[rmaccloy]

PostgreSQL has gained many nice features (windowing queries, parallel restore, moving towards more standardized master/slave replication, etc), but none of them have substantially affected its suitability as a high-throughput/large-data/(relaxed-consistency)/low-latency datastore. (On the other hand, it has become significantly nicer for BI/OLAP workloads.)

Same for MySQL, modulo (possibly) the Drizzle project.

Oracle has a lot of different irons in the fire, but "cheap scaling" isn't one of them. (If you've got the money to burn... TimesTen?)

That's not a knock on any of the above, it's just a different use case.

[cturner]

Vertica is designed for scaling. That's based on postgresql and under active development to that end.

[rmaccloy]

So is Greenplum (more so, actually.)

Neither are useful for the Digg usecase. Edit: That is to say, they're optimized for large datasets, low concurrency, medium latency, medium-to-high consistency and medium-to-low availability.