Does numeric Visit ID go in a fact table?
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Does numeric Visit ID go in a fact table?
I'm new to dimensional modeling, and need help understanding an entry to a fact table. I have an Fact table called "Ship_Arrival_Fact", and a fact row gets one entry each time a ship visits a channel (i.e. each time there's one visit). I need a Visit ID to identify each visitation, but I guess the Visit ID field won't go in any dimension. It's a numeric, but is not additive, that is, it's just an ID like 1234. From Kimball DW toolkit, I understand all fact table entries should be measurements.
Please advise where to place this Visit ID.
Thanks in advance!
Please advise where to place this Visit ID.
Thanks in advance!
BI Consultant- Posts : 18
Join date : 2011-08-09
Re: Does numeric Visit ID go in a fact table?
Look at Factless Fact Tables - that might help you with your problem.
ohmycamote- Posts : 14
Join date : 2011-07-05
Re: Does numeric Visit ID go in a fact table?
It is a degenerate dimension. Put it in the fact table. If it were character, the answer would be the same.
BoxesAndLines- Posts : 1212
Join date : 2009-02-03
Location : USA
Re: Does numeric Visit ID go in a fact table?
I'll echo what BoxesAndLines said - treat it as a degenerate dimension.
Since it is an ID, you may want to convert it to a chararacter string as well - some BI tools will assume that all numeric fields are measures and automatically try and summarize the column.
Since it is an ID, you may want to convert it to a chararacter string as well - some BI tools will assume that all numeric fields are measures and automatically try and summarize the column.
LAndrews- Posts : 132
Join date : 2010-05-13
Location : British Columbia, Canada
Re: Does numeric Visit ID go in a fact table?
Its a degenrate dimension.. it can be placed in fact table.. there is no corresponding dimension table of attributes associated with it..
nutjob_29- Posts : 1
Join date : 2011-08-10
Location : Los Angeles
Thanks!
Thanks for all the replies! I guess I'll place it in the fact table and treat it as a degenerate dimension.
BI Consultant- Posts : 18
Join date : 2011-08-09
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