數(shù)據(jù)：大概650萬條，實際查詢花費12秒，該做的索引都做了，12秒太長了。查詢語句：db.attach.find({data_id:{'$in':[ObjectId('595b7d3c0b192c196eb84f87'),ObjectId('595b7d29a2a75c18af7eff2d'),ObjectId('595b7d21adb12b0f86224acc'),ObjectId('595b7d120031d40f881634b8'),ObjectId('595b7d2c88ce6d18afd34dab'),ObjectId('595b7d2a36f526176ba21156'),ObjectId('595b7d1b47c347196d6d26f5'),ObjectId('595b7d1372321718a937f649'),ObjectId('595b7d25fda0d80f289ed24b'),ObjectId('595b7d28ad1a8118a85ff575'),ObjectId('595b7d268d9cfb17b285dff3'),ObjectId('595b7d18adb12b0f8622472d'),ObjectId('595b7d130630360f7f8ded79'),ObjectId('595b7d22b5077e1a668c189d'),ObjectId('595b7d23ab191119de23b9a3'),ObjectId('595b7d1eadb12b0f86224a6d'),ObjectId('595b7d1c72cf8718a10beec9'),ObjectId('595b7d10ad1a8118a85fed1e'),ObjectId('595b7d218c7ff00f9d1ebe2f'),ObjectId('595b7d2547c347196d6d2a80'),ObjectId('595b7d27c7ed9e0f13402dc3'),ObjectId('595b7d18e184ae18b5bfe689'),ObjectId('595b7d178c7ff00f9d1eba66'),ObjectId('595b7d198d9cfb17b285d8a1'),ObjectId('595b7d0ffda0d80f289ec90b')]}}).explain()執(zhí)行結(jié)果：[{queryPlanner:{plannerVersion:1,namespace:"admin.attach",indexFilterSet:false,parsedQuery:{data_id:{$in:[ObjectId("595b7d0ffda0d80f289ec90b"),ObjectId("595b7d10ad1a8118a85fed1e"),ObjectId("595b7d120031d40f881634b8"),ObjectId("595b7d130630360f7f8ded79"),ObjectId("595b7d1372321718a937f649"),ObjectId("595b7d178c7ff00f9d1eba66"),ObjectId("595b7d18adb12b0f8622472d"),ObjectId("595b7d18e184ae18b5bfe689"),ObjectId("595b7d198d9cfb17b285d8a1"),ObjectId("595b7d1b47c347196d6d26f5"),ObjectId("595b7d1c72cf8718a10beec9"),ObjectId("595b7d1eadb12b0f86224a6d"),ObjectId("595b7d218c7ff00f9d1ebe2f"),ObjectId("595b7d21adb12b0f86224acc"),ObjectId("595b7d22b5077e1a668c189d"),ObjectId("595b7d23ab191119de23b9a3"),ObjectId("595b7d2547c347196d6d2a80"),ObjectId("595b7d25fda0d80f289ed24b"),ObjectId("595b7d268d9cfb17b285dff3"),ObjectId("595b7d27c7ed9e0f13402dc3"),ObjectId("595b7d28ad1a8118a85ff575"),ObjectId("595b7d29a2a75c18af7eff2d"),ObjectId("595b7d2a36f526176ba21156"),ObjectId("595b7d2c88ce6d18afd34dab"),ObjectId("595b7d3c0b192c196eb84f87")]}},winningPlan:{stage:"FETCH",inputStage:{stage:"IXSCAN",keyPattern:{data_id:1.0},indexName:"data_id_1.0",isMultiKey:false,isUnique:false,isSparse:false,isPartial:false,indexVersion:1,direction:"forward",indexBounds:{data_id:["[ObjectId('595b7d0ffda0d80f289ec90b'),ObjectId('595b7d0ffda0d80f289ec90b')]","[ObjectId('595b7d10ad1a8118a85fed1e'),ObjectId('595b7d10ad1a8118a85fed1e')]","[ObjectId('595b7d120031d40f881634b8'),ObjectId('595b7d120031d40f881634b8')]","[ObjectId('595b7d130630360f7f8ded79'),ObjectId('595b7d130630360f7f8ded79')]","[ObjectId('595b7d1372321718a937f649'),ObjectId('595b7d1372321718a937f649')]","[ObjectId('595b7d178c7ff00f9d1eba66'),ObjectId('595b7d178c7ff00f9d1eba66')]","[ObjectId('595b7d18adb12b0f8622472d'),ObjectId('595b7d18adb12b0f8622472d')]","[ObjectId('595b7d18e184ae18b5bfe689'),ObjectId('595b7d18e184ae18b5bfe689')]","[ObjectId('595b7d198d9cfb17b285d8a1'),ObjectId('595b7d198d9cfb17b285d8a1')]","[ObjectId('595b7d1b47c347196d6d26f5'),ObjectId('595b7d1b47c347196d6d26f5')]","[ObjectId('595b7d1c72cf8718a10beec9'),ObjectId('595b7d1c72cf8718a10beec9')]","[ObjectId('595b7d1eadb12b0f86224a6d'),ObjectId('595b7d1eadb12b0f86224a6d')]","[ObjectId('595b7d218c7ff00f9d1ebe2f'),ObjectId('595b7d218c7ff00f9d1ebe2f')]","[ObjectId('595b7d21adb12b0f86224acc'),ObjectId('595b7d21adb12b0f86224acc')]","[ObjectId('595b7d22b5077e1a668c189d'),ObjectId('595b7d22b5077e1a668c189d')]","[ObjectId('595b7d23ab191119de23b9a3'),ObjectId('595b7d23ab191119de23b9a3')]","[ObjectId('595b7d2547c347196d6d2a80'),ObjectId('595b7d2547c347196d6d2a80')]","[ObjectId('595b7d25fda0d80f289ed24b'),ObjectId('595b7d25fda0d80f289ed24b')]","[ObjectId('595b7d268d9cfb17b285dff3'),ObjectId('595b7d268d9cfb17b285dff3')]","[ObjectId('595b7d27c7ed9e0f13402dc3'),ObjectId('595b7d27c7ed9e0f13402dc3')]","[ObjectId('595b7d28ad1a8118a85ff575'),ObjectId('595b7d28ad1a8118a85ff575')]","[ObjectId('595b7d29a2a75c18af7eff2d'),ObjectId('595b7d29a2a75c18af7eff2d')]","[ObjectId('595b7d2a36f526176ba21156'),ObjectId('595b7d2a36f526176ba21156')]","[ObjectId('595b7d2c88ce6d18afd34dab'),ObjectId('595b7d2c88ce6d18afd34dab')]","[ObjectId('595b7d3c0b192c196eb84f87'),ObjectId('595b7d3c0b192c196eb84f87')]"]}}},rejectedPlans:[]},executionStats:{executionSuccess:true,nReturned:14842,executionTimeMillis:5881,totalKeysExamined:14867,totalDocsExamined:14842,executionStages:{stage:"FETCH",nReturned:14842,executionTimeMillisEstimate:20,works:14867,advanced:14842,needTime:24,needYield:0,saveState:116,restoreState:116,isEOF:1,invalidates:0,docsExamined:14842,alreadyHasObj:0,inputStage:{stage:"IXSCAN",nReturned:14842,executionTimeMillisEstimate:10,works:14867,advanced:14842,needTime:24,needYield:0,saveState:116,restoreState:116,isEOF:1,invalidates:0,keyPattern:{data_id:1.0},indexName:"data_id_1.0",isMultiKey:false,isUnique:false,isSparse:false,isPartial:false,indexVersion:1,direction:"forward",indexBounds:{data_id:["[ObjectId('595b7d0ffda0d80f289ec90b'),ObjectId('595b7d0ffda0d80f289ec90b')]","[ObjectId('595b7d10ad1a8118a85fed1e'),ObjectId('595b7d10ad1a8118a85fed1e')]","[ObjectId('595b7d120031d40f881634b8'),ObjectId('595b7d120031d40f881634b8')]","[ObjectId('595b7d130630360f7f8ded79'),ObjectId('595b7d130630360f7f8ded79')]","[ObjectId('595b7d1372321718a937f649'),ObjectId('595b7d1372321718a937f649')]","[ObjectId('595b7d178c7ff00f9d1eba66'),ObjectId('595b7d178c7ff00f9d1eba66')]","[ObjectId('595b7d18adb12b0f8622472d'),ObjectId('595b7d18adb12b0f8622472d')]","[ObjectId('595b7d18e184ae18b5bfe689'),ObjectId('595b7d18e184ae18b5bfe689')]","[ObjectId('595b7d198d9cfb17b285d8a1'),ObjectId('595b7d198d9cfb17b285d8a1')]","[ObjectId('595b7d1b47c347196d6d26f5'),ObjectId('595b7d1b47c347196d6d26f5')]","[ObjectId('595b7d1c72cf8718a10beec9'),ObjectId('595b7d1c72cf8718a10beec9')]","[ObjectId('595b7d1eadb12b0f86224a6d'),ObjectId('595b7d1eadb12b0f86224a6d')]","[ObjectId('595b7d218c7ff00f9d1ebe2f'),ObjectId('595b7d218c7ff00f9d1ebe2f')]","[ObjectId('595b7d21adb12b0f86224acc'),ObjectId('595b7d21adb12b0f86224acc')]","[ObjectId('595b7d22b5077e1a668c189d'),ObjectId('595b7d22b5077e1a668c189d')]","[ObjectId('595b7d23ab191119de23b9a3'),ObjectId('595b7d23ab191119de23b9a3')]","[ObjectId('595b7d2547c347196d6d2a80'),ObjectId('595b7d2547c347196d6d2a80')]","[ObjectId('595b7d25fda0d80f289ed24b'),ObjectId('595b7d25fda0d80f289ed24b')]","[ObjectId('595b7d268d9cfb17b285dff3'),ObjectId('595b7d268d9cfb17b285dff3')]","[ObjectId('595b7d27c7ed9e0f13402dc3'),ObjectId('595b7d27c7ed9e0f13402dc3')]","[ObjectId('595b7d28ad1a8118a85ff575'),ObjectId('595b7d28ad1a8118a85ff575')]","[ObjectId('595b7d29a2a75c18af7eff2d'),ObjectId('595b7d29a2a75c18af7eff2d')]","[ObjectId('595b7d2a36f526176ba21156'),ObjectId('595b7d2a36f526176ba21156')]","[ObjectId('595b7d2c88ce6d18afd34dab'),ObjectId('595b7d2c88ce6d18afd34dab')]","[ObjectId('595b7d3c0b192c196eb84f87'),ObjectId('595b7d3c0b192c196eb84f87')]"]},keysExamined:14867,dupsTested:0,dupsDropped:0,seenInvalidated:0}},allPlansExecution:[]}}]