We are planning to integrate hibernate 4 multi-tenancy feature into our application. With this feature I assume we would have only one session factory instance irrespective of the number of tenants. (right?). If so, would it lead to reduced heap usage or would the single session factory instance occupy the same amount of memory as multiple instances did before? Are there any other performance benefits with this integration? I wanted to get an understanding on this before starting with the actual implementation since it involves considerable code changes. Thanks!