InnoDB system tablespace contains the
InnoDB data dictionary (metadata for
InnoDB-related objects) and is the storage area
for the doublewrite buffer, the change buffer, and undo logs. The
system tablespace also contains table and index data for any
user-created tables that are created in the system tablespace. The
system tablespace is considered a shared tablespace since it is
shared by multiple tables.
The system tablespace is represented by one or more data files. By
default, one system data file, named
is created in the MySQL
data directory. The
size and number of system data files is controlled by the
For related information, see Section 14.6.1, “InnoDB Startup Configuration”, and Section 14.7.1, “Resizing the InnoDB System Tablespace”.