如何对mongodb / mongoid脚本进行基准测试，以比较两种不同的查询技术
您是否有关于如何在两种不同的mongoid / mongodb查询实现上测试性能的建议？
要比较的实现与先前的“问答”相关，但为了简洁起见，我将再次在此处报告：
第一个代码：
Competitor = Struct.new(:html_url, :description, :user) competitors = [] User.all.map do |user| user.watchlists.all.map do |wl| if wl.tags_array == ["ruby", "web", "framework"] competitors << Competitor.new(wl.html_url, wl.description, wl.user.nickname) end end end 与第二代码：
Competitor = Struct.new(:html_url, :description, :user) competitors = [] User.where('watchlists.tags_array' => %w[ruby web framework]).only(:nickname, :watchlists).each do |u| u.watchlists.where(:tags_array => %w[ruby web framework]).each do |wl| competitors << Competitor.new(wl.html_url, wl.description, u.nickname) end end
而对于完整性，
下划线数据模型是：
class User include Mongoid::Document field :nickname embeds_many :watchlists end class Watchlist include Mongoid::Document field :html_url field :description field :tags_array, type: Array embedded_in :user end
目前对这两个代码进行基准测试和比较表现的方式是什么？
到现在为止，我发现了这种方式，但如果你知道更好的事情，请回答……
第一个代码：
1.9.2p290 :038 > Competitor = Struct.new(:html_url, :description, :user) 1.9.2p290 :039 > time = Benchmark.measure do 1.9.2p290 :040 > competitors = [] 1.9.2p290 :041?> 1.9.2p290 :042 > User.all.map do |user| 1.9.2p290 :043 > user.watchlists.all.map do |wl| 1.9.2p290 :044 > if wl.tags_array == ["ruby", "web", "framework"] 1.9.2p290 :045?> competitors << Competitor.new(wl.html_url, wl.description, wl.user.nickname) 1.9.2p290 :046?> end 1.9.2p290 :047?> end 1.9.2p290 :048?> end 1.9.2p290 :049?> end MONGODB (34ms) heroku_app1707530['users'].find({}) MONGODB [DEBUG] cursor.refresh() for cursor 2492208785546818168 MONGODB [DEBUG] cursor.refresh() for cursor 2492208785546818168 => 1.390000 0.010000 1.400000 ( 1.400842) 1.9.2p290 :050 >
与第二代码：
1.9.2p290 :049 > Competitor = Struct.new(:html_url, :description, :user) 1.9.2p290 :050 > time = Benchmark.measure do 1.9.2p290 :051 > competitors = [] 1.9.2p290 :052?> 1.9.2p290 :053 > User.where('watchlists.tags_array' => %w[ruby web framework]).only(:nickname, :watchlists).each do |u| 1.9.2p290 :054 > u.watchlists.where(:tags_array => %w[ruby web framework]).each do |wl| 1.9.2p290 :055 > competitors << Competitor.new(wl.html_url, wl.description, u.nickname) 1.9.2p290 :056?> end 1.9.2p290 :057?> end 1.9.2p290 :058?> end MONGODB (185ms) heroku_app1707530['users'].find({"watchlists.tags_array"=>["ruby", "web", "framework"]}, {:_type=>1, :nickname=>1, :watchlists=>1}) MONGODB [DEBUG] cursor.refresh() for cursor 2195378613558492020 => 0.440000 0.000000 0.440000 ( 0.456714) 1.9.2p290 :059 >
但更好的是：
第一个代码：
1.9.2p290 :157 > Competitor = Struct.new(:html_url, :description, :user) 1.9.2p290 :158 > competitors = [] => [] 1.9.2p290 :159 > Benchmark.bm(10) do |x| 1.9.2p290 :160 > x.report("first:") do 1.9.2p290 :161 > User.all.map do |user| 1.9.2p290 :162 > user.watchlists.all.map do |wl| 1.9.2p290 :163 > if wl.tags_array == ["ruby", "web", "framework"] 1.9.2p290 :164?> competitors << Competitor.new(wl.html_url, wl.description, wl.user.nickname) 1.9.2p290 :165?> end 1.9.2p290 :166?> end 1.9.2p290 :167?> end 1.9.2p290 :168?> end 1.9.2p290 :169?> x.report("second:") do 1.9.2p290 :170 > User.all.map do |user| 1.9.2p290 :171 > user.watchlists.all.map do |wl| 1.9.2p290 :172 > if wl.tags_array == ["ruby", "web", "framework"] 1.9.2p290 :173?> competitors << Competitor.new(wl.html_url, wl.description, wl.user.nickname) 1.9.2p290 :174?> end 1.9.2p290 :175?> end 1.9.2p290 :176?> end 1.9.2p290 :177?> end 1.9.2p290 :178?> x.report("third:") do 1.9.2p290 :179 > User.all.map do |user| 1.9.2p290 :180 > user.watchlists.all.map do |wl| 1.9.2p290 :181 > if wl.tags_array == ["ruby", "web", "framework"] 1.9.2p290 :182?> competitors << Competitor.new(wl.html_url, wl.description, wl.user.nickname) 1.9.2p290 :183?> end 1.9.2p290 :184?> end 1.9.2p290 :185?> end 1.9.2p290 :186?> end 1.9.2p290 :187?> end user system total real first: MONGODB (30ms) heroku_app1707530['users'].find({}) MONGODB [DEBUG] cursor.refresh() for cursor 6320857008182747446 MONGODB [DEBUG] cursor.refresh() for cursor 6320857008182747446 1.460000 0.010000 1.470000 ( 1.475545) second: MONGODB (24ms) heroku_app1707530['users'].find({}) MONGODB [DEBUG] cursor.refresh() for cursor 8580701579081246457 MONGODB [DEBUG] cursor.refresh() for cursor 8580701579081246457 1.470000 0.010000 1.480000 ( 1.494812) third: MONGODB (24ms) heroku_app1707530['users'].find({}) MONGODB [DEBUG] cursor.refresh() for cursor 6472818135140756688 MONGODB [DEBUG] cursor.refresh() for cursor 6472818135140756688 1.490000 0.010000 1.500000 ( 1.505000) => true 1.9.2p290 :188 >
与第二代码：
1.9.2p290 :065 > Competitor = Struct.new(:html_url, :description, :user) 1.9.2p290 :066 > competitors = [] => [] 1.9.2p290 :067 > Benchmark.bm(10) do |x| 1.9.2p290 :068 > x.report("first:") {User.where('watchlists.tags_array' => %w[ruby web framework]).only(:nickname, :watchlists).each{|u|u.watchlists.where(:tags_array => %w[ruby web framework]).each{|wl|competitors << Competitor.new(wl.html_url, wl.description, u.nickname)}}} 1.9.2p290 :069?> x.report("second:") {User.where('watchlists.tags_array' => %w[ruby web framework]).only(:nickname, :watchlists).each{|u|u.watchlists.where(:tags_array => %w[ruby web framework]).each{|wl|competitors << Competitor.new(wl.html_url, wl.description, u.nickname)}}} 1.9.2p290 :070?> x.report("third:") {User.where('watchlists.tags_array' => %w[ruby web framework]).only(:nickname, :watchlists).each{|u|u.watchlists.where(:tags_array => %w[ruby web framework]).each{|wl|competitors << Competitor.new(wl.html_url, wl.description, u.nickname)}}} 1.9.2p290 :071?> end user system total real first: MONGODB (163ms) heroku_app1707530['users'].find({"watchlists.tags_array"=>["ruby", "web", "framework"]}, {:_type=>1, :nickname=>1, :watchlists=>1}) MONGODB [DEBUG] cursor.refresh() for cursor 7239021952645827000 0.330000 0.000000 0.330000 ( 0.380199) second: MONGODB (164ms) heroku_app1707530['users'].find({"watchlists.tags_array"=>["ruby", "web", "framework"]}, {:_type=>1, :nickname=>1, :watchlists=>1}) MONGODB [DEBUG] cursor.refresh() for cursor 4816095738351422260 0.320000 0.010000 0.330000 ( 0.381196) third: MONGODB (125ms) heroku_app1707530['users'].find({"watchlists.tags_array"=>["ruby", "web", "framework"]}, {:_type=>1, :nickname=>1, :watchlists=>1}) MONGODB [DEBUG] cursor.refresh() for cursor 5014359782446173361 0.390000 0.010000 0.400000 ( 0.397241) => true 1.9.2p290 :072 >
然后第二个代码结果真的更快，消耗更少的CPU …，由于“第二代码”的 rubish