Implement Envers querying on top of SQL2011 versioned tables

[beikov]

The idea to support SQL2011 versioned tables, which came up on the JPA spec project in the past and the idea is interesting, because it could be a nice abstraction for Hibernate Envers to use.

I didn't give this too much thought yet, but I imagine the following:

• New annotation to mark versioned entities
• New HQL syntax to allow querying history data e.g. ('as' 'of' ('system time'|timestampExpression)|'versions' betweenPredicate)

The added benefit of Envers would be the possibility to fine tune columns/properties that should be audited as system versioning is an all or nothing thing. The AuditQuery API should be buildable on top of the new HQL syntax and there should be an SPI that Envers can plug into, to translate queries to the proper SQL.

[gavinking]

New HQL syntax to allow querying history data

Is that the right way to do it, or should it be more of a session-level setting like with filters?

[beikov]

Using filters instead would require that the user specifies for which from-node alias to enable a filter. This means that aliases would have to be globally unique. Also, what would be the solution for criteria queries since the nodes of criteria queries don't have aliases?

Not relying on aliases would be very limiting and would i.e. make it impossible to join history data against current data.