kdb+ also supports Petabyte distributed databases. i.e. much larger than RAM.<p>E.g. <a href="http:&#x2F;&#x2F;kparc.com&#x2F;q4&#x2F;readme.txt" rel="nofollow">http:&#x2F;&#x2F;kparc.com&#x2F;q4&#x2F;readme.txt</a> (Trillion Row Benchmarks)