SQL 查询优化 - 来自另一个表的多行

Question

I have my tables like this (currently)

CREATE TABLE `users` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `name` varchar(64) DEFAULT NULL,
  PRIMARY KEY (`id`)
);

CREATE TABLE `user_opts` (
  `user_id` bigint(20) NOT NULL,
  `opt1` varchar(64) DEFAULT NULL,
  `opt2` TINYINT(4) DEFAULT NULL,
  `opt3` varchar(64) DEFAULT NULL,
  KEY `user_id_idx` (`user_id`)
);

I want to be able to do queries like this:

SELECT DISTINCT name
FROM users
WHERE 
    id = 1 AND (
        EXISTS ( SELECT 1 FROM user_opts WHERE user_opts.user_id = users.id AND user_opts.opt1 = 'a' AND user_opts.opt3 = 'c') OR
        EXISTS ( SELECT 1 FROM user_opts WHERE user_opts.user_id = users.id AND user_opts.opt1 = 'b' AND user_opts.opt2 = 1)
    );

and this:

SELECT DISTINCT name
FROM users
WHERE 
    id = 1 AND (
        EXISTS ( SELECT 1 FROM user_opts WHERE user_opts.user_id = users.id AND user_opts.opt1 = 'a' AND user_opts.opt3 = 'e') AND
        EXISTS ( SELECT 1 FROM user_opts WHERE user_opts.user_id = users.id AND user_opts.opt1 = 'b' AND user_opts.opt2 = 1)
    );

The obvious problem I'm starting to have is that the more users the queries goes slower and slower. I know I could refactor the first type of the queries (using OR ) by JOINing the table, but the JOIN itself would be slow since I can't have a PK on the user_opts table.

How could I restructure my data (and the queries) so I can do efficient/fast searches? Preferably, if possible, I would like to keep the same queries for both AND and OR types, just switching the condition between the two.

DB Fiddle url

Thanks!

Answer 1

You can use aggregation:

select user_id
from user_opts uo
where opt3 = 'c' or opt2 = 1
group by user_id
having sum(opt3 = 'c') >= 1 and
       sum(opt2 = 1) >= 1;

This handles the case when the two options are set on the same row in user_opts .

Answer 2

Adding these two indexes would speed up the EXISTS :

INDEX(user_id, opt1, opt3)
INDEX(user_id, opt1, opt2)

Your schema is a variant on EAV, which is notoriously inefficient and clumsy. Is there a good reason not to have opt2 and opt3 in users ?