I need to sort a collection with respect to a sorting criteria specified by the user.

Problem is everytime I sort the collection using Collections.sort(hibernateCollection)

Hibernate always recreates the associations when saved creating a new IDs everytime.

Sorting the collection shouldn't be a problem as long as the collection reference doesn't change. Can you post your mapping of this collection and possibly the code you are calling to save it?

I'm using a BAG for mapping and digging into the hibernate documentation, I found this from http://www.hibernate.org/hib_docs/refer ... ollections
Section 14.1.1

"Bags are the worst case. Since a bag permits duplicate element values and has no index column, no primary key may be defined. Hibernate has no way of distinguishing between duplicate rows. Hibernate resolves this problem by completely removing (in a single DELETE) and recreating the collection whenever it changes. This might be very inefficient."

This could be the reason why i'm seeing a single DELETE statement and a lot of INSERT statement in the Hibernate logs.