“…[5] used tree kernels to model SQL statements and detect intrusions; although using tree kernels enabled them to exploit the structure of the SQL syntax and proved that this, indeed, has a good effect on performance, the method introduced a huge computational overhead, making anomaly detection drastically slow. We have stressed the importance of timely detection in a previous work [27] and have concluded on candidate algorithms that perform well with large query data sets. Therefore, in this paper, we show the…”