通过实例认识MySQL中前缀索引的用法

root@test 07:57:52>alter table article drop index ind_article_url;
Query OK, 144384 rows affected (16.29 sec)
Records: 144384 Duplicates: 0 Warnings: 0
root@test 07:58:40>alter table article add index ind_article_url(url);
Query OK, 144384 rows affected, 1 warning (19.52 sec)
Records: 144384 Duplicates: 0 Warnings: 0
root@test 07:59:23>show warnings;
+———+——+———————————————————+
| Level  | Code | Message                         |
+———+——+———————————————————+
| Warning | 1071 | Specified key was too long; max key length is 767 bytes |
+———+——+———————————————————+
1 row in set (0.00 sec)

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