我目前在一个活动网站上进行黑客攻击,过去从未遇到过优化查询/扩展我的数据库的问题,因为从来没有那么多数据,但现在数据库中有近一百万行,它需要大约 15,000 m/s呈现事件的提要,特别是非常慢的部分(在每个 _event.html.erb 内)是显示您当前关注的所有正在参加该事件的用户的位置。我已经寻找了很多提高性能的可能性,包括预加载、索引、内存缓存等……但是想知道如何重写它以更快地执行?谢谢!
_attending.html.erb
<% if user_signed_in? %>
<% @rsvp = Rsvp.where(:voter_id => current_user.following, :event_id => event.id, :status => 'going') %>
<% if @rsvp.count == 0 %>
<%= eventcount(event) %> going.
<% elsif @rsvp.count == 1 %>
<% if eventcount(event) - 1 == 0 %>
<% Rsvp.where(:voter_id => current_user.following, :event_id => event.id, :status => 'going')[0..0].each do |f| %>
<%= link_to User.find(f.voter_id).name, User.find(f.voter_id).slug %> is going.
<% end %>
<% else %>
<% Rsvp.where(:voter_id => current_user.following, :event_id => event.id, :status => 'going')[0..0].each do |f| %>
<%= link_to User.find(f.voter_id).name, User.find(f.voter_id).slug %> and <%= eventcount(event) - 1 %> going.
<% end %>
<% end %>
<% elsif @rsvp.count == 2 %>
<% if eventcount(event) - 2 == 0 %>
<% Rsvp.where(:voter_id => current_user.following, :event_id => event.id, :status => 'going')[0..0].each do |f| %>
<%= link_to User.find(f.voter_id).name, User.find(f.voter_id).slug %> and
<% end %>
<% Rsvp.where(:voter_id => current_user.following, :event_id => event.id, :status => 'going')[1..1].each do |f| %>
<%= link_to User.find(f.voter_id).name, User.find(f.voter_id).slug %> are going.
<% end %>
<% else %>
<% Rsvp.where(:voter_id => current_user.following, :event_id => event.id, :status => 'going')[0..0].each do |f| %>
<%= link_to User.find(f.voter_id).name, User.find(f.voter_id).slug %>,
<% end %>
<% Rsvp.where(:voter_id => current_user.following, :event_id => event.id, :status => 'going')[1..1].each do |f| %>
<%= link_to User.find(f.voter_id).name, User.find(f.voter_id).slug %> and <%= eventcount(event) - 2 %> going.
<% end %>
<% end %>
<% elsif @rsvp.count == 3 %>
<% if eventcount(event) - 3 == 0 %>
<% Rsvp.where(:voter_id => current_user.following, :event_id => event.id, :status => 'going')[0..0].each do |f| %>
<%= link_to User.find(f.voter_id).name, User.find(f.voter_id).slug %>,
<% end %>
<% Rsvp.where(:voter_id => current_user.following, :event_id => event.id, :status => 'going')[1..1].each do |f| %>
<%= link_to User.find(f.voter_id).name, User.find(f.voter_id).slug %>, and
<% end %>
<% Rsvp.where(:voter_id => current_user.following, :event_id => event.id, :status => 'going')[2..2].each do |f| %>
<%= link_to User.find(f.voter_id).name, User.find(f.voter_id).slug %> are going.
<% end %>
<% else %>
<% Rsvp.where(:voter_id => current_user.following, :event_id => event.id, :status => 'going')[0..0].each do |f| %>
<%= link_to User.find(f.voter_id).name, User.find(f.voter_id).slug %>,
<% end %>
<% Rsvp.where(:voter_id => current_user.following, :event_id => event.id, :status => 'going')[1..1].each do |f| %>
<%= link_to User.find(f.voter_id).name, User.find(f.voter_id).slug %>,
<% end %>
<% Rsvp.where(:voter_id => current_user.following, :event_id => event.id, :status => 'going')[2..2].each do |f| %>
<%= link_to User.find(f.voter_id).name, User.find(f.voter_id).slug %> and <%= eventcount(event) - 3 %> are going.
<% end %>
<% end %>
<% end %>
<% else %>
<%= eventcount(event) %> going.
<% end %>
RSVP 的架构
create_table "rsvps", :force => true do |t|
t.string "status"
t.integer "event_id"
t.integer "voter_id"
t.string "voter_name"
t.string "voter_type"
t.timestamp "created_at", :null => false
t.timestamp "updated_at", :null => false
end
add_index "rsvps", ["voter_id", "voter_type", "event_id"], :name => "fk_one_rsvp_per_user_per_entity", :unique => true
add_index "rsvps", ["voter_id", "voter_type"], :name => "index_rsvps_on_voter_id_and_voter_type"
关系模式
create_table "relationships", :force => true do |t|
t.integer "follower_id"
t.integer "followed_id"
t.timestamp "created_at", :null => false
t.timestamp "updated_at", :null => false
end
add_index "relationships", ["followed_id"], :name => "index_relationships_on_followed_id"
add_index "relationships", ["follower_id"], :name => "index_relationships_on_follower_id"
用户模型的相关部分
has_many :relationships, :foreign_key => "follower_id",
:dependent => :destroy
has_many :following, :through => :relationships, :source => :followed
has_many :reverse_relationships, :foreign_key => "followed_id",
:class_name => "Relationship",
:dependent => :destroy
has_many :followers, :through => :reverse_relationships, :source => :follower