Yes and no. q supports SQL out of the box. In many cases, you will see an improvement in performance compared to a similar traditional RDBMS. However, q does not optimize your queries for you, so some queries may actually take more time.
James Gosling stated that he purposely made Java syntax C-like to facilitate the adoption of the JVM platform. q’s query language was similarly designed to resemble SQL. Begin with what you know, and incrementally refine your queries using q-specific features to get the best performance possible.