gistfile1.txt

mysql56> SELECT table_name, index_name, sum(number_records) FROM information_schema.innodb_buffer_page WHERE table_name = '`d1`.`t1`' GROUP BY 1, 2;
Empty set (0.04 sec)

mysql56> SELECT 1 FROM d1.t1 FORCE INDEX(val);
..
10000 rows in set (0.01 sec)

mysql56> SELECT table_name, index_name, sum(number_records) FROM information_schema.innodb_buffer_page WHERE table_name = '`d1`.`t1`' GROUP BY 1, 2;
+------------+------------+---------------------+
| table_name | index_name | sum(number_records) |
+------------+------------+---------------------+
| `d1`.`t1`  | num        |                 127 |
| `d1`.`t1`  | val        |               10030 |
+------------+------------+---------------------+