| Popis: |
In considering the special characteristics of wireless sensor networks, extensions to SQL-based query language are needed. In this paper, two extensions to traditional SQL query language have been proposed, including timing and aggregations. In each extension, unique features of database for wireless sensor networks have been taken into consideration. For extension on timing, we mainly consider extending SQL with dynamic query support in a sliding window fashion. As to aggregation extension, both local and global aggregations are considered. Newly introduced clauses and semantic are described in detail with the help of examples. The proposals are general and capable of achieving various task goals with query based interaction in sensor networks. |
