reads which modify data
hakan eryargi <[email protected]>
| Newsgroups | gmane.comp.java.prevayler |
|---|---|
| Message-ID | <[email protected]> |
hello, how would you design a system where some reads modify the data in an undeterministic way ? undeterministic means random here and can be translated into a deterministic one by supplying random seed from outside. one can say, these are actually writes not reads, so must be handled as transactions. the answer is there are so many of them so we cannot simply afford handling them as transactions. and a very very little proportion of that reads cause such random modifications. these reads trigger lazy calculations as described in this thread: http://www.nabble.com/Re%3A-execution-order-of-queries-and-transactions-p17049169.html continuing the sample in that thread: think of a moving entity. a write operation modifies its acceleration and direction, read operation calculates current velocity and position and returns them. no matter how many times you read the velocity, it will be the same at some specific point in time. it's ok till now. now add another feature that when entity's velocity drops to zero it takes some random damage. so when velocity or position is read, there is a chance that this will trigger a damage. how would you persist such a system with prevayler ? regards, r a f t ------------------------------------------------------------------------------ Open Source Business Conference (OSBC), March 24-25, 2009, San Francisco, CA -OSBC tackles the biggest issue in open source: Open Sourcing the Enterprise -Strategies to boost innovation and cut costs with open source participation -Receive a $600 discount off the registration fee with the source code: SFAD http://p.sf.net/sfu/XcvMzF8H _______________________________________________ To unsubscribe go to the end of this page: http://lists.sourceforge.net/lists/listinfo/prevayler-discussion _______________________________________________ "Databases in Memoriam" -- http://www.prevayler.org