Abstract:The concurrency control algorithm is a key component to guarantee the correctness and efficiency of executing transactions. Thus far, substantial effort has been devoted to proposing new concurrency controls algorithms in both database industry and academia. This study abstracts a common paradigm of the state-of-the-art and summarizes the core idea of concurrency control algorithms as “ordering-and-verifying”. Then, the existing concurrency control algorithms are re-presented following the ordering-and-verifying paradigm. Based on extensive experiments under an open-source memory-based distributed transaction testbed called 3TS, it is systematically demonstrated the advantages and disadvantages of the mainstream state-of-the-art concurrency control algorithms. Finally, the preferable application scenario is summarized for each algorithm and some valuable references are provided for the follow-up research of concurrency control algorithms used in in-memory databases.