Understanding MapReduce in MongoDB, with Node.js, PHP (and Drupal) - Ben Buckman - Software architect
Understanding MapReduce in MongoDB, with Node.js, PHP (and Drupal) (Note, some of the details in this post may be outdated. For example, MongoDB now supports Aggregation queries which simplify some of these use cases. However, the MapReduce concepts are probably still the same.) MongoDB’s query language is good at extracting whole documents or whole elements of a document, but on its own it can’t
Mongooseã§map-reduceã—ã¦ã„る時ã«åµŒã£ãŸã“ã¨ã€‚ - Qiita
var command = { mapreduce:"communications", query:query, map:communicationCountMapFunc, reduce:communicationCountReduceFunc, out:'communications_mr_buf' }; var dbh = new DPH(Promise); //ã“ã‚Œã¯Promiseã‚’DB対応ã•ã›ã‚‹ãƒ©ãƒƒãƒ‘ mongoose.connection.db.executeDbCommand(command, dbh.handler(function (ret) { return ret.documents[0]; })); return dbh.promise;
MapReduce - Docs-Japanese - 10gen Confluence
shard環境ä¸ã§ã¯ã€ã™ã¹ã¦ã®shardã§ä¸¦è¡Œã—ã¦ãƒ‡ãƒ¼ã‚¿å‡¦ç†ãŒèµ°ã‚Šã¾ã™ã€‚  (注æ„: 2010/2/2: shard内ã§ã®map/reduceã¯ãƒšãƒ³ãƒ†ã‚£ãƒ³ã‚°ä¸ã§ã™ãŒã€ã™ãã«æˆ»ã‚Šã¾ã™) map/reduce ã¯ãƒ‡ãƒ¼ã‚¿ãƒ™ãƒ¼ã‚¹ [command] を経由ã—ã¦ã€å‘¼ã³å‡ºã•ã‚Œã¾ã™ã€‚  データãƒãƒ¼ã‚¹ã¯ä¸€æ™‚çš„ãªã‚³ãƒ¬ã‚¯ã‚·ãƒ§ãƒ³ã‚’出力çµæžœç”¨ã«ä½œæˆã—ã¾ã™ã€‚ã“ã®ä¸€æ™‚çš„ãªã‚³ãƒ¬ã‚¯ã‚·ãƒ§ãƒ³ã¯ã€ã‚¯ãƒ©ã‚¤ã‚¢ãƒ³ãƒˆã®ã‚³ãƒã‚¯ã‚·ãƒ§ãƒ³ãŒé–‰ã˜ãŸã¨ãã€ã¾ãŸã¯æ˜Žç¤ºçš„ã«dropã•ã‚ŒãŸå ´åˆå‰Šé™¤ã•ã‚Œã¾ã™ã€‚ã¾ãŸã€æ°¸ç¶šçš„ãªå‡ºåŠ›ç”¨ã®ã‚³ãƒ¬ã‚¯ã‚·ãƒ§ãƒ³åを指定ã™ã‚‹ã“ã¨ã‚‚ã§ãã¾ã™ã€‚ map 㨠reduce ファンクションã¯JavaScriptã§æ›¸ãã€ã‚µãƒ¼ãƒä¸Šã§å®Ÿè¡Œã•ã‚Œã¾ã™ã€‚ コマンドã®æ–‡æ³•: db.runCommand( { mapreduce : <collection>, map : <map ファンクションå>, reduce : <reduce フ
ドã‚ュメント指å‘データベースMongoDB [9] - オブãƒã‚°
ã“ã‚“ã«ã¡ã¯ã€ursmã§ã™ã€‚ 今回ã¯MongoDBã®åˆ†æ•£å‡¦ç†æ©Ÿæ§‹ã€MapReduceã«ã¤ã„ã¦ã”紹介ã—ã¾ã™ã€‚ MapReduceã«ã¤ã„ã¦ã®ã”ãç°¡å˜ãªèª¬æ˜Ž ã¨ã«ã‹ããŸãã•ã‚“è¦ç´ ãŒå…¥ã£ã¦ã„ã‚‹é…列を考ãˆã¦ã¿ã¾ã™ã€‚ array = [1, 3, 5, 2, ...] ã“ã®é…列ã«ã¤ã„ã¦ã€å€¤ãŒãã‚Œãžã‚Œä½•å›žå‡ºç¾ã—ãŸã‹æ•°ãˆä¸Šã’ã‚‹ã«ã¯ã©ã†ã—ãŸã‚‰ã„ã„ã§ã—ょã†ã‹ã€‚普通ã«ãã‚‹ãる回ã—ã¦ã‚«ã‚¦ãƒ³ãƒˆã™ã‚‹ã€ã¨ã„ã†ã®ãŒæ€ã„付ãã¾ã™ã。 counts = Hash.new(0) array.each do |i| counts[i] += 1 end counts #=> {1=>1034, 9=>996, 8=>962, ...} ã•ã¦ã€ã‚‚ã—è¦ç´ ãŒ1億個ã‚ã£ãŸã‚‰ã€ã¯ãŸã¾ãŸ1兆個ã‚ã£ãŸã‚‰ã©ã†ã—ã¾ã—ょã†ã‹ã€‚é…列をã„ãã¤ã‹ã«åˆ†ã‘ã¦ãã‚Œãžã‚Œæ•°ãˆä¸Šã’ã€ãã®çµæžœã‚’足ã—åˆã‚ã›ã‚‹â€¦ã¨ã„ã†é¢¨ã«ã™ã‚Œã°çµæžœã¯ä¸€ç·’ã«ãªã‚‹ã¯ãšã§ã™ã。ãã‚Œãžã‚Œã®é…列を数
MongoDB : サルã§ã‚‚ã‚ã‹ã‚‹MapReduceãã®ï¼’：ãƒã‚°ã®æ™‚間別集計を行ㆠ· DQNEO日記
RDBMSã§ã¯ä¸‹è¨˜ã®ã‚ˆã†ãªSQLã«ãªã‚‹ã¨æ€ã„ã¾ã™ã€‚(PostgreSQLã§ã®ä¾‹) SELECT to_char(timestamp, 'yyyy-mm-dd HH24'::text) AS ymdh ,count(*) FROM accesslog WHERE '2011-12-01' <= timestamp AND timestamp < '2011-12-02' GROUP BY ymdh ORDER BY ymdh ; MapReduceを実行ã™ã‚‹ // 日本標準時を扱ã†ãŸã‚ã®ãƒ¦ãƒ¼ãƒ†ã‚£ãƒªãƒ†ã‚£é–¢æ•° var JSTDate = function (str) { return ISODate(str + "T00+09:00"); }; // 日付範囲指定ã§å¯¾è±¡ã‚’絞る。 // ã“ã®ã‚ˆã†ã«ä¸€æ™‚変数ã«è¨˜æ†¶ã•ã›ã¦ãŠãã¨ä¾¿åˆ©ã€‚ var query = { "timestamp" : { "$gt
MongoDB : サルã§ã‚‚ã‚ã‹ã‚‹MapReduce · DQNEO日記
ã¾ãšã¯ã€Œé›†è¨ˆãŒã§ãã‚‹ã€ã¨è¦šãˆã¦ãŠãã¾ã—ょã†ã€‚ 最åˆã¯ã“ã‚Œã ã‘ã§å分ã§ã—ょã†ã€‚ 利用事例 ã‚ã‚‹æ—¥ã€ãƒ”ã‚«ãƒãƒ¥ãƒ¼ãŒã¤ã¶ã‚„ãサービスã§ã¤ã¶ã‚„ã始ã‚ã¾ã—ãŸã€‚ ピカãƒãƒ¥ãƒ¼ã®ã¤ã¶ã‚„ãã«å¯¾ã—ã¦ã€ä»²é–“ã‹ã‚‰ãŸãã•ã‚“ã®ã€Œã„ã„ãï¼ã€ãƒœã‚¿ãƒ³ãŒæŠ¼ã•ã‚Œã¾ã—ãŸã€‚ ã‚ãªãŸã¯ã¤ã¶ã‚„ãサービス管ç†äººã¨ã—ã¦ã€ãƒ”ã‚«ãƒãƒ¥ãƒ¼ã®ã¤ã¶ã‚„ãæ•°ã¨ã€ãƒ”ã‚«ãƒãƒ¥ãƒ¼ãŒã‚²ãƒƒãƒˆã—ãŸã€Œã„ã„ãï¼ã€ã®ãƒˆãƒ¼ã‚¿ãƒ«æ•°ã‚’集計ã—ã¦ã¿ã¾ã—ょã†ã€‚ 準備 Mongoクライアントを起動ã—ã¦ã€DBを作æˆã—ã¾ã—ょã†ã€‚ ./mongodb/bin/mongo MongoDB shell version: 2.0.1 connecting to: test > use sample; switched to db sample サンプルデータ ピカãƒãƒ¥ãƒ¼ãŒï¼“回ã¤ã¶ã‚„ã„ã¦ã€ã€Œã„ã„ãï¼ã€ãŒãŸãã•ã‚“ã¤ãã¾ã—ãŸã€‚ > db.entries.save( {username:'pikachu',
MongoDBã®map/reduceを試ã—ã¦ã¿ã‚‹ã€‚ - stog's blog
以å‰ï¼ˆhttp://d.hatena.ne.jp/stog/20100531/1275317576）作æˆã—ãŸã‚³ãƒ¬ã‚¯ã‚·ãƒ§ãƒ³ã‚’map/reduceを使ã£ã¦"type"別ã«é›†è¨ˆã—ã¦ã¿ã‚‹ã€‚ コレクションã®ä¸èº«ã¯ã“ã‚“ãªæ„Ÿã˜ã€‚ $ mongo mytest MongoDB shell version: 1.4.4 url: mytest connecting to: mytest type "help" for help > > db.members2.find() { "_id" : ObjectId("4c03c632b4742d2998000000"), "birthday" : 342057600, "type" : "human", "name" : "ãŠãŒã‚", "sex" : "M" } { "_id" : ObjectId("4c03c632b4742d2998000001"), "b
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MongoDB: The World’s Leading Modern Database
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