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Dimension attributes, or new dimension

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Dimension attributes, or new dimension Empty Dimension attributes, or new dimension

Post  cjrinpdx Thu Aug 04, 2011 9:15 pm

I have a factless fact table that is used to track the relationships between events and employees. The event dimension has a city and state, as well as status, type, etc., that the users would like to slice-and-dice by in Excel. Are there any benefits of taking the city and state from the event and creating a location dimension; and adding the LocatioKey to the factless fact table? Thanks.

cjrinpdx

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Dimension attributes, or new dimension Empty Re: Dimension attributes, or new dimension

Post  BoxesAndLines Fri Aug 05, 2011 8:50 am

Yes, that is a better design. Text attributes in the fact table impact performance.
BoxesAndLines
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Post  VHF Fri Aug 05, 2011 10:01 am

Sounds like the City and State are already attributes in the Location dimension. The OP was was asking if there would a benefit to having a separate Location dimension.

My answer would be "no" for what you are doing now. Users can slice-and-dice using any attribute in any dimension. The only scenario I can think of where there would be some benefit to having Location be a separate dimension would be if there were other fact tables that related to Location. With a conformed Location dimension you would be able to drill-across fact tables if you wanted to compare event attendance with some other location-specific fact.

VHF

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Post  Jeff Smith Fri Aug 05, 2011 10:46 am

I like having a Geographic dimension what rolls up data by City, County, State. If Block Group is available, Block group to Census Tract, County, State is a nice hierarchy. If regions have been created, I usually add them to the geographic dimension.

If it's a stand alone dimension, it can be reused for other subjects such as, store locations, customers, etc. Which can be nice if you want to create a summary table with measures from multiple fact tables rolling up to geography.


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Post  cjrinpdx Fri Aug 05, 2011 12:45 pm

Thank you for your posts.
I do have other fact tables that relate to Location, so I will create a new Location dimension. Good point about creating a conformed Location dimension and using it to drill-across fact tables. Thanks again!

cjrinpdx

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