On Sep 12, 2007, at 11:29 PM, Michael Watkins wrote: > Incidentally, I did some very limited testing (more throwing mud at > the wall than anything) of a 5M object Durus with either Shelf or > File storage and didn't come away from that noticing much in the way > of surprising differences. It might be I wasn't paying attention > though... what ought one expect to see with the newer ShelfStorage? After the ShelfStorage is packed, you should see a huge difference. ShelfStorage does not load the packed index at startup or ever, so the 100 bytes per object rule only applies to objects commited since the last pack. Since packing can happen at any time on a live server, this means that the memory footprint and startup time of shelf storage is reduced to essentially constant time: you can have a billion objects in a packed ShelfStorage database and startup time will still be very small. The only thing startup does on a packed ShelfStorage is read the headers of the file and determine the one offset of the start of the packed index.