Rails排序或訂購查詢很慢

Question

使用Rails 3.2，Ruby 1.9，will_paginate。我有10萬條記錄，並測試了以下疑問：

# 1000+ms to load 
@shops = Shop.where(:shop_type => @type).paginate(:include => :photos, :page => params[:page], :per_page => 25, :order => 'created_at DESC') 

# 1000+ms to load 
@shops = Shop.paginate(:include => :photos, :page => params[:page], :per_page => 25, :order => 'created_at DESC') 

# 1000+ms to load 
@shops = Shop.order('created_at DESC').limit(25) 

# 1+ms to load 
@shops = Shop.paginate(:include => :photos, :page => params[:page], :per_page => 25) 

我注意到order選項是慢得令人難以置信。測試結果顯示will_paginate不是問題。

我該如何更改它，以便可以加快order的查詢速度。

Answer 1

是的，嘗試在訂單欄上創建索引。它會加快速度。