数据字典模式将字典数据存储在事务性（InnoDB）表中。数据字典表位于 mysql 数据库中，与非数据字典系统表一起。The data dictionary schema stores dictionary data in transactional (InnoDB) tables. Data dictionary tables are located in the mysql database together with non-data dictionary system tables.

数据字典表在一个名为 mysql.ibd 的单一 InnoDB 表空间中创建，该表空间位于 MySQL 数据目录中。mysql.ibd 表空间文件必须位于 MySQL 数据目录中，其名称不能修改，也不能被其他表空间使用。Data dictionary tables are created in a single InnoDB tablespace named mysql.ibd, which resides in the MySQL data directory. The mysql.ibd tablespace file must reside in the MySQL data directory and its name cannot be modified or used by another tablespace.

字典数据受与存储在 InnoDB 表中的用户数据相同的提交、回滚和崩溃恢复功能保护。Dictionary data is protected by the same commit, rollback, and crash-recovery capabilities that protect user data that is stored in InnoDB tables.