Mysql搜索LIKE需要太长时间

Question

我的数据库中的表“业务”有100 000条记录。 我的数据库的表“类别”有900条记录。 当我运行查询

    SELECT * FROM businesses b WHERE 
((b.name LIKE '%Fake%' 
AND (b.is_deleted = 0 || ISNULL(b.is_deleted))) 
OR EXISTS (SELECT * FROM  categories c 
WHERE c.`name` LIKE '%Fake%' 
AND c.is_deleted = 0 AND b.is_deleted = 0 
AND b.`categories_ids` LIKE CONCAT('%|', c.id, '|%'))) 
group by b.id ORDER BY b.`name` ASC LIMIT 0, 20;

返回结果只需0.06秒。 但是当我运行查询

时

SELECT * FROM businesses b WHERE 
((b.name LIKE '%Fake u%' 
AND (b.is_deleted = 0 || ISNULL(b.is_deleted))) 
OR EXISTS (SELECT * FROM  categories c 
WHERE c.`name` LIKE '%Fake u%' 
AND c.is_deleted = 0 AND b.is_deleted = 0 
AND b.`categories_ids` LIKE CONCAT('%|', c.id, '|%'))) 
group by b.id ORDER BY b.`name` ASC LIMIT 0, 20

它只是搜索字符串中的多个字符，但需要114才能返回结果。

为什么查询后花了太多时间???