MariaDB [information_schema]> create table test.t( i int);

Query OK, 0 rows affected (0.007 sec)

MariaDB [information_schema]> create table test.t1( i int primary key);

Query OK, 0 rows affected (0.005 sec)

MariaDB [information_schema]> select * from INNODB_SYS_TABLES;

+----------+----------------------------+------+--------+-------+------------+---------------+------------+

| TABLE_ID | NAME                       | FLAG | N_COLS | SPACE | ROW_FORMAT | ZIP_PAGE_SIZE | SPACE_TYPE |

+----------+----------------------------+------+--------+-------+------------+---------------+------------+

|       20 | test/t                     |   33 |      4 |     5 | Dynamic    |             0 | Single     |

|       21 | test/t1                    |   33 |      4 |     6 | Dynamic    |             0 | Single     |