Prolog doesn't care!
Read this, it shows how data will be organized:
You can download the PDF Plus (5758 KB),
See Figure 1.3: Storage hierarchy of a WSC.
Figure 1.4: Latency, bandwidth, and capacity of a WSC.
The above is the hardware aspect. The software aspect depends
on the application. They give one example, what could it be
else for Google, than its own search:
See 2.5.2 ONLINE: WEB SEARCH
But anyway I guess the usual tricks for data distribution work.
Vertical and/or horizontal partitioning of the data.
I am a little rusty, only have an old book in my shelf:
Principles of Distributed Database Systems
M. Tamer Ozsu and Patrick Valduriez,
see Section 5. Distributed Database Design,
5.3 Fragmentation, to get the idea.
http://www.springer.com/de/book/9781441988331
Maybe some products do it automatically now, dunno.
The links
hypertable.org spark.apache.org and
prevayler.org look rather shitty to me. Bla bla
we are the fastest, in what? Crashing the DB?
I must admit, I am more fan of Michael Stonebraker
and his PostgresSQL, what does the StormDB fork do?
http://www.postgres-xl.org/