On Mon, 2012-06-11 at 11:38 +0200, Li Li wrote: > yes, I need average query time less than 10 ms. The faster the better. > I have enough memory for lucene because I know there are not too much > data. there are not many modifications. every day there are about > hundreds of document update. if indexes are not in physical memory, > then IO operations will cost a few ms.
I'm with Michael on this one: It seems that you're doing a premature optimization. Guessing that your final index will be < 5GB in size with 1 million documents (give or take 900.000:-), relatively simple queries and so on, an average response time of 10 ms should be attainable even on spinning drives. One hundred document updates per day are not many, so again I would not expect problems. As is often the case on this mailing list, the advice is "try it". Using a normal on-disk index and doing some warm up is the easy solution to implement and nearly all of your work on this will be usable for a RAM-based solution, if you are not satisfied with the speed. Or you could buy a small & cheap SSD and have no more worries... Regards, Toke Eskildsen
