| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
|---|---|---|---|---|---|---|---|---|---|
| 1 | PRIMARY | c | ALL | TABLE_SCHEMA, TABLE_NAME | Using where; Open_frm_only; Scanned 0 databases; Using temporary; Using filesort | ||||
| 1 | PRIMARY | t | ALL | TABLE_SCHEMA | Using where; Open_frm_only; Scanned 1 database; Using join buffer (flat, BNL join) | ||||
| 2 | DEPENDENT SUBQUERY | i_c | ALL | CONSTRAINT_SCHEMA | Using where; Open_full_table; Scanned 1 database |