<p>We wrote a research paper that seems relevant:</p>

<p>Kamel Aouiche and Daniel Lemire, A Comparison of Five Probabilistic View-Size Estimation Techniques in OLAP, DOLAP 2007, pp. 17-24, 2007. 
<a href="http://arxiv.org/abs/cs.DB/0703058" rel="nofollow">http://arxiv.org/abs/cs.DB/0703058</a></p>
How to calculate the likely size of an OLAP cube
<p>Does anyone know a method to use to get a rough size of an OLAP cube based on a star schema data warehouse. Something based on the number of dimensions, the number of records in the dimension tables and the number of fact records and finally the number of aggregations or distinct records etc..</p>

<p>The database I am looking at has a fact table of over 20 billion rows and a few dimension tables of 20 million, 70 million and 1.3 billion rows.</p>

<p>Thanks
Nicholas</p>