MySQL - 索引innodb外键(MySQL - indexing innodb foreign keys)

 InnoDB中索引外键的性能有所改善吗？ 据我所知，InnoDB会自动为外键创建索引。 
 
 这是给我创建表的查询。 
 
DROP TABLE IF EXISTS `assignments`;

CREATE TABLE `assignments`
(
    `id` INTEGER NOT NULL AUTO_INCREMENT,
    `user` INTEGER NOT NULL,
    `job` INTEGER NOT NULL,
    `created_at` DATETIME,
    `updated_at` DATETIME,
    PRIMARY KEY (`id`),
    INDEX `job_fk1` (`user`),
    INDEX `job_fk2` (`job`),
    CONSTRAINT `job_fk1`
        FOREIGN KEY (`user`)
        REFERENCES `users` (`id`),
    CONSTRAINT `job_fk2`
        FOREIGN KEY (`job`)
        REFERENCES `jobs` (`id`)
) ENGINE=InnoDB;
 
 在那里，他创建了名为job_fk1和job_fk2的外键。 他使用这些外键的名称作为索引的名称。 

Is there an improvement in performance in indexing foreign keys in InnoDB? As far as I have read, InnoDB automatically creates an index for the foreign key.
 
Here is the query given to me for creating the table.
 
DROP TABLE IF EXISTS `assignments`;

CREATE TABLE `assignments`
(
    `id` INTEGER NOT NULL AUTO_INCREMENT,
    `user` INTEGER NOT NULL,
    `job` INTEGER NOT NULL,
    `created_at` DATETIME,
    `updated_at` DATETIME,
    PRIMARY KEY (`id`),
    INDEX `job_fk1` (`user`),
    INDEX `job_fk2` (`job`),
    CONSTRAINT `job_fk1`
        FOREIGN KEY (`user`)
        REFERENCES `users` (`id`),
    CONSTRAINT `job_fk2`
        FOREIGN KEY (`job`)
        REFERENCES `jobs` (`id`)
) ENGINE=InnoDB;
 
In there, he created foreign keys named job_fk1 and job_fk2. He used the names of these foreign keys as the name of the index.

原文：https://stackoverflow.com/questions/28977982