With the trend of cloud computing, data and computing are moved away from desktop and are instead provided as a service from the cloud. Data-as-a-service enables access to a wealth of data across distributed and heterogeneous data sources in the cloud. We designed and developed DObjects, a general-purpose P2P-based query and data operations infrastructure that can be deployed in the cloud. This paper presents the details of the dynamic query execution engine within our data query infrastructure that dynamically adapts to network and node conditions. The query processing is capable of fully benefiting from all the distributed resources to minimize the query response time and maximize system throughput. We present a set of experiments using both simulations and real implementation and deployment.