Kimball Forum
Would you like to react to this message? Create an account in a few clicks or log in to continue.

Aggregate table columns

2 posters

Go down

Aggregate table columns  Empty Aggregate table columns

Post  jithindas Tue Feb 19, 2013 6:54 pm

Suppose if my fact table has 2 columns like cola and colb. And I have an aggregate table with colc and the value of colc is cola*colb from fct.
Is it better to do the calculations in fct and store and then move to aggregate or shall I this transformation while moving to aggregate table rather than storing it in fct table?


jithindas

Posts : 1
Join date : 2013-02-19

Back to top Go down

Aggregate table columns  Empty Re: Aggregate table columns

Post  ngalemmo Tue Feb 19, 2013 8:20 pm

The decision to create an aggregate is a matter of wither it will produce a significant performance enhancement over just using the atomic facts. With that decision made, do the calculation as part of the transformation into the aggregate. There is no need to store the value in the original fact, as there is no technical reason to do so and it would hamper performance of the original fact table by making it larger (assuming the transformation is as simple as you have expressed).
ngalemmo
ngalemmo

Posts : 3000
Join date : 2009-05-15
Location : Los Angeles

http://aginity.com

Back to top Go down

Back to top

- Similar topics

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