We've hooked up the ISaveOrUpdateEventListener event and hoped we could tie it to a progress bar update for each node being visited during the save traversal of a pretty big model, BUT the event only fires once when the save operations starts (only on the node on which the Save( ) was inititated and not on any subnodes).
Are there any other events that are more appropriate to listen to for this?
We've also tried breaking up the save operation (of a hierarchical model) by doing the traversal ourselves, but that seems to degrade the performance even further.
Perhaps we're trying to solve a problem for which FNH wasn't aimed to be used. We're new to it.
We've also set up an alternative solution using SqlBulkCopy, as recommended elsewhere.
We've seen the comments that FNH is primarily supposed for smaller transactions (OLTP) and not the type of exhaustive model we're bound to by our problem (signal processing of huge data volumes).
We're trying to use Fluent NHibernate on a larger database project with data gathered from fairly complex real time analysis (high frequency, multiple input signals, long experiment times etc). In a prototype we've built we see pretty scary wait times for the moment, and need to hook in some sort of reliable progress indicator.
Yes, now confirmed - as mentioned in my comment above. One (possible) solution to this is to simply turn of Cascades and do the model traversal manually and do explicit Save( ) calls.
This works, although it's not as neat as just handling an event. Still, given the genuin design of NHibernate, I bet there's certainly an event somewhere that could be intercepted - the question is just under what name. ... I bet someone on here knows more.
Also to improve performance we used a Stateless Session, experiemented with differnet batch size, and periodically/explicitly call Flush() and Clear(). See articles below for further details:
Hope this helps.