Implementing orthogonal persistence: a simple optimization using replicating collection

Orthogonal persistence provides a safe and convenient model of object persistence. We have implemented a transaction system which supports orthogonal persistence in a garbage collected heap. In our system, replicating collection provides efficient concurrent garbage collection of the heap. In this paper, we show how replicating garbage collection can also be used to reduce commit operation latencies in our implementation. We describe how our system implements transaction commit. We explain why the presence of nonpersistent objects can add to the cost of this operation. We show how to eliminate these additional costs by using replicating garbage collection. The resulting implementation of orthogonal persistence should provide transaction performance that is independent of the quantity of nonpersistent data in use. We expect efficient support for orthogonal persistence to be valuable in operating systems applications which use persistent data