Very Small Dimension Table
2 posters
Page 1 of 1
Very Small Dimension Table
While modeling the star schema for a construction project I came across a dimension which has only 3 values (Approved , Not Approved, Approval in Progress). I was wondering is it normal to have a dimension with only 3 rows or should I put them in the fact.
Thanks
Thanks
KKumar- Posts : 22
Join date : 2011-07-29
Re: Very Small Dimension Table
You don't want to put descriptive columns into a fact table. It burns up a lot of space and slows queries. You may want to consider combining this attribute with similar status information in a junk dimension, reducing the number of dimension tables.
Re: Very Small Dimension Table
I thought of having a junk dimension but I don't have any other attribute other than the approval indicator. So the junk dimension will have only 2 attribute - a surrogate key and approval indicator. Is that ok?
KKumar- Posts : 22
Join date : 2011-07-29
Re: Very Small Dimension Table
It's ok, and a 'pure' solution. But, for practical purposes, if you are taking about a single character field and have no need for other information (no description or other attributes) then making it a degenerate dimension on the fact is the way to go. Given there are a fixed and small number of possible values that are well understood, there is no need for the DW to house additional information. That can easily be handled by supplementing the BI layer with enumerated descriptions and other information.
For example you can simply put such information (descriptions, etc...) in a table whose PK is the code. It would not be a "dimension" but rather a lookup table the BI layer can use to provide more information.
For example you can simply put such information (descriptions, etc...) in a table whose PK is the code. It would not be a "dimension" but rather a lookup table the BI layer can use to provide more information.
![-](https://2img.net/i/empty.gif)
» Too many small dimension tables
» Fact table granulartity to small or just built wrong
» Pros and cons of consolidated dimension table Vs. many dimension table ?
» joining dimension table to dimension and again fact table
» Can a dimension table directly link to another dimension table?
» Fact table granulartity to small or just built wrong
» Pros and cons of consolidated dimension table Vs. many dimension table ?
» joining dimension table to dimension and again fact table
» Can a dimension table directly link to another dimension table?
Page 1 of 1
Permissions in this forum:
You cannot reply to topics in this forum