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怒钢DBA系列-mongo索引篇

mongo 凶恶的方块 1594次浏览 已收录 1个评论

前言:

此话题说来话长,老大让写多个查询接口,尽量考虑索引使用,因为数据非常多,不使用索引查询很慢,于是乎,我写了一个通用查询接口,指定索引生成query对象。根据mongo权威指南的说法 建立复合索引 A_1_B_1_C_1 此时可用索引为 A-B-C |A-B| A  三种, 跟DBA说了讨论了这个问题(PS:我也不想讨论但是已经写完了真的懒得改了),老大又说不能使用通用的DB层查询接口,索引也要为业务服务,于是乎我们3个人开始验证索引顺序对查询的影响,半小时被打N次脸,难道mongo权威指南是盗版书?  DBA 测试 A-B 和 B-A 都是用复合索引 A_1_B_1_C_1 且实际扫描文档数 和 返回文档树一致 2者相同。这就有点不科学了。但事实就摆在那里。。。一定有什么误会于是回家做实验了。

结论(PS 正文太长放结论先):

假设存在索引 A_1_B_1_C_1

AB与BA 都可以正常使用索引效率相同

AC 可使用索引效率较低

BC 不可使用索引 进入 COLLSCAN stage

AXBC 可使用索引与ABCX效率相同

A:{$exists:true}BC 可使用索引  KEEP_MUTATIONS stage  需要复验后返回对性能有影响(很小)

SORT 情况

sort 情况顺序不可变,不可出现 AC 此时无法使用索引排序进入 SORT stage 是、排序效率降低。

即A存在在查询方面可无视对象排序,只排序时关注索引定义。prefix原则是只要存在index首字段即可并不需要考虑位置。

正文:

以公司的测试服务器的数据做实验 ,执行db.collection.getIndexes() 方法,此文档有大约27万数据。我们使用第8个复合索引作为测试索引

{
	"v" : 1,
	"key" : {
		"state" : 1,
		"user" : 1,
		"stock" : 1
	},
	"name" : "state_1_user_1_stock_1",
	"ns" : "mango_order.od_reservations",
	"background" : true
}

我们来看最佳 explain 即ABC db.od_reservations.find({state:1,user:32432424,stock:3243242}).explain(“executionStats”)

{
	"queryPlanner" : {
		"plannerVersion" : 1,
		"namespace" : "mango_order.od_reservations",
		"indexFilterSet" : false,
		"parsedQuery" : {
			"$and" : [
				{
					"state" : {
						"$eq" : 1
					}
				},
				{
					"stock" : {
						"$eq" : 3243242
					}
				}
			]
		},
		"winningPlan" : {
			"stage" : "FETCH",
			"inputStage" : {
				"stage" : "IXSCAN",
				"keyPattern" : {
					"state" : 1,
					"user" : 1,
					"stock" : 1
				},
				"indexName" : "state_1_user_1_stock_1",
				"isMultiKey" : false,
				"isUnique" : false,
				"isSparse" : false,
				"isPartial" : false,
				"indexVersion" : 1,
				"direction" : "forward",
				"indexBounds" : {
					"state" : [
						"[1.0, 1.0]"
					],
					"user" : [
						"[MinKey, MaxKey]"
					],
					"stock" : [
						"[3243242.0, 3243242.0]"
					]
				}
			}
		},
		"rejectedPlans" : [ ]
	},
	"executionStats" : {
		"executionSuccess" : true,
		"nReturned" : 0,
		"executionTimeMillis" : 157,
		"totalKeysExamined" : 29806,
		"totalDocsExamined" : 0,
		"executionStages" : {
			"stage" : "FETCH",
			"nReturned" : 0,
			"executionTimeMillisEstimate" : 160,
			"works" : 29806,
			"advanced" : 0,
			"needTime" : 29805,
			"needYield" : 0,
			"saveState" : 232,
			"restoreState" : 232,
			"isEOF" : 1,
			"invalidates" : 0,
			"docsExamined" : 0,
			"alreadyHasObj" : 0,
			"inputStage" : {
				"stage" : "IXSCAN",
				"nReturned" : 0,
				"executionTimeMillisEstimate" : 160,
				"works" : 29806,
				"advanced" : 0,
				"needTime" : 29805,
				"needYield" : 0,
				"saveState" : 232,
				"restoreState" : 232,
				"isEOF" : 1,
				"invalidates" : 0,
				"keyPattern" : {
					"state" : 1,
					"user" : 1,
					"stock" : 1
				},
				"indexName" : "state_1_user_1_stock_1",
				"isMultiKey" : false,
				"isUnique" : false,
				"isSparse" : false,
				"isPartial" : false,
				"indexVersion" : 1,
				"direction" : "forward",
				"indexBounds" : {
					"state" : [
						"[1.0, 1.0]"
					],
					"user" : [
						"[MinKey, MaxKey]"
					],
					"stock" : [
						"[3243242.0, 3243242.0]"
					]
				},
				"keysExamined" : 29806,
				"dupsTested" : 0,
				"dupsDropped" : 0,
				"seenInvalidated" : 0
			}
		}
	},
	"serverInfo" : {
		"host" : "mango",
		"port" : 27017,
		"version" : "3.2.8",
		"gitVersion" : "ed70e33130c977bda0024c125b56d159573dbaf0"
	},
	"ok" : 1
}

接下来尝试 A_C 检索 db.od_reservations.find({state:1,stock:3243242}).explain(“executionStats”) 证明 A_C 使用该复合索引

{
	"queryPlanner" : {
		"plannerVersion" : 1,
		"namespace" : "mango_order.od_reservations",
		"indexFilterSet" : false,
		"parsedQuery" : {
			"$and" : [
				{
					"state" : {
						"$eq" : 1
					}
				},
				{
					"stock" : {
						"$eq" : 3243242
					}
				}
			]
		},
		"winningPlan" : {
			"stage" : "FETCH",
			"inputStage" : {
				"stage" : "IXSCAN",
				"keyPattern" : {
					"state" : 1,
					"user" : 1,
					"stock" : 1
				},
				"indexName" : "state_1_user_1_stock_1",
				"isMultiKey" : false,
				"isUnique" : false,
				"isSparse" : false,
				"isPartial" : false,
				"indexVersion" : 1,
				"direction" : "forward",
				"indexBounds" : {
					"state" : [
						"[1.0, 1.0]"
					],
					"user" : [
						"[MinKey, MaxKey]"
					],
					"stock" : [
						"[3243242.0, 3243242.0]"
					]
				}
			}
		},
		"rejectedPlans" : [ ]
	},
	"executionStats" : {
		"executionSuccess" : true,
		"nReturned" : 0,
		"executionTimeMillis" : 157,
		"totalKeysExamined" : 29806,
		"totalDocsExamined" : 0,
		"executionStages" : {
			"stage" : "FETCH",
			"nReturned" : 0,
			"executionTimeMillisEstimate" : 160,
			"works" : 29806,
			"advanced" : 0,
			"needTime" : 29805,
			"needYield" : 0,
			"saveState" : 232,
			"restoreState" : 232,
			"isEOF" : 1,
			"invalidates" : 0,
			"docsExamined" : 0,
			"alreadyHasObj" : 0,
			"inputStage" : {
				"stage" : "IXSCAN",
				"nReturned" : 0,
				"executionTimeMillisEstimate" : 160,
				"works" : 29806,
				"advanced" : 0,
				"needTime" : 29805,
				"needYield" : 0,
				"saveState" : 232,
				"restoreState" : 232,
				"isEOF" : 1,
				"invalidates" : 0,
				"keyPattern" : {
					"state" : 1,
					"user" : 1,
					"stock" : 1
				},
				"indexName" : "state_1_user_1_stock_1",
				"isMultiKey" : false,
				"isUnique" : false,
				"isSparse" : false,
				"isPartial" : false,
				"indexVersion" : 1,
				"direction" : "forward",
				"indexBounds" : {
					"state" : [
						"[1.0, 1.0]"
					],
					"user" : [
						"[MinKey, MaxKey]"
					],
					"stock" : [
						"[3243242.0, 3243242.0]"
					]
				},
				"keysExamined" : 29806,
				"dupsTested" : 0,
				"dupsDropped" : 0,
				"seenInvalidated" : 0
			}
		}
	},
	"serverInfo" : {
		"host" : "mango",
		"port" : 27017,
		"version" : "3.2.8",
		"gitVersion" : "ed70e33130c977bda0024c125b56d159573dbaf0"
	},
	"ok" : 1
}

接下来验证 _BC db.od_reservations.find({user:32432424,stock:3243242}).explain(“executionStats”) 证明 _BC 不使用索引

{
	"queryPlanner" : {
		"plannerVersion" : 1,
		"namespace" : "mango_order.od_reservations",
		"indexFilterSet" : false,
		"parsedQuery" : {
			"$and" : [
				{
					"stock" : {
						"$eq" : 3243242
					}
				},
				{
					"user" : {
						"$eq" : 32432424
					}
				}
			]
		},
		"winningPlan" : {
			"stage" : "COLLSCAN",
			"filter" : {
				"$and" : [
					{
						"stock" : {
							"$eq" : 3243242
						}
					},
					{
						"user" : {
							"$eq" : 32432424
						}
					}
				]
			},
			"direction" : "forward"
		},
		"rejectedPlans" : [ ]
	},
	"executionStats" : {
		"executionSuccess" : true,
		"nReturned" : 0,
		"executionTimeMillis" : 92,
		"totalKeysExamined" : 0,
		"totalDocsExamined" : 277389,
		"executionStages" : {
			"stage" : "COLLSCAN",
			"filter" : {
				"$and" : [
					{
						"stock" : {
							"$eq" : 3243242
						}
					},
					{
						"user" : {
							"$eq" : 32432424
						}
					}
				]
			},
			"nReturned" : 0,
			"executionTimeMillisEstimate" : 80,
			"works" : 277401,
			"advanced" : 0,
			"needTime" : 277390,
			"needYield" : 10,
			"saveState" : 2171,
			"restoreState" : 2171,
			"isEOF" : 1,
			"invalidates" : 0,
			"direction" : "forward",
			"docsExamined" : 277389
		}
	},
	"serverInfo" : {
		"host" : "mango",
		"port" : 27017,
		"version" : "3.2.8",
		"gitVersion" : "ed70e33130c977bda0024c125b56d159573dbaf0"
	},
	"ok" : 1
}

接下来验证 BA 是否使用索引 db.od_reservations.find({user:32432424,state:1}).explain(“executionStats”) 证明DBA正确,此时使用了复合索引 我们接下来看看和AB是否有性能差距

{
	"queryPlanner" : {
		"plannerVersion" : 1,
		"namespace" : "mango_order.od_reservations",
		"indexFilterSet" : false,
		"parsedQuery" : {
			"$and" : [
				{
					"state" : {
						"$eq" : 1
					}
				},
				{
					"user" : {
						"$eq" : 32432424
					}
				}
			]
		},
		"winningPlan" : {
			"stage" : "FETCH",
			"inputStage" : {
				"stage" : "IXSCAN",
				"keyPattern" : {
					"state" : 1,
					"user" : 1,
					"stock" : 1
				},
				"indexName" : "state_1_user_1_stock_1",
				"isMultiKey" : false,
				"isUnique" : false,
				"isSparse" : false,
				"isPartial" : false,
				"indexVersion" : 1,
				"direction" : "forward",
				"indexBounds" : {
					"state" : [
						"[1.0, 1.0]"
					],
					"user" : [
						"[32432424.0, 32432424.0]"
					],
					"stock" : [
						"[MinKey, MaxKey]"
					]
				}
			}
		},
		"rejectedPlans" : [ ]
	},
	"executionStats" : {
		"executionSuccess" : true,
		"nReturned" : 0,
		"executionTimeMillis" : 0,
		"totalKeysExamined" : 0,
		"totalDocsExamined" : 0,
		"executionStages" : {
			"stage" : "FETCH",
			"nReturned" : 0,
			"executionTimeMillisEstimate" : 0,
			"works" : 1,
			"advanced" : 0,
			"needTime" : 0,
			"needYield" : 0,
			"saveState" : 0,
			"restoreState" : 0,
			"isEOF" : 1,
			"invalidates" : 0,
			"docsExamined" : 0,
			"alreadyHasObj" : 0,
			"inputStage" : {
				"stage" : "IXSCAN",
				"nReturned" : 0,
				"executionTimeMillisEstimate" : 0,
				"works" : 1,
				"advanced" : 0,
				"needTime" : 0,
				"needYield" : 0,
				"saveState" : 0,
				"restoreState" : 0,
				"isEOF" : 1,
				"invalidates" : 0,
				"keyPattern" : {
					"state" : 1,
					"user" : 1,
					"stock" : 1
				},
				"indexName" : "state_1_user_1_stock_1",
				"isMultiKey" : false,
				"isUnique" : false,
				"isSparse" : false,
				"isPartial" : false,
				"indexVersion" : 1,
				"direction" : "forward",
				"indexBounds" : {
					"state" : [
						"[1.0, 1.0]"
					],
					"user" : [
						"[32432424.0, 32432424.0]"
					],
					"stock" : [
						"[MinKey, MaxKey]"
					]
				},
				"keysExamined" : 0,
				"dupsTested" : 0,
				"dupsDropped" : 0,
				"seenInvalidated" : 0
			}
		}
	},
	"serverInfo" : {
		"host" : "mango",
		"port" : 27017,
		"version" : "3.2.8",
		"gitVersion" : "ed70e33130c977bda0024c125b56d159573dbaf0"
	},
	"ok" : 1
}

验证 AB db.od_reservations.find({state:1,user:32432424}).explain(“executionStats”) 证明 BA与AB索引效率相同,AB可高效使用索引而AC则不行。

{
	"queryPlanner" : {
		"plannerVersion" : 1,
		"namespace" : "mango_order.od_reservations",
		"indexFilterSet" : false,
		"parsedQuery" : {
			"$and" : [
				{
					"state" : {
						"$eq" : "1703282329098"
					}
				},
				{
					"user" : {
						"$eq" : 32432424
					}
				}
			]
		},
		"winningPlan" : {
			"stage" : "FETCH",
			"inputStage" : {
				"stage" : "IXSCAN",
				"keyPattern" : {
					"state" : 1,
					"user" : 1,
					"stock" : 1
				},
				"indexName" : "state_1_user_1_stock_1",
				"isMultiKey" : false,
				"isUnique" : false,
				"isSparse" : false,
				"isPartial" : false,
				"indexVersion" : 1,
				"direction" : "forward",
				"indexBounds" : {
					"state" : [
						"[\"1703282329098\", \"1703282329098\"]"
					],
					"user" : [
						"[32432424.0, 32432424.0]"
					],
					"stock" : [
						"[MinKey, MaxKey]"
					]
				}
			}
		},
		"rejectedPlans" : [ ]
	},
	"executionStats" : {
		"executionSuccess" : true,
		"nReturned" : 0,
		"executionTimeMillis" : 0,
		"totalKeysExamined" : 0,
		"totalDocsExamined" : 0,
		"executionStages" : {
			"stage" : "FETCH",
			"nReturned" : 0,
			"executionTimeMillisEstimate" : 0,
			"works" : 1,
			"advanced" : 0,
			"needTime" : 0,
			"needYield" : 0,
			"saveState" : 0,
			"restoreState" : 0,
			"isEOF" : 1,
			"invalidates" : 0,
			"docsExamined" : 0,
			"alreadyHasObj" : 0,
			"inputStage" : {
				"stage" : "IXSCAN",
				"nReturned" : 0,
				"executionTimeMillisEstimate" : 0,
				"works" : 1,
				"advanced" : 0,
				"needTime" : 0,
				"needYield" : 0,
				"saveState" : 0,
				"restoreState" : 0,
				"isEOF" : 1,
				"invalidates" : 0,
				"keyPattern" : {
					"state" : 1,
					"user" : 1,
					"stock" : 1
				},
				"indexName" : "state_1_user_1_stock_1",
				"isMultiKey" : false,
				"isUnique" : false,
				"isSparse" : false,
				"isPartial" : false,
				"indexVersion" : 1,
				"direction" : "forward",
				"indexBounds" : {
					"state" : [
						"[\"1703282329098\", \"1703282329098\"]"
					],
					"user" : [
						"[32432424.0, 32432424.0]"
					],
					"stock" : [
						"[MinKey, MaxKey]"
					]
				},
				"keysExamined" : 0,
				"dupsTested" : 0,
				"dupsDropped" : 0,
				"seenInvalidated" : 0
			}
		}
	},
	"serverInfo" : {
		"host" : "mango",
		"port" : 27017,
		"version" : "3.2.8",
		"gitVersion" : "ed70e33130c977bda0024c125b56d159573dbaf0"
	},
	"ok" : 1
}

验证 $exists A:$exists—B db.od_reservations.find({state:{$exists: true},user:32432424}).explain(“executionStats”) 结论 $exites 返回多结果对性能有影响(
KEEP_UTATIONS stage 表示检索到结果后,在检索过程中的删除或者修改,会触发一个复验的过程,当复验成功文档将被返回

{
	"queryPlanner" : {
		"plannerVersion" : 1,
		"namespace" : "mango_order.od_reservations",
		"indexFilterSet" : false,
		"parsedQuery" : {
			"$and" : [
				{
					"user" : {
						"$eq" : 32432424
					}
				},
				{
					"state" : {
						"$exists" : true
					}
				}
			]
		},
		"winningPlan" : {
			"stage" : "KEEP_MUTATIONS",
			"inputStage" : {
				"stage" : "FETCH",
				"filter" : {
					"state" : {
						"$exists" : true
					}
				},
				"inputStage" : {
					"stage" : "IXSCAN",
					"keyPattern" : {
						"state" : 1,
						"user" : 1,
						"stock" : 1
					},
					"indexName" : "state_1_user_1_stock_1",
					"isMultiKey" : false,
					"isUnique" : false,
					"isSparse" : false,
					"isPartial" : false,
					"indexVersion" : 1,
					"direction" : "forward",
					"indexBounds" : {
						"state" : [
							"[MinKey, MaxKey]"
						],
						"user" : [
							"[32432424.0, 32432424.0]"
						],
						"stock" : [
							"[MinKey, MaxKey]"
						]
					}
				}
			}
		},
		"rejectedPlans" : [ ]
	},
	"executionStats" : {
		"executionSuccess" : true,
		"nReturned" : 0,
		"executionTimeMillis" : 0,
		"totalKeysExamined" : 3,
		"totalDocsExamined" : 0,
		"executionStages" : {
			"stage" : "KEEP_MUTATIONS",
			"nReturned" : 0,
			"executionTimeMillisEstimate" : 0,
			"works" : 4,
			"advanced" : 0,
			"needTime" : 3,
			"needYield" : 0,
			"saveState" : 0,
			"restoreState" : 0,
			"isEOF" : 1,
			"invalidates" : 0,
			"inputStage" : {
				"stage" : "FETCH",
				"filter" : {
					"state" : {
						"$exists" : true
					}
				},
				"nReturned" : 0,
				"executionTimeMillisEstimate" : 0,
				"works" : 4,
				"advanced" : 0,
				"needTime" : 3,
				"needYield" : 0,
				"saveState" : 0,
				"restoreState" : 0,
				"isEOF" : 1,
				"invalidates" : 0,
				"docsExamined" : 0,
				"alreadyHasObj" : 0,
				"inputStage" : {
					"stage" : "IXSCAN",
					"nReturned" : 0,
					"executionTimeMillisEstimate" : 0,
					"works" : 4,
					"advanced" : 0,
					"needTime" : 3,
					"needYield" : 0,
					"saveState" : 0,
					"restoreState" : 0,
					"isEOF" : 1,
					"invalidates" : 0,
					"keyPattern" : {
						"state" : 1,
						"user" : 1,
						"stock" : 1
					},
					"indexName" : "state_1_user_1_stock_1",
					"isMultiKey" : false,
					"isUnique" : false,
					"isSparse" : false,
					"isPartial" : false,
					"indexVersion" : 1,
					"direction" : "forward",
					"indexBounds" : {
						"state" : [
							"[MinKey, MaxKey]"
						],
						"user" : [
							"[32432424.0, 32432424.0]"
						],
						"stock" : [
							"[MinKey, MaxKey]"
						]
					},
					"keysExamined" : 3,
					"dupsTested" : 0,
					"dupsDropped" : 0,
					"seenInvalidated" : 0
				}
			}
		}
	},
	"serverInfo" : {
		"host" : "mango",
		"port" : 27017,
		"version" : "3.2.8",
		"gitVersion" : "ed70e33130c977bda0024c125b56d159573dbaf0"
	},
	"ok" : 1
}

sort情况 db.od_reservations.find({state:{$exists:true},user:{$exists:true},stock:{$exists:true}}).sort({ state:1, stock:1}).explain(“executionStats”)

进行多种测试证明 sort排序时不能使用 AC BC 等索引 属于 SORT stage

{
	"queryPlanner" : {
		"plannerVersion" : 1,
		"namespace" : "mango_order.od_reservations",
		"indexFilterSet" : false,
		"parsedQuery" : {
			"$and" : [
				{
					"state" : {
						"$exists" : true
					}
				},
				{
					"stock" : {
						"$exists" : true
					}
				},
				{
					"user" : {
						"$exists" : true
					}
				}
			]
		},
		"winningPlan" : {
			"stage" : "SORT",
			"sortPattern" : {
				"state" : 1,
				"stock" : 1
			},
			"inputStage" : {
				"stage" : "KEEP_MUTATIONS",
				"inputStage" : {
					"stage" : "SORT_KEY_GENERATOR",
					"inputStage" : {
						"stage" : "FETCH",
						"filter" : {
							"$and" : [
								{
									"state" : {
										"$exists" : true
									}
								},
								{
									"user" : {
										"$exists" : true
									}
								},
								{
									"stock" : {
										"$exists" : true
									}
								}
							]
						},
						"inputStage" : {
							"stage" : "IXSCAN",
							"keyPattern" : {
								"state" : 1,
								"user" : 1,
								"stock" : 1
							},
							"indexName" : "state_1_user_1_stock_1",
							"isMultiKey" : false,
							"isUnique" : false,
							"isSparse" : false,
							"isPartial" : false,
							"indexVersion" : 1,
							"direction" : "forward",
							"indexBounds" : {
								"state" : [
									"[MinKey, MaxKey]"
								],
								"user" : [
									"[MinKey, MaxKey]"
								],
								"stock" : [
									"[MinKey, MaxKey]"
								]
							}
						}
					}
				}
			}
		},
		"rejectedPlans" : [ ]
	},
	"executionStats" : {
		"executionSuccess" : false,
		"errorMessage" : "Exec error: OperationFailed: Sort operation used more than the maximum 33554432 bytes of RAM. Add an index, or specify a smaller limit., state: FAILURE",
		"errorCode" : 96,
		"nReturned" : 0,
		"executionTimeMillis" : 313,
		"totalKeysExamined" : 101140,
		"totalDocsExamined" : 101140,
		"executionStages" : {
			"stage" : "SORT",
			"nReturned" : 0,
			"executionTimeMillisEstimate" : 310,
			"works" : 101142,
			"advanced" : 0,
			"needTime" : 101141,
			"needYield" : 0,
			"saveState" : 790,
			"restoreState" : 790,
			"isEOF" : 0,
			"invalidates" : 0,
			"sortPattern" : {
				"state" : 1,
				"stock" : 1
			},
			"memUsage" : 33554524,
			"memLimit" : 33554432,
			"inputStage" : {
				"stage" : "KEEP_MUTATIONS",
				"nReturned" : 101140,
				"executionTimeMillisEstimate" : 260,
				"works" : 101141,
				"advanced" : 101140,
				"needTime" : 1,
				"needYield" : 0,
				"saveState" : 790,
				"restoreState" : 790,
				"isEOF" : 0,
				"invalidates" : 0,
				"inputStage" : {
					"stage" : "SORT_KEY_GENERATOR",
					"nReturned" : 0,
					"executionTimeMillisEstimate" : 260,
					"works" : 101141,
					"advanced" : 0,
					"needTime" : 1,
					"needYield" : 0,
					"saveState" : 790,
					"restoreState" : 790,
					"isEOF" : 0,
					"invalidates" : 0,
					"inputStage" : {
						"stage" : "FETCH",
						"filter" : {
							"$and" : [
								{
									"state" : {
										"$exists" : true
									}
								},
								{
									"user" : {
										"$exists" : true
									}
								},
								{
									"stock" : {
										"$exists" : true
									}
								}
							]
						},
						"nReturned" : 101140,
						"executionTimeMillisEstimate" : 200,
						"works" : 101140,
						"advanced" : 101140,
						"needTime" : 0,
						"needYield" : 0,
						"saveState" : 790,
						"restoreState" : 790,
						"isEOF" : 0,
						"invalidates" : 0,
						"docsExamined" : 101140,
						"alreadyHasObj" : 0,
						"inputStage" : {
							"stage" : "IXSCAN",
							"nReturned" : 101140,
							"executionTimeMillisEstimate" : 40,
							"works" : 101140,
							"advanced" : 101140,
							"needTime" : 0,
							"needYield" : 0,
							"saveState" : 790,
							"restoreState" : 790,
							"isEOF" : 0,
							"invalidates" : 0,
							"keyPattern" : {
								"state" : 1,
								"user" : 1,
								"stock" : 1
							},
							"indexName" : "state_1_user_1_stock_1",
							"isMultiKey" : false,
							"isUnique" : false,
							"isSparse" : false,
							"isPartial" : false,
							"indexVersion" : 1,
							"direction" : "forward",
							"indexBounds" : {
								"state" : [
									"[MinKey, MaxKey]"
								],
								"user" : [
									"[MinKey, MaxKey]"
								],
								"stock" : [
									"[MinKey, MaxKey]"
								]
							},
							"keysExamined" : 101140,
							"dupsTested" : 0,
							"dupsDropped" : 0,
							"seenInvalidated" : 0
						}
					}
				}
			}
		}
	},
	"serverInfo" : {
		"host" : "mango",
		"port" : 27017,
		"version" : "3.2.8",
		"gitVersion" : "ed70e33130c977bda0024c125b56d159573dbaf0"
	},
	"ok" : 1
}

 


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