No, it isn't bad advice just overly simplified and generalised.
The vast majority of companies won't need to face scaling or big data issues, they're too busy going after that next sale to keep their heads above water. There are, however, some problems that require lots of data very early on so in these situations it's appropriate to look for solutions like MongoDB, CouchDB, Riak et al. What ends up happening all too often is someone hears about MongoDB being the best new cool thing and decides to implement their company CRUD + sales platform on top of it.
The question you have to ask yourself is why isn't Postgres suitable for you. That might be huge amounts of data and heavy reads and rapidly changing schemas that make MongoDB a better choice.
In any case this post was great because it shows that Postgres can scale if you're willing to put some money, thought and effort into it. I doubt many people here have Instagram's data size or scaling issues.
You'd be surprised. There are a lot of small to midsized companies with data-intensive products. There are a dozen different fleet-tracking-as-a-service companies, several thousand inventory-management, medical-billing management, etc.
The Silicon Valley Tech Bubble is not where the bulk of data usage happens.
Why are you thinking about this when you're not even sure that your app will need to run on multiple EC2 regions? This smells like premature optimisation to me.
The vast majority of companies won't need to face scaling or big data issues, they're too busy going after that next sale to keep their heads above water. There are, however, some problems that require lots of data very early on so in these situations it's appropriate to look for solutions like MongoDB, CouchDB, Riak et al. What ends up happening all too often is someone hears about MongoDB being the best new cool thing and decides to implement their company CRUD + sales platform on top of it.
The question you have to ask yourself is why isn't Postgres suitable for you. That might be huge amounts of data and heavy reads and rapidly changing schemas that make MongoDB a better choice.
In any case this post was great because it shows that Postgres can scale if you're willing to put some money, thought and effort into it. I doubt many people here have Instagram's data size or scaling issues.