What about sequences? The example shows an auto-incrementing user ID. How’s that possible without contention between all shards? Is the proxy responsible for sequences?

What about foreign keys? Do they all have to live on the same shard? How do you do distributed transactions?

On cross-shard reads: how do you do sorting? And cross-shard joins?

I’d love to be proven wrong, but I suspect the 768 servers look like 1 only on the very surface, and you’ll get wildly different characteristics from cross-shard and single-shard queries.

I personally would prefer if they _didn’t_ look like 1 if they can’t behave like 1.

Of course 768 servers NEVER behave as 1. This is physically impossible.

Global services using relational dbs typically severely restrict queries that run against the cluster. So no joins, no intervals, no grouping, etc.

Transactional queries are usually limited to something like "get a single record, preferably from cache". For many typical web services this can go VERY FAR. Only a handful of global services needs more than a few dozen database servers and a caching cluster. In fact, i have seen major businesses running off a pair of very big postgres instances.

Analytical stuff is extracted into dedicated storages optimized for throughput, like Snowflake or Redshift or BigQuery.

A 767 servers KV store should be enough for everyone