Querying non-conventional data is recognized as a major issue in new environments and applications such as those occurring in pervasive computing. A key issue is the abil- ity to query data, streams and services in a declarative way. Our overall objective is to make the development of perva- sive applications easier through database principles. In this paper, through the notion of virtual attributes and binding patterns, we define a data-centric view of pervasive environ- ments: the classical notion of database is extended to come up with a broader notion, defined as relational pervasive environment, integrating data, streams and active/passive services. Then, the so-called Serena algebra is proposed with operators to homogeneously handle data and services. Moreover, the notion of stream can also be smoothly inte- grated into this algebra. A prototype of Pervasive Environ- ment Management System has been implemented on which first experiments have been conducted to validate our ap- proach.