Database Optimization in the Cloud: Where Costs, Partial Results, and Consumer Choice Meet.

Database services in the cloud (DBaaS) allow users to convert the fixed costs of deploying and maintaining a database system to variable costs that are incurred in a pay-as-you-go manner. Considerable research focus has been given to the cost of the elasticity (of performance) and reliability of a DBaaS. This is because in the cloud, users are able to modulate these characteristics of a DBaaS by paying more or less to the provider. However, the one invariant has always been that the user will receive a complete and correct result. In this paper we consider another possibility; that users may be willing to accept different quality results from a DBaaS that aren’t complete and correct if the price is right. Recently, there has been research classifying “partial results” produced using incomplete input (due to failures) while processing a query. These classifications provide a broad and general way to understand a partial result using semantic guarantees that can be made about the result. In this paper, we consider a database system in the cloud that allows users to control the cost of a query by defining the sorts of partial results that are acceptable.