* Jyoti Seth <[EMAIL PROTECTED]> wrote: Hi,
if you can live with some seconds lag, you can use an separate transfer process which looks at the source of your prices and and updates the second DB if some price changes. Depending on how often prices change, there're two good options: a) add an timestamp field to the original price table, which is maintained by an after-trigger. The transfer regularily (ie. every few secs) fetches all those records which have been changed since last poll (via the new timestamp field). b) create an new table for an journal of the price changes. this journal is filled by rules on the original table and contains exactly what's needed to reproduce the price changes in the other DB. The transfer process regularily fetches the journal and rolls it out in the second DB. I've implemented the method b) in an realtime stock (FOREX) trading applications where trading automatically robots execute transactions on the customer's broker accounts on signals provided by an team of profession traders. (the client can subscribe to several trading signal channels and define in which quantities transactions should be performed from which channels should be executed on their broker accounts and the broking platform does all the time critical work). The robots work entirely on separate databases (on separate hosts), several transfer processes feed in robot commands and fetch back results to the primary database. So time critical things are separated to own servers. It works quite fine :) cu -- --------------------------------------------------------------------- Enrico Weigelt == metux IT service - http://www.metux.de/ --------------------------------------------------------------------- Please visit the OpenSource QM Taskforce: http://wiki.metux.de/public/OpenSource_QM_Taskforce Patches / Fixes for a lot dozens of packages in dozens of versions: http://patches.metux.de/ --------------------------------------------------------------------- ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
