Two-Phase Locking (Deadlock Detection)
(1) Global wait-for-graphs are created to detect deadlocks. (2) The timer is applied to count how long a transaction has been started. If a transaction is not finished within a given time period, the timer will indicate a potential deadlock.
3-level storage strategy is used to save storage resources and reduce query latency. According to the 3-level storage strategy, all data can be classified into Standard Storage (hot data), Infrequent access Storage (warm data), and Archive (cold data). Automatic conversion is trigger between different storage levels under different lifecycles. Standard storage is stored in three copies on SSD and Infrequent access Storage is stored in 2 copies on SATA. Archive is stored in 1.3 copies on SATA.