A comparative evaluation of techniques for N-way joins in wireless sensors networks

In wireless sensors networks, data are sensed and recorded as databases, and then acceded by relational queries. Joins are queries that are largely used. Joins collect data from several nodes’ table. These are operations that typically consume a lot of energy because they generate a large number of messages in the network. Researchers worked to decrease this consumed energy. Many strategies were proposed in this way, but most of them addressed only binary joins. N-way joins received few interests. N-way joins perform join operations between more than two tables. They cause greater energy consumption. Additionally, the number of execution order is very important; it grows exponentially with the number of considered tables.