1. A method of persistence management in a data processing system, comprising: defining in memory of a computer, a desired level of reliability specifying a degree of a risk by specifying policy information by an end user; receiving a request for an operation on a data item from an application for carrying out a business transaction; determining that more than one type of policy information is applicable to the data item to be persisted; resolving any differences between the more than one type of applicable policy information; determining a persistence policy of a persistence data store storing persisted data associated with the operation from the received request, the persistence policy being based upon pre-defined data entered by a user within the application and specifying how and when to store data in the persistence data store so as to achieve the desired level of reliability; performing the requested operation; and persisting the performed operation to the persistence data store in conformance with the determined persistence policy.