MongoDB 2.6支持update命令，请参见http://docs.mongodb.org/manual/reference/command/update/
Mongoid.default_session使您在MongoDB数据库级别上获得了对command方法的相应访问。
以下示例显示如何构造和发出批量更新命令以回答您的问题。
输出显示了10个列表，
单个与批量更新运行时间的比较，
Product集合的包含更新后库存计数的转储，
以及批量更新命令的结构。
即使在这个简单的演示中，批量更新与单个更新相比性能有了显着提高。
Ruby 'mongo' 1.x驱动程序支持用于批量写入的流畅API，
新的Ruby 'mongo' 2.0驱动程序也将支持此功能，最终将进入Mongoid。
Mongoid v3+目前使用的是Moped驱动程序，它没有用于批量写入的流畅API。
但正如本文所示，
通过Session#command方法，在Mongoid/Moped中构建并直接发出批量写（批量更新）命令是相当简单的。
希望这可以帮助您。
app/models/product.rb
class Product
include Mongoid::Document
field :name, type: String
field :stock, type: Integer, default: 0
has_and_belongs_to_many :lists, index: true
end
应用程序/模型/列表.rb
class List
include Mongoid::Document
field :name, type: String
has_and_belongs_to_many :products
end
测试/单元/product_test.rb
require 'test_helper'
require 'benchmark'
require 'pp'
class ProductTest < ActiveSupport::TestCase
def setup
@session = Mongoid.default_session
@session.drop
end
test '0. mongoid version' do
puts "\nMongoid::VERSION:#{Mongoid::VERSION}\nMoped::VERSION:#{Moped::VERSION}"
end
def individual_updates(list_ids, repetitions)
repetitions.times do
list_ids.each_with_index do |list_id, index|
Product.where(:list_ids => list_id).update_all({'$inc' => {'stock' => index}})
end
end
end
def bulk_command(list_ids, repetitions)
updates = []
repetitions.times do
list_ids.each_with_index do |list_id, index|
updates << {'q' => {'list_ids' => list_id}, 'u' => {'$inc' => {'stock' => index}}, 'multi' => true}
end
end
{ update: Product.collection_name.to_s, updates: updates, ordered: false }
end
def bulk_updates(list_ids, repetitions)
@session.command(bulk_command(list_ids, repetitions))
end
test 'x' do
puts
[
['ASUS MeMO Pad FHD 10', ['ASUS', 'tablet', 'Android']],
['Apple iPad Air Wi-Fi + Cellular 128GB - Silver', ['Apple', 'tablet', 'iOS']],
['Apple iPad mini with Retina display Wi-Fi + Cellular 128GB - Silver', ['Apple', 'tablet', 'iOS']],
['Apple iPhone 5c 32GB Green', ['Apple', 'phone', 'iOS']],
['Apple iPhone 5s 64GB Space Gray', ['Apple', 'phone', 'iOS']],
['LG G Pad 8.3 Tablet', ['LG', 'tablet', 'Android']],
['LG Google Nexus 5 White', ['LG', 'phone', 'Android']],
['Microsoft Surface 7ZR-00001', ['Microsoft', 'tablet', 'Windows 8 RT']],
['Samsung Galaxy S4 I9500', ['Samsung', 'phone', 'Android']],
['Samsung Galaxy Tab S 8.4', ['Samsung', 'tablet', 'Android']]
] .each do |product_name, list_names|
product = Product.create(name: product_name)
list_names.each do |list_name|
list = List.where(name: list_name).first_or_create
list.products << product
end
end
list_names = List.all.to_a.collect(&:name).sort.uniq
p list_names
list_ids = list_names.collect{|list_name| List.where(name: list_name).first.id}
assert(list_ids.count > 0)
Benchmark.bm(20) do |x|
x.report('individual updates') { individual_updates(list_ids, 100) }
x.report('bulk updates') { bulk_updates(list_ids, 100) }
end
pp Product.all.to_a
db_command = bulk_command(list_ids, 1)
assert(db_command[:updates].size > 0)
pp db_command
end
end
rake test
Run options:
[1/2] ProductTest
Mongoid::VERSION:3.1.6
Moped::VERSION:1.5.2
[2/2] ProductTest
["ASUS", "Android", "Apple", "LG", "Microsoft", "Samsung", "Windows 8 RT", "iOS", "phone", "tablet"]
user system total real
individual updates 0.420000 0.070000 0.490000 ( 0.489579)
bulk updates 0.060000 0.000000 0.060000 ( 0.180926)
[
{:update=>"products",
:updates=>
[{"q"=>{"list_ids"=>"5408b72c7f11bad1ca000002"},
"u"=>{"$inc"=>{"stock"=>0}},
"multi"=>true},
{"q"=>{"list_ids"=>"5408b72c7f11bad1ca000004"},
"u"=>{"$inc"=>{"stock"=>1}},
"multi"=>true},
{"q"=>{"list_ids"=>"5408b72c7f11bad1ca000006"},
"u"=>{"$inc"=>{"stock"=>2}},
"multi"=>true},
{"q"=>{"list_ids"=>"5408b72c7f11bad1ca00000d"},
"u"=>{"$inc"=>{"stock"=>3}},
"multi"=>true},
{"q"=>{"list_ids"=>"5408b72c7f11bad1ca000010"},
"u"=>{"$inc"=>{"stock"=>4}},
"multi"=>true},
{"q"=>{"list_ids"=>"5408b72c7f11bad1ca000013"},
"u"=>{"$inc"=>{"stock"=>5}},
"multi"=>true},
{"q"=>{"list_ids"=>"5408b72c7f11bad1ca000011"},
"u"=>{"$inc"=>{"stock"=>6}},
"multi"=>true},
{"q"=>{"list_ids"=>"5408b72c7f11bad1ca000007"},
"u"=>{"$inc"=>{"stock"=>7}},
"multi"=>true},
{"q"=>{"list_ids"=>"5408b72c7f11bad1ca00000a"},
"u"=>{"$inc"=>{"stock"=>8}},
"multi"=>true},
{"q"=>{"list_ids"=>"5408b72c7f11bad1ca000003"},
"u"=>{"$inc"=>{"stock"=>9}},
"multi"=>true}],
:ordered=>false}
Finished tests in 1.334821s, 1.4983 tests/s, 1.4983 assertions/s.
2 tests, 2 assertions, 0 failures, 0 errors, 0 skips
