On Wed, 2006-12-27 at 18:13 +0000, Tomi N/A wrote: > 2006/12/27, [EMAIL PROTECTED] <[EMAIL PROTECTED]>: > > Hi everybody, > > I'm looking for a database system for a SCADA system. The major > > probles I think it's on performance because the application it's going > > to poll about 4k variables per second from hardware and has to register > > the values on the procces table. > > I heard that PostgreSQL provides a bulk loading mechanism called COPY, > > which takes tab-delimited or CSV input from a file. Where COPY can be > > used instead of hundreds or thousands of INSERTS, it can cut execution > > time. > > I'm less than a novice so I'll thank any piece of advice. > > I believe you could easily simulate the load in a small > fake-SCADA-program and see how the hardware at your disposal handles > it with postgresql, a different RDBMS or simply a flat file. Make a > small program which will generate a set of 4k random values and send > them asynchronously over the network to your data acquisition > application which should store the data in the database. Measure how > fast you can send the data and still record everything.
If you are going to have a live feed you would probably benefit from the multi insert capability of 8.2: insert into foo values () () () Sincerely, Joshua D. Drake > > If data acquisition speed is your primary concern (as it seems to be), > you might want to use a simple .csv file: you'll probably beat the > performance of any database management system. You could periodically > move the saved data from the .csv files into a database (say, > postgresql) where you could (I assume) analyze it. You might want to > use a separate machine for the database management system so as to > remove any unnecessary CPU and I/O disturbances from the primary data > storage machine. > I don't think your load (32 kBps if your variables are double > precision float values) is a challenge, but running any kind of > analysis on a basically real-time-response-constrained machine might > cost you data losses and I don't know if you can afford those. > > Cheers, > t.n.a. > > ---------------------------(end of broadcast)--------------------------- > TIP 4: Have you searched our list archives? > > http://archives.postgresql.org/ > -- === The PostgreSQL Company: Command Prompt, Inc. === Sales/Support: +1.503.667.4564 || 24x7/Emergency: +1.800.492.2240 Providing the most comprehensive PostgreSQL solutions since 1997 http://www.commandprompt.com/ Donate to the PostgreSQL Project: http://www.postgresql.org/about/donate ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
