表格有200.000+条记录需要4秒钟选择

Question

我有一个表following，其中一个用户可以关注另一个用户。 此表有200.000+条记录。我的选择需要一段时间。

where (p.user in (select following from following where user =1 and block=0 and feed=0) or p.user=1) and p.delete='0'

我有where来users user=1跟随`following` ( `id` int(11) UNSIGNED NOT NULL AUTO_INCREMENT, `user` INT(11) UNSIGNED NOT NULL REFERENCES cadastro (`id`), `following` INT(11) UNSIGNED NOT NULL REFERENCES cadastro (`id`), `block` tinyint(1) NOT NULL DEFAULT 0, `feed` tinyint(1) NOT NULL DEFAULT 0, `data` datetime NOT NULL, PRIMARY KEY (`id`), UNIQUE KEY (`user`, `following`) ) 。这是需要更长时间的合作伙伴。

我的下表：

select c.nome, p.foto, c.user, p.user, p.id, p.data, p.titulo, p.youtube, pp.foto, count(DISTINCT likes.user) as likes_count, count(distinct comentarios.id) as comentarios_count, count(DISTINCT l2.user) as count2 

from posts p 

join cadastro c on p.user=c.id 
left join profile_picture pp on p.user = pp.user
left join likes on likes.post = p.id
left join comentarios on comentarios.foto = p.id and comentarios.delete = 0  
left join likes l2 on l2.post = p.id and l2.user = ?

where (p.user in (select following from following where user =? and block=0) or p.user=?) and p.delete='0'

group by p.id
order by p.id desc limit ?

如何更快地获得关注并改进此表的任何想法？任何指数或任何想法？

我的完整sql：

  KEY `share` (post_share, `delete`),
  PRIMARY KEY (`id`)

帖子：

    writer = pd.ExcelWriter(xlPath, engine='openpyxl')
    df.to_excel(writer)
    writer.close()

感谢。

Answer 1

我不确定你是否只想提起following.block=0。在following表上，您看起来应该有(user, following, block)的索引，这将使其成为仅索引扫描。

摆脱嵌套查询很重要。

这是一个猜测，但我相信你正在寻找以下内容：

select c.nome,
 p.foto,
 c.user,
 p.user,
 p.id,
 p.data,
 p.titulo,
 p.youtube,
 pp.foto,
 count(DISTINCT likes.user) as likes_count,
 count(distinct comentarios.id) as comentarios_count, 
 count(DISTINCT l2.user) as count2 

from posts p 

    join cadastro c on p.user=c.id 
    left join profile_picture pp on p.user = pp.user
    left join likes on likes.post = p.id
    left join comentarios on comentarios.foto = p.id and comentarios.delete = 0  
    left join likes l2 on l2.post = p.id and l2.user = ?

    left join following f on f.user = p.user

where 
(p.user = ? and p.delete = '0')
or 
(f.user = ? and f.block=0)

group by p.id
order by p.id desc limit ?