Comment 1 for bug 1733006

Thank you for the reasonable feature request.

However you can already know how many times index was used if use Performance Schema:

mysql> select object_schema, object_name, index_name, count_fetch, count_insert, count_delete, count_update from performance_schema.table_io_waits_summary_by_index_usage where object_schema='test';
+---------------+-------------+------------+-------------+--------------+--------------+--------------+
| object_schema | object_name | index_name | count_fetch | count_insert | count_delete | count_update |
+---------------+-------------+------------+-------------+--------------+--------------+--------------+
| test | t1 | i_idx | 1 | 0 | 0 | 0 |
| test | t1 | j_idx | 0 | 0 | 0 | 0 |
| test | t1 | k_idx | 0 | 0 | 0 | 0 |
| test | t1 | NULL | 3 | 3 | 0 | 0 |
+---------------+-------------+------------+-------------+--------------+--------------+--------------+
4 rows in set (0,01 sec)

It won't count ignored indexes.