问题
In short, what works faster:
- SessionFactory precompiling XML configuration, or
- Fluent NHibernate providing configuration programmatically ?
回答1:
Fluent NHIbernate creates the XML documents and Sessionfactory under the hood, so it is slower than not using Fluent NHibernate.
Why do you ask?
回答2:
My personal experience has been that the building of the Configuration object (which is unavoidable* regardless of whether Fluent is used) generally dwarfs the time required to setup a FluentConfiguration object, with the factor increasing as the number of mappings increase.
On a 2.5 Ghz c2d, with my project with approximately 15 mappings, it took 360ms for FluentConfiguration, and 5215ms for Configuration.
On a test project with 1000 mappings (simple classes with 2-3 string properties), it took 470ms for FluentConfiguration, and 40336 (40 seconds!) for Configuration.
*Actually, not really. most of the cost of Configuration comes from validating the XML mappings. Ayende has discussed it here (as well as a quick speedup obtained from merging the mappings into a single file), and a possible alternative to building the configuration at application startup is to serialize it as discussed here. In the 1000-mapping test project, this reduced the time required to get a Configuration object to around 30ms (although it has also increased the time required to build the SessionFactory from ~3 to ~4 seconds - I am unsure why).
来源：https://stackoverflow.com/questions/1625597/is-there-any-data-on-nhibernate-vs-fluent-nhibernate-startup-performance