[pgsql-www] technical updates to postgresql.org (db size / parallell query)

https://www.postgresql.org/about/
|There are active PostgreSQL systems in production environments that manage in
|excess of 4 terabytes of data.

I think that gives the impression that PG isn't regularly used with larger
data, and should either be removed or (periodically) updated.  I don't expect
we're near the technical or other limitations, but at least two of our
customers have DBs currently 10-20TB and continuing to grow.

https://wiki.postgresql.org/wiki/FAQ#How_does_PostgreSQL_use_CPU_resources.3F
|The PostgreSQL server is process-based (not threaded), and uses one operating
|system process per database session. A single database session (connection)
|cannot utilize more than one CPU. Of course, multiple sessions are
|automatically spread across all available CPUs by your operating system. Client
|applications can easily use threads and create multiple database connections
|from each thread.
|
|A single complex and CPU-intensive query is unable to use more than one CPU to
|do the processing for the query. The OS may still be able to use others for
|disk I/O etc, but you won't see much benefit from more than one spare core. 

I think should mention that PG96 introduces parallel query.
https://www.postgresql.org/docs/9.6/static/parallel-query.html

Justin