Periodic snapshot fact table with large dimensions
<p>I have been asked to model a star diagram.<br>
I have 3 dimensions:  </p>

<ol>
<li>Date (day,month, year, week, quarter, ...)</li>
<li>place (500 distinct values)</li>
<li>Product (80k different products)</li>
</ol>

<p>The main question is how many items (products) are stored at the end of a day in every place.</p>

<p>After some study-time with regards to dimensional modeling. I think I should implement a <strong>Periodic snapshot table</strong>. However reading trough the Kimball Docs, I noticed that a periodic snapshot demands an entry for every combination of the dimensions. This means I should add <strong>40M</strong> rows every day (80k*500).<br>
Knowing that the products are (real) slow movers and that many places store <strong>zero</strong> products during long periods, this sounds like an extreme overkill.<br>
FYI the transactions in the source DB are 150k rows after three years.  </p>

<p>So should I really add 40M rows every day, or could I just add the non-empty stores with their products specified? Also if for whatever reason one day all stores are empty, should I make an entry for that day (with dimensions N/A for store and product)?</p>