Question

使用Rails 4和Ruby 1.9.3。我在usuarios中有这个观点#show我正在渲染。控制器需要大量数据，但我已设法用eager_load减少查询，从300ms奇数减少到44ms。

我的问题是数据库调用没问题，但视图渲染时间接近30秒。

我已经确定我从控制器变量中获取了所有内容。

编辑：我已从控制器添加了查询本身

这是控制器方法，使用eager_loading

#app/controllers/usuarios_controller.rb

before_action :show_usuario, only: [:show]

def show
  if !@usuario.country_id.blank?
    @country = @usuario.country
  end
  respond_to do |format
    format.html
    format.js
  end
end

private
def show_usuario
  if usuario_signed_in?
    id = current_usuario.id
    @usuario = Usuario.eager_load(:profile).find(id)
  else
    @usuario = Usuario.eager_load(:profile, textos: [:likes, :text_medals, :tags]).find(params[:id])
  end
  @textos = Texto.eager_load(:likes, :text_medals, :tags).where(:usuario_id => @usuario.id).order("textos.created_at DESC").paginate(:page => params[:page]).per_page(6)
end

这是我的日志

Started GET "/" for 127.0.0.1 at 2014-03-25 12:55:39 +0100
  Usuario Load (1.4ms)  SELECT "usuarios".* FROM "usuarios" WHERE "usuarios"."id" = 12 ORDER BY "usuarios"."id" ASC LIMIT 1
Processing by UsuariosController#show as HTML
  Notification Load (1.2ms)  SELECT "notifications".* FROM "notifications" INNER JOIN "textos" ON "textos"."id" = "notifications"."text" WHERE (textos.usuario_id = 12 AND notifications.user_related != 12) ORDER BY "notifications"."id" DESC LIMIT 10
  SQL (1.2ms)  SELECT "usuarios"."id" AS t0_r0, "usuarios"."email" AS t0_r1, "usuarios"."encrypted_password" AS t0_r2, "usuarios"."reset_password_token" AS t0_r3, "usuarios"."reset_password_sent_at" AS t0_r4, "usuarios"."remember_created_at" AS t0_r5, "usuarios"."sign_in_count" AS t0_r6, "usuarios"."current_sign_in_at" AS t0_r7, "usuarios"."last_sign_in_at" AS t0_r8, "usuarios"."current_sign_in_ip" AS t0_r9, "usuarios"."last_sign_in_ip" AS t0_r10, "usuarios"."created_at" AS t0_r11, "usuarios"."updated_at" AS t0_r12, "usuarios"."nombre" AS t0_r13, "usuarios"."fecha_nac" AS t0_r14, "usuarios"."country_id" AS t0_r15, "usuarios"."is_admin" AS t0_r16, "usuarios"."publish_fbviews" AS t0_r17, "usuarios"."accept_terms" AS t0_r18, "profiles"."id" AS t1_r0, "profiles"."usuario_id" AS t1_r1, "profiles"."quote" AS t1_r2, "profiles"."quote_author" AS t1_r3, "profiles"."fb_account" AS t1_r4, "profiles"."twt_account" AS t1_r5, "profiles"."gpls_account" AS t1_r6, "profiles"."biografia" AS t1_r7, "profiles"."created_at" AS t1_r8, "profiles"."updated_at" AS t1_r9, "profiles"."hide_email" AS t1_r10, "profiles"."pic_file_name" AS t1_r11, "profiles"."pic_content_type" AS t1_r12, "profiles"."pic_file_size" AS t1_r13, "profiles"."pic_updated_at" AS t1_r14 FROM "usuarios" LEFT OUTER JOIN "profiles" ON "profiles"."usuario_id" = "usuarios"."id" WHERE "usuarios"."id" = $1 LIMIT 1  [["id", 12]]
USER CARGADO
  Country Load (0.7ms)  SELECT "countries".* FROM "countries" WHERE "countries"."id" = $1 LIMIT 1  [["id", 246]]
TEXTOS CARGADOS
  Rendered usuarios/_main_frame.html.erb (12082.9ms)
   (1.6ms)  SELECT COUNT(DISTINCT "textos"."id") FROM "textos" LEFT OUTER JOIN "likes" ON "likes"."texto_id" = "textos"."id" LEFT OUTER JOIN "text_medals_textos" ON "text_medals_textos"."texto_id" = "textos"."id" LEFT OUTER JOIN "text_medals" ON "text_medals"."id" = "text_medals_textos"."text_medal_id" LEFT OUTER JOIN "tags_textos" ON "tags_textos"."texto_id" = "textos"."id" LEFT OUTER JOIN "tags" ON "tags"."id" = "tags_textos"."tag_id" WHERE "textos"."usuario_id" = 12
  SQL (1.9ms)  SELECT DISTINCT "textos".id, textos.created_at AS alias_0 FROM "textos" LEFT OUTER JOIN "likes" ON "likes"."texto_id" = "textos"."id" LEFT OUTER JOIN "text_medals_textos" ON "text_medals_textos"."texto_id" = "textos"."id" LEFT OUTER JOIN "text_medals" ON "text_medals"."id" = "text_medals_textos"."text_medal_id" LEFT OUTER JOIN "tags_textos" ON "tags_textos"."texto_id" = "textos"."id" LEFT OUTER JOIN "tags" ON "tags"."id" = "tags_textos"."tag_id" WHERE "textos"."usuario_id" = 12 ORDER BY textos.created_at DESC LIMIT 6 OFFSET 0
  SQL (5.6ms)  SELECT "textos"."id" AS t0_r0, "textos"."usuario_id" AS t0_r1, "textos"."titulo" AS t0_r2, "textos"."contenido" AS t0_r3, "textos"."idioma" AS t0_r4, "textos"."created_at" AS t0_r5, "textos"."updated_at" AS t0_r6, "textos"."is_borrador" AS t0_r7, "textos"."is_on_contest" AS t0_r8, "textos"."portada_file_name" AS t0_r9, "textos"."portada_content_type" AS t0_r10, "textos"."portada_file_size" AS t0_r11, "textos"."portada_updated_at" AS t0_r12, "textos"."contest_id" AS t0_r13, "textos"."views" AS t0_r14, "textos"."has_draft" AS t0_r15, "textos"."license_type" AS t0_r16, "likes"."id" AS t1_r0, "likes"."usuario_id" AS t1_r1, "likes"."texto_id" AS t1_r2, "likes"."created_at" AS t1_r3, "likes"."updated_at" AS t1_r4, "text_medals"."id" AS t2_r0, "text_medals"."name" AS t2_r1, "text_medals"."slogan" AS t2_r2, "text_medals"."created_at" AS t2_r3, "text_medals"."updated_at" AS t2_r4, "text_medals"."image_file_name" AS t2_r5, "text_medals"."image_content_type" AS t2_r6, "text_medals"."image_file_size" AS t2_r7, "text_medals"."image_updated_at" AS t2_r8, "tags"."id" AS t3_r0, "tags"."nombre" AS t3_r1, "tags"."created_at" AS t3_r2, "tags"."updated_at" AS t3_r3 FROM "textos" LEFT OUTER JOIN "likes" ON "likes"."texto_id" = "textos"."id" LEFT OUTER JOIN "text_medals_textos" ON "text_medals_textos"."texto_id" = "textos"."id" LEFT OUTER JOIN "text_medals" ON "text_medals"."id" = "text_medals_textos"."text_medal_id" LEFT OUTER JOIN "tags_textos" ON "tags_textos"."texto_id" = "textos"."id" LEFT OUTER JOIN "tags" ON "tags"."id" = "tags_textos"."tag_id" WHERE "textos"."usuario_id" = 12 AND "textos"."id" IN (75, 74, 73, 70, 69, 68) ORDER BY textos.created_at DESC
  CACHE (0.0ms)  SELECT COUNT(DISTINCT "textos"."id") FROM "textos" LEFT OUTER JOIN "likes" ON "likes"."texto_id" = "textos"."id" LEFT OUTER JOIN "text_medals_textos" ON "text_medals_textos"."texto_id" = "textos"."id" LEFT OUTER JOIN "text_medals" ON "text_medals"."id" = "text_medals_textos"."text_medal_id" LEFT OUTER JOIN "tags_textos" ON "tags_textos"."texto_id" = "textos"."id" LEFT OUTER JOIN "tags" ON "tags"."id" = "tags_textos"."tag_id" WHERE "textos"."usuario_id" = 12
  Usuario Load (0.8ms)  SELECT "usuarios".* FROM "usuarios" WHERE "usuarios"."id" = $1 ORDER BY "usuarios"."id" ASC LIMIT 1  [["id", 12]]
  Profile Load (0.7ms)  SELECT "profiles".* FROM "profiles" WHERE "profiles"."usuario_id" = $1 ORDER BY "profiles"."id" ASC LIMIT 1  [["usuario_id", 12]]
  CACHE (0.1ms)  SELECT "usuarios".* FROM "usuarios" WHERE "usuarios"."id" = $1 ORDER BY "usuarios"."id" ASC LIMIT 1  [["id", 12]]
  CACHE (0.0ms)  SELECT "profiles".* FROM "profiles" WHERE "profiles"."usuario_id" = $1 ORDER BY "profiles"."id" ASC LIMIT 1  [["usuario_id", 12]]
  CACHE (0.1ms)  SELECT "usuarios".* FROM "usuarios" WHERE "usuarios"."id" = $1 ORDER BY "usuarios"."id" ASC LIMIT 1  [["id", 12]]
  CACHE (0.0ms)  SELECT "profiles".* FROM "profiles" WHERE "profiles"."usuario_id" = $1 ORDER BY "profiles"."id" ASC LIMIT 1  [["usuario_id", 12]]
  CACHE (0.1ms)  SELECT "usuarios".* FROM "usuarios" WHERE "usuarios"."id" = $1 ORDER BY "usuarios"."id" ASC LIMIT 1  [["id", 12]]
  CACHE (0.1ms)  SELECT "profiles".* FROM "profiles" WHERE "profiles"."usuario_id" = $1 ORDER BY "profiles"."id" ASC LIMIT 1  [["usuario_id", 12]]
  CACHE (0.0ms)  SELECT "usuarios".* FROM "usuarios" WHERE "usuarios"."id" = $1 ORDER BY "usuarios"."id" ASC LIMIT 1  [["id", 12]]
  CACHE (0.0ms)  SELECT "profiles".* FROM "profiles" WHERE "profiles"."usuario_id" = $1 ORDER BY "profiles"."id" ASC LIMIT 1  [["usuario_id", 12]]
  CACHE (0.1ms)  SELECT "usuarios".* FROM "usuarios" WHERE "usuarios"."id" = $1 ORDER BY "usuarios"."id" ASC LIMIT 1  [["id", 12]]
  CACHE (0.1ms)  SELECT "profiles".* FROM "profiles" WHERE "profiles"."usuario_id" = $1 ORDER BY "profiles"."id" ASC LIMIT 1  [["usuario_id", 12]]
  Rendered usuarios/_user_texts.html.erb (16760.5ms)
  Rendered usuarios/show.html.erb within layouts/application (28889.5ms)
Completed 200 OK in 29246ms (Views: 28898.8ms | ActiveRecord: 44.1ms)

正如您所看到的，视图需要很长时间才能呈现。这是“_user_texts”的部分内容。

<div class="ui grid">
  <% @textos.each do |texto| %>
  <div class="text row" text-pages="<%= @textos.total_pages%>">
    <div class="five wide column">
      <%= image_tag texto.portada.url(:medium), :class => "ui rounded medium left floated image text-cover" %>
    </div>
    <div class="eleven wide column">
      <div class="row">
        <h1 class="ui header">
          <%= link_to text_name(texto), usuario_texto_path(texto.usuario.id, texto.id), :class => "title-format"%>
          <div class="sub header subheader-format">
            escrito por <%= text_author_image texto %><%= text_author_name texto %> el <%= humanize_creation_date(texto.created_at) %>
          </div>
        </h1>
      </div>
      <div class="tag-list row">
        <div class="ui horizontal list">
          <% if not texto.tags.empty? %>
            <% texto.tags.each do |tag| %>
            <div class="tag item">
              <%= link_to tag.nombre, tag_path(tag.id), :class => "ui red large label" %>
            </div>
            <% end %>
          <% end %>
        </div>
      </div>
    </div>
  </div>
  <% end %>
</div>

<% if @textos.total_pages > @textos.current_page %>
<a id="more_texts" href="javascript:void(0)">
  <span class="vertical"></span><span>Ver más</span>
</a>
<% end %>

编辑：我正在使用分页。特别是will_paginate宝石。当我到达页面底部时，有一个用于获取更多结果的按钮。

有人可以告诉我如何让它更快？这让我疯了。谢谢！

Answer 1

我会对您的查询进行基准测试，对我来说似乎很重要。我认为重点应该是增强sql查询的性能。我不知道确切的内容，但我怀疑你在一个查询中需要这么多的智能。

例如，您可以在表中添加索引以提高性能。您还应该考虑您真正需要的属性，并使用select来定义它们。查询中较少的列会产生更快的结果。

最后，你正在做很多连接。看起来您几乎加入了所有模型。左连接非常慢，因为你查看了所有记录。如果你真的需要所有这些连接，那么如果你可以将其中一些左连接转换为内连接，那将会很棒。这将意味着大幅改进，因为您只需要检查相关记录。

Answer 2

在您在视图中调用.all或.each之前，即使将结果存储在控制器中的实例变量中，查询也不会实际运行。这实际上可能会使视图在数据库中实际存在时显得很慢。

尝试通过一些调用来对视图中的不同位置进行基准测试，以查看时间的使用位置。

http://api.rubyonrails.org/classes/ActiveSupport/Benchmarkable.html#method-i-benchmark

为了查看你的查询正在做什么并发现丢失的索引等，解释很方便。

http://guides.rubyonrails.org/active_record_querying.html#running-explain

Answer 3

解决。在Bullet宝石的帮助下，我重新制定了我渴望加载的方式。

事实证明，所做的一切在实践中都做得很好。问题是我的合作伙伴正在Dropbox中存储回形针的图像。 Dropbox很可能不是针对这种请求做出的，所以延迟就是因为这个原因。我们将改用亚马逊的S3。

对于未来的读者：请注意！并检查您存储图像的位置。

感谢大家！

为什么Rails如此缓慢地渲染视图？

3 个答案: