I think a lot of the scalability arguments between SQL and NoSQL has little to do with relational databases as a technology and a lot to do with "how to scale w

I think a lot of the scalability arguments between SQL and NoSQL has little to do with relational databases as a technology and a lot to do with "how to scale without paying for expensive software licenses". They miss that some of the largest commercial sites use commercial databases. Oracle, for example, to my understanding, is the standard database in use at Amazon.com for their services; there are alternatives for key services, but Oracle is pervasive (at least as of 2009, when I last had insight into this). Another interesting rumour I recently read (ymmv, of course): Apple runs the iTunes Music Store on Oracle's Exadata. Source is from a fairly trusted source in the Oracle DBA community (Daniel Morgan): http://forums.oracle.com/forums/thread.jspa?messageID=4255208&tstart=0 http://forums.oracle.com/forums/thread.jspa?messageID=425520... Clearly there are limitations to a shared-disk RDBMS or even a shared-nothing RDBMS, but the tech sphere somehow seems to be stuck looking only at the open source implementations of these things as the only "reality". For a startup, that's likely true, but for a larger company, there's a very different risk profile when evaluating a SQL vs. a NoSQL solution.