Does numeric Visit ID go in a fact table?

View previous topic View next topic Go down

Does numeric Visit ID go in a fact table?

Post  BI Consultant on Tue Aug 09, 2011 5:15 pm

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!

BI Consultant

Posts : 18
Join date : 2011-08-09

View user profile

Back to top Go down

Re: Does numeric Visit ID go in a fact table?

Post  ohmycamote on Tue Aug 09, 2011 5:46 pm

Look at Factless Fact Tables - that might help you with your problem.

ohmycamote

Posts : 14
Join date : 2011-07-05

View user profile

Back to top Go down

Re: Does numeric Visit ID go in a fact table?

Post  BoxesAndLines on Tue Aug 09, 2011 8:00 pm

It is a degenerate dimension. Put it in the fact table. If it were character, the answer would be the same.
avatar
BoxesAndLines

Posts : 1212
Join date : 2009-02-03
Location : USA

View user profile

Back to top Go down

Re: Does numeric Visit ID go in a fact table?

Post  LAndrews on Wed Aug 10, 2011 1:23 pm

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.


LAndrews

Posts : 132
Join date : 2010-05-13
Location : British Columbia, Canada

View user profile

Back to top Go down

Re: Does numeric Visit ID go in a fact table?

Post  nutjob_29 on Wed Aug 10, 2011 1:34 pm

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

View user profile

Back to top Go down

Thanks!

Post  BI Consultant on Wed Aug 10, 2011 1:47 pm

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

View user profile

Back to top Go down

Re: Does numeric Visit ID go in a fact table?

Post  Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum