On Sep 21, 2006, at 10:51 AM, Wolfgang Keller wrote: >> mike wrote: >> if someone wants to write an extension, most easily to >> sessioncontext, that just synchronizes data between open sessions, >> thats not a big deal. But it really is somewhat of a reinvention of >> the database itself. the Session only represents the set of objects >> youre working on *right now*. if i wrote a function that loaded a >> row from a database, and then i was going to operate on some of those >> values, would i want those values to magically change while i was in >> the middle of my operation ? > > Err, no. However I do think that you should be notified that they > have been > changed by some third-party and then have the possibility to update > your > values if you want to. >
ok, and what sort of mechanism would be used for this notification ? if im inside of a python function, would there be some kind of interrupt mechanism being used, that yanks me out of my current code into some subroutine to deal with a change ? or would it be the job of the code itself to finish what its doing, and then before doing the next thing simply check for changes ? all this requires in the session-based model is to expire() all the objects contained within (or just clear it out, or get your objects using load(), etc. the session has many ways of going back to the database to get the latest data). the database then acts as the commonality between all open sessions. this is why building another layer of commonality between sessions in python is somewhat of a reinvention of the wheel; you can argue that its faster or more efficient than going back to the database, in which case its an optimization; but i wouldnt optimize and complicate before determining that the database itself is not fast enough. at this point, id like to see what you want your code to look like for your application to do what it needs. ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Sqlalchemy-users mailing list Sqlalchemy-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sqlalchemy-users
