[audioheavy]

My main takeaway from this article: as popular as Postgres and MySQL are, and understanding the legacy systems built for them, it will always require deep expertise and "black magic" to achieve enough performance and scale for hyper scale use cases. It justifies the (current) trend to have DB's built for distributed tx/writes/reads that you don't have to become a surgeon to scale. There are other DBs and DBaaS that, although not OSS, have solved this problem in a more cost-efficient way than having a team of surgeons.

[zie]

I would argue, you handle the hyper-scale use case when you are actually in hyper-scale. Trying to pre-maturely optimize this is almost always a waste of time and chances are you will screw it up anyway. Almost nobody gets to that scale anyway. If you do get to that scale, you have the money and resources to fix the problem(s) at that time.

[dalyons]

i mean, sort of? There is some subtly lost in this oft-repeated advice. i've worked at 3 companies now that were initially based on a single RDBMS but have outgrown the scale of what is reasonable to serve off that architecture. They are consumer scale (10s of mill) users, but not hyperscale (IMHO 100m+). The amount of engineering cost to migrate a complicated growing company/product off a mono-db architecture is astounding. Conservatively i'm talking 10+ dev years of effort, at each company. Easily 10s of millions of $$$, maybe 100m+. None of them are "finished". It's really really time consuming and hard, once you have 100s of tables, 100s of thousands of lines of code, dozens of teams, etc.

I'm all about avoiding premature optimization, and its fine to start with a classic postgres. But please don't cling to that - if you see MVP success and you actually have a reasonable chance of getting to >1mill users (ie, a successful B2C product) please please dont wait to refactor your datastore to a more scalable solution. You will pay dearly if you wait too long. Absolutist advice serves noone well here - it really does depend on what your goals are as a company.