⟩ How To Drop an Existing Index in MySQL?
If you don't need an existing index any more, you should delete it with the "DROP INDEX indexName ON tableName" statement. Here is an example SQL script:
mysql> DROP INDEX tip_subject ON tip;
Query OK, 0 rows affected (0.13 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> SHOW INDEX FROM TIP;+------------+-------------+--------------+-------------+...
| Non_unique | Key_name | Seq_in_index | Column_name |...
+------------+-------------+--------------+-------------+...
| 0 | PRIMARY | 1 | id |...
+------------+-------------+--------------+-------------+...
1 row in set (0.00 sec)
