see org.hibernate.test.annotations.embeddables.EmbeddableIntegratorTest this test is using Integrator to registerTypeOverride, in the middle of SF initializing, after Configuration / Metadata built. so, firstly I want to confirm if this is an expected use case of Integrator, since at this time, the metadata is supposed to resolved, and no way to apply the new overrided types. ( This test passes w/ Configuration, since the attribute type is delayed to the persister initialize time, and the Value holds a reference of org.hibernate.cfg.Configuration.MappingsImpl, which holds a reference to the Configuration#typeResolver. but this also doesn't sound right, since SF also has a typeResolver, which is a copy of Configuration#typeResolver, and it is copied before the Integrator applied. ) the process looks like: 1. Configuration creates a new instance of TypeResolver and load default types ( including dialect overrided types and org.hibernate.metamodel.spi.TypeContributions ) 2. SF create a new instance of TypeResolver and copy all types from Configuration.typeResolver 3. apply integrator and add/override new types to the Configuration.typeResolver, here we get mismatch between SF.typeResolver and Configuration.typeResolver I checked the git history / JIRA and trying to find the background of this test, but nothing. if you guys confirm this is not a valid use case, then I'd suggest: 1. give Integrator a better name and clearly add something to the (java) doc say the expect usage of this Integrator ( maybe DO NOT TRY TO CHANGE THE STATE OF METADATA / CONFIGURATION AT THIS SATGE?) 2. move the IntegratorService to the SessionFactoryServiceRegistry? ------------------------- Best Regards, Strong Liu <stliu at hibernate.org> http://about.me/stliu/bio