Nested Transactions: Reviewing the Coherence Contract

Abstract In this paper we review nested transactions from the coherence point of view. We present the contract that has to be established between a distributed database system and its nested transaction programmers, in order to achieve database coherence. Terms of the contract are described through the underlying properties of nested transactions, which we define as nested-all-or-nothing, nested-consistency, nested-isolation , and nested-durability . By providing a precise semantic of nesting, these properties enhance the safe use of nested transactions in distributed database systems.