should not always be modeled.
most of the time, events represent a combination of business keys which mean a relationship is at work. any time a relationship is at work, the data should be modeled as a link with a link satellite.
false claim #3: when a link is not a link
links are always links, sorry to say, but see false claim #2 above.
if it’s about the data vault model, or implementation methodology, and it disagrees with any material i write, discuss, or publish – then please let me know by emailing me or responding to this post. i’ll be happy to research it, and discuss it with you.