请问mysql innodb的非自增ID主键的效率？

Question

table：
news_id user_id

ALTER TABLE table DROP PRIMARY KEY, ADD PRIMARY KEY (`news_id`, `user_id`) USING BTREE;

这种情况下效率有多少影响？

Answer 1

Whether the primary key is auto-incremented does not affect the efficiency of the original primary key. Both auto-increment and primary key are independent functions.