Literally the first line of every line on the site:

> PlanetScale is the world’s fastest relational database platform. We offer PostgreSQL and Vitess databases that run on NVMe-backed nodes to bring you scale, performance, reliability, and cost-efficiencies — without sacrificing developer experience.

> PlanetScale is a relational database platform that brings you scale, performance, and reliability — without sacrificing developer experience.

> We offer both Vitess and PostgreSQL clusters, powered by locally-attached NVMe drives that deliver unlimited IOPS and ultra-low latency.

> PlanetScale Metal is the fastest way to run databases in AWS or GCP. With blazing fast NVMe drives, you can unlock unlimited IOPS, ultra-low latencies, and the highest throughput for your workloads.

> The world’s fastest and most scalable cloud databases PlanetScale brings you the fastest databases available in the cloud. Both our Postgres and Vitess databases deliver exceptional speed and reliability, with Vitess adding ultra scalability through horizontal sharding.

> Our blazing fast NVMe drives unlock unlimited IOPS, bringing data center performance to the cloud. We offer a range of deployment options to cover all of your security and compliance requirements — including bring your own cloud with PlanetScale Managed.

Ironically, the _how_ is a major topic of the very page you started on (the blog).

Have some agency.

This isn’t any kind of answer it’s a bunch of non-statements..

How is this any different that rds on nvme disks?

With a name like planet scale i assumed it would be some multi-master setup?

sharded setup with a bit fast and loose foreign key management, so very good for performance but not a drop-in replacement if you rely on your foreign keys to be constrained/checked by the database.

So perfect for most web dev companies, then.

“We handle FKs in the app for flexibility.”

“And how many orphaned rows do you have?”

“…”

The question isn't how many orphaned rows do you have, it's whether it matters. Databases are wonderful but they cannot maintain every invariant and they cannot express a whole application. They're one tool in the belt.

> cannot express a whole application

Not with that attitude: https://docs.postgrest.org/en/v13/index.html

Orphaned rows can very much matter for data privacy concerns, which is also where I most frequently see this approach failing.

Most companies can afford not to give a shit until they hit SOC2 or GDPR compliance and then suddenly orphaned data is a giant liability.

Planetscale used to run postgres on AWS with network attached storage. So every time the DB hits the disks > it goes over the network. Need to read 4kb > network, another 4kb > network. So your latency is instead of microsecond on local storage, its miliseconds. Where a local NVME can do ... 100k 4k reads, over the network storage it does maybe 1k (just a example).

The problem is, there are not a lot of solutions to scale postgres beyond a single server. So if your DB grows to 100TB ... you have a issue as AWS does not provide a 100TB local NVME solution, only network storage.

Here comes Niki or whatever they named it. Their own alternative to Vitess (see Mysql), what is a solution that allows Mysql to scale horizontally from 1 to 1000's of servers, each with their own local storage.

So Planetscale made their own solution, so they can horizontal scale dozens, hundreds of AWS VPS with their own local storage, to give you those 100, 200, 500TB of storage space, without the need for network based storage.

There are other solutions like CockroachDB, YukubyteDB, TiDB that also allow for horizontal scaling but non are 100% postgres (and especially extensions) compatible.

Side node: The guy that wrote Vitess for Mysql, is also working on multigress (https://multigres.com/), a solution that does the same. Aka Vitess for postgres.

So yea, hope this helps a bit to explain it. If your not into dealing with DB scaling, the way they wrote it is really not helpful.

> Side node: The guy that wrote Vitess for Mysql, is also working on multigress (https://multigres.com/), a solution that does the same. Aka Vitess for postgres.

And also was the founder of planetscale

The short answer is that RDS doesn't run on local NVMe disks, it runs on EBS.

I would just point out that its Hosted Postgres. If your looking for a how I think you have the wrong mental model. Its hosted Postgres, there are some nuance there as to why it would perform differently from RDS on Amazon, or CloudSQL on GCP, but its not some novel new technology that needs a long description.

If you are interested in their new technology that extends on hosted postgres check out Neki https://www.neki.dev/

Well, above the fold in the chapter 'What is PlanetScale for Postgres?' the second paragraph mentions custom operator. That makes me assume it is kubernetes.

it is kubernetes