memory-efficient storage of large data on disk and fast access
functions
Daniel Adler <dadler@uni-goettingen.de>, 
	Christian Gläser <christian_glaeser@gmx.de>,
	Oleg Nenadic <onenadi@uni-goettingen.de>, 
	Jens Oehlschlägel <Jens.Oehlschlaegel@truecluster.com>,
	Walter Zucchini <wzucchi@uni-goettingen.de>