Related: Oxide's podcast, "Whither CockroachDB," which reflects on experience with postgres at Joyent, then the choice to use cockroach in response to prior experiences with postgres.

https://www.youtube.com/watch?v=DNHMYp8M40k

I'm trying to avoid editorializing in my above summary, for fear of mischaracterizing their opinions or the current state of postgres. Their use of postgres was 10 years ago, they were using postgres for a high-availability use case -- so they (and I) don't think "postgres bad, cockroach good." But like Bryan Cantrill says, "No one cares about your workload like you do." So benchmark! Don't make technical decisions via "vibes!"

Here you go https://www.uber.com/en-CA/blog/postgres-to-mysql-migration/

I think your point still stands, and I'm a big Postgres advocate/user myself btw.

But yeah we did migrate our _analytics_ data to ClickHouse (while still keeping Postgres for more transactional stuff) back when I was at PostHog.

Writeup: https://posthog.com/blog/how-we-turned-clickhouse-into-our-e...

Not an article, and I have no direct knowledge of this either way, but I would strongly suspect that Instagram migrated off Postgres a while back. Probably to fb-mysql + myrocks, or some other RocksDB based solution.

The compression level is vastly superior to any available Postgres-based solution, and at Instagram’s scale it amounts to extremely compelling hardware cost savings.

Also if they were still primarily on pg, it would be one of the largest pg deployments in existence, and there would be obvious signs of the eng impact of that (conference talks, FOSS contributions, etc).

Bigger-picture: Postgres is an amazing database, and it’s often the right choice, but nothing in tech is always the best choice 100% of the time. There’s always trade-offs somewhere.

Probably a corollary of the fact that most usecases can be served by an RDBMS running on a decently specced machine, or on different machines by sharding intelligently. The number of usecases for actual distributed DBs and transactions is probably not that high.

I helped with the initial assessment for a migration from Postgres with Citus to SingleStore.

https://www.singlestore.com/made-on/heap/

We migrated from postgres to ADX based on cost analysis done of the managed version on Azure.

Now we have lovely kql queries and pretty much start new with postgres again...

I have participated in a Postgres -> Clickhouse migration, but I haven't bothered writing an article about it.

Roughly the same count as migrating from Postgres to X.