【MySQL 5.7 Reference Manual】15.4.6 InnoDB Data Dictionary（InnoDB数据字典）

15.4.6 InnoDB Data Dictionary（InnoDB数据字典）

The InnoDB data dictionary is comprised of internal system tables that contain metadata used to keep track of objects such as tables, indexes, and table columns. The metadata is physically located in the InnoDB system tablespace. For historical reasons, data dictionary metadata overlaps to some degree with information stored in InnoDB table metadata files (.frm files).

InnoDB数据字典由内部系统表组成，它包含了用于维持对象（比如表、索引和表列）记录的元数据。元数据的物理位置位于InnoDB系统表空间。由于历史原因，数据字典元数据和存储在InnoDB表元数据文件中的信息有一定程度的重叠。