People always talk about nosql scaling better, but some of the largest websites on the internet are mysql based. I'm sure some people have problems where nosql is genuinely an appropriate solution, but i find it hard to believe that most people get anywhere near that level of scalability.
Exactly, and from a features standpoint Postgres can do everything Dynamo can do and so much more. I think a lot of software devs don't really know SQL or how RDBMS work so they don't know what they are giving up.
Postgres even has JSONB support, so if you really want to store whole documents NOSQL-style, you can - and you can still use all the usual RDBMS goodness alongside it!
Those very large mysql deployments typically use it as a nosql system, with a sharded database spread over dozens or hundreds of instances, and referential integrity maintained by the business layer, not by the database.
For a good example of a high volume site using a proper rdbms approach I would look at stackoverflow. It can (and has) run on a single ms sql server instance.
Even if that's so, still suggests rdbms are a good choice.
I do know for Wikipedia, english wikipedia is mostly a single master mysql db + slaves, with most of the sharding being on the site language level (article text contents stored elsewhere)
