Take a look at data virtualization. It&#x27;s an alternative to data warehousing without the burden of making mutiple copies of the data; instead, it retrieves the information fron source systems in real time.<p>The &quot;single view of customer&quot; use case, which is the one you mention in your post, is one of the oldest that this technology aimed to solve and it does solve it very well.<p>Disclaimer: I work for Denodo (<a href="http:&#x2F;&#x2F;denodo.com" rel="nofollow">http:&#x2F;&#x2F;denodo.com</a>).