On Wednesday 17 August 2005 10:57, David Van Couvering wrote: > BTW, what kind of application do you have that doesn't require the data > to be persistent over a memory failure? > Thats a good question, there are several scenarios that this could be applied. (I'll give you an example shortly...)
The purpose of the discussion was to see if there were some simple hardware tricks that could be used to improve performance. Considering the order (fastest to slowest): Ram Drives would be the fastest storage/retrival system. Bubble Memory / Flash Memory/ Memory sticks would be second. 10K RPM drives (High end scsi) would be the third, 7200 RPM drives (SATA, SCSI, IDE) would be the fourth. Ram drives are the fastest but have the greatest risk due to their need to constant power. The real question is that if we keep the database schema, transaction type, and transaction volume constant across these different types of media, we should see a performance difference. (Also trying to keep the amount of memory and other system stuff as constant as possible too.) There are a couple of applications where you would want to put a portion of your database on high speed "persistent memory" storage. (You can see this in financial applications for example, or in some telemetry systems where you have high capture rates of important information.) There are a couple of ways to achieve this, however, the idea of using a flash card or memory stick does offer some interesting alternatives that are at a potential price point. Using a financial system example... You want to create a system which captures trades in real time and then performs some calculations on the trade and some caputred data. You can do this in memory since you're splitting the incoming feed to your persistant storage unit. If your trading system fails, you restart the real time feed and then reload the persistant data and resume trading. (In that order.) With respect to a FOB or memory stick, there are some interesting applications too. -- Michael Segel Principal MSCC (312) 952-8175
