因为工作的需要 需要学习Activiti
学习资料：
https://www.activiti.org/userguide/
Database table names explained
The database names of Activiti all start with ACT_. The second part is a two-character identification of the use case of the table. This use case will also roughly match the service API.
- ACT_RE_*: RE stands for repository. Tables with this prefix contain static information such as process definitions and process resources (images, rules, etc.).
- ACT_RU_*: RU stands for runtime. These are the runtime tables that contain the runtime data of process instances, user tasks, variables, jobs, etc. Activiti only stores the runtime data during process instance execution, and removes the records when a process instance ends. This keeps the runtime tables small and fast.
- ACT_ID_*: ID stands for identity. These tables contain identity information, such as users, groups, etc.
- ACT_HI_*: HI stands for history. These are the tables that contain historic data, such as past process instances, variables, tasks, etc.
- ACT_GE_*: general data, which is used in various use cases.