No, it's definitely set by the DB. For our Oracle servers, it's read-committed. I've checked this with code to make sure (I can do so again if no-one believes me :-)
Regardless, Dave's points still hold - cftransaction works across all DB sessions, across all connections. What it you have two CF servers hitting the DB at the same time? CFLOCK won't help. What if someone is using an entirely different server system against your DB at the same time? etc. Unless the app is under extreme load, a read-committed transaction will generally do the job. On 9/12/07, Dave Watts <[EMAIL PROTECTED]> wrote: > > According to livedocs cftransaction by default uses the > > default isolation level of the database - which in most > > installations will be either read committed or repeatable > > read. > > This has come up before; I believe that this may be a documentation error. I > recall receiving an email about this from Macromedia tech support saying > that the default isolation level for CFTRANSACTION was SERIALIZABLE, but > since I'm away from my email archive I can't get it now. I'll try to follow > up on this when I return. > > But in any case, in the majority of instances where people use > CFTRANSACTION, READ_COMMITTED would be sufficient to prevent data integrity > problems/logical errors/race conditions, and it would still be preferable to > using CFLOCK. > > > What you say is true if one sets the isolation level > > explicitly to serializable. However (I'm sure you know this > > but it's worth saying), it's hard to overstate the crippling > > effect on database throughput that serializable transactions > > can have. I would recommend that even for lightly loaded > > sites it's worth the extra effort to put a locking strategy > > in place using cflock, and save serializable transactions for > > "stop the world" database maintenance tasks. > > When you want to prevent any concurrent access to database objects, you want > to use serializable transactions. Of course, like any sort of locking, the > more restrictive the lock the greater the potential bottleneck, but > serializable transactions do have an important place in many applications - > and not just for maintenance purposes. -- mxAjax / CFAjax docs and other useful articles: http://www.bifrost.com.au/blog/ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Download the latest ColdFusion 8 utilities including Report Builder, plug-ins for Eclipse and Dreamweaver updates. http;//www.adobe.com/cfusion/entitlement/index.cfm?e=labs%5adobecf8%5Fbeta Archive: http://www.houseoffusion.com/groups/CF-Talk/message.cfm/messageid:288243 Subscription: http://www.houseoffusion.com/groups/CF-Talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4
