Data Warehousing and Business Intelligence

16 March 2011

Measures on a Dimension Table

Filed under: Data Warehousing — Vincent Rainardi @ 9:20 pm
Tags:

Recently I found a dimension table which had both attributes and measures. The reason for putting the measures in there was because they had the same grain as the dimension. I was thinking: was there a good reason why they should separate the measures into their own fact table? Several things that popped into my mind were:

  1. Was any “date” part of the grain? If so there could be an argument to break half of it (the measure columns) into a fact table, as this means there would be 2 dim key columns in the fact table: the main dim key and the date key (not only 1).
  2. There could be an advantage for ETL: we could truncate-reload the measures without affecting the dimension.
  3. And vice versa, we could treat the attribute as, for example, SCD 2 attributes, without affecting the measures.

As usual I welcome comments and discussion at vrainardi@gmail.com. Vincent 16/3/11.

Advertisements

Leave a Comment »

No comments yet.

RSS feed for comments on this post. TrackBack URI

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Create a free website or blog at WordPress.com.

%d bloggers like this: