爲什麼MongoDB緩慢插入數據？

Question

我試圖將解析的數據保存到MongoDB中。我想存儲每個引薦網址。目前需要花費很多時間才能插入到MongoDB中。

class ReferrerDocument 
    include MongoMapper::Document 
    key :website_url, String 
    key :referrer_url, String 
    key :full_referrer_url, String 
    key :count_of_appearance, Integer, :default => 1 
    key :current_time, Time 
    timestamps! 

    def self.save_referrer_info(website_url, referrer_url, full_referrer_url, current_time) 
     referrer_document = ReferrerDocument.last(:website_url => website_url, 
               :referrer_url => referrer_url, 
               :order => :id.asc) 
     if(referrer_document.nil?) 
     ReferrerDocument.create(:website_url => website_url, 
           :referrer_url => referrer_url, 
           :full_referrer_url => full_referrer_url, 
           :last_seen_at => 0, 
           :current_time => current_time) 
     else 
     count = referrer_document.count_of_appearance += 1 
     last_seen_at = referrer_document.current_time.utc 
     ReferrerDocument.create(:website_url => website_url, 
           :referrer_url => referrer_url, 
           :full_referrer_url => full_referrer_url, 
           :last_seen_at => last_seen_at, 
           :current_time => current_time, 
           :count_of_appearance => count) 
     end 
    end 
end 

Answer 1

你嘗試實際測量每個部分需要多長時間來執行呢？

從我看到的情況來看，唯一可能很慢的地方是ReferrerDocument.last調用。

您在此集合中擁有多少個文檔？你有支持指數嗎？ 什麼mongodb查詢ReferrerDocument.last翻譯（你可以在development.log中看到，我自己是mongoid用戶）？ 解釋這個查詢的計劃是什麼樣的？

要讓此查詢最有效率，您需要索引{website_url: 1, referrer_url: 1, _id: 1}