Secure query processing and optimization in cloud environment: a review

Cloud computing is trusted and used by millions of users around the world. Therefore, it becomes essential to offer trusted and efficient services to its users. Query processing and query optimization are the major components to provide optimal query plans for users through different steps. So far, the mathematical evaluation including algebraic transformation and selectivity estimation models are performed to improve the security while optimization and processing of query. Meanwhile, they have several equivalence rules to have various logical form. That problem was stated by single query processing at a time, but they are not efficient for dynamic operation of cloud since they are slower. Hence, this paper presents a review of improvement made to the processing and optimization of queries with the security enhancement in the past 8 years neglecting the tedious mathematical procedures. Along with the query processing techniques, the quantitative analysis of those techniques is provided in the paper based on deterministic and non-deterministic query processing techniques. As a result, it is found that when utilizing multiple query processing techniques, the host system may get loaded and struck, while the adaptive model works better by providing the process to host system based on its processing capability.