Hi, By a thought that I have expressed to Niels as alternative for [the-idea-that-i'm-not-going-mention-here]. I was wondering how much work it would take to make MonetDB to work directly on fixed size files. I'm not going into details but anyone with a bit computer experience would know what fixed size files are in an operation system perspective. Would it be feasible to memory map directly to a disk instead, or would this potentially harm the performance with respect to transactions? With the storage method that I have in mind the backend would make absolutely sure the file is stored bit correct. Stefan ps. After writing this mail I have realized this could be applied on the two different projectes we discussed.