"And the database world is moving towards scaling horizontally rather than vertically."

I think that's an oversimplification. Two counterpoints:

* Database systems will always need to make heavy use of locality. The speed of light means that synchronizing access over long distances (even medium distances -- light only goes about a foot per nanosecond) will always be a challenge.

* Multi-core means vertical scaling is back in (if by "vertical scaling" you mean "scaling on one box"), and probably for a while.

Postgres is doing an excellent job at both.

I do agree with the less-exaggerated point that postgres really needs to improve its multi-machine scaling. But it's far from a solved problem on any system under discussion.

postgres does horrible with multicore unless you have many concurrent pooled connections. fork-and-forget

I think you're referring to postgres's inability to use more than one core per query, which is true (or mostly true... there are quite a few helper processes that take on some of the work).

For many smaller queries, postgres does great on multi-core, and pgbouncer is a good connection pooler.

People still use SQLlite. Why? Because its suits a specific set of circumstances.

Postgres does the same---its an incredibly powerful database with a large suit of features that make application development both easy and sane. To the vast majority of projects where you won't outgrow a single server, it makes sense to use it.

You have obviously never used Oracle RAC .. :)