MongoDB获取长数组很慢

Question

因此，我们在mongo的数组中列出了2000到100,000个项目。我想把它用来使用。

说明显示它正在使用索引并且只扫描1个文档。但运行需要1.5 - 3秒。我假设因为大阵列。是否还有加快速度的速度？我觉得被困在那里。

这是查询

db.monitors.find({userId: "xxxx"})

这是解释

{
    "queryPlanner" : {
        "plannerVersion" : 1,
        "namespace" : "xx.monitors",
        "indexFilterSet" : false,
        "parsedQuery" : {
            "userId" : {
                "$eq" : "xxx"
            }
        },
        "winningPlan" : {
            "stage" : "FETCH",
            "inputStage" : {
                "stage" : "IXSCAN",
                "keyPattern" : {
                    "userId" : 1
                },
                "indexName" : "user",
                "isMultiKey" : false,
                "direction" : "forward",
                "indexBounds" : {
                    "userId" : [ 
                        "[\"xxx\", \"xxx\"]"
                    ]
                }
            }
        },
        "rejectedPlans" : []
    },
    "executionStats" : {
        "executionSuccess" : true,
        "nReturned" : 1,
        "executionTimeMillis" : 0,
        "totalKeysExamined" : 1,
        "totalDocsExamined" : 1,
        "executionStages" : {
            "stage" : "FETCH",
            "nReturned" : 1,
            "executionTimeMillisEstimate" : 0,
            "works" : 2,
            "advanced" : 1,
            "needTime" : 0,
            "needFetch" : 0,
            "saveState" : 0,
            "restoreState" : 0,
            "isEOF" : 1,
            "invalidates" : 0,
            "docsExamined" : 1,
            "alreadyHasObj" : 0,
            "inputStage" : {
                "stage" : "IXSCAN",
                "nReturned" : 1,
                "executionTimeMillisEstimate" : 0,
                "works" : 2,
                "advanced" : 1,
                "needTime" : 0,
                "needFetch" : 0,
                "saveState" : 0,
                "restoreState" : 0,
                "isEOF" : 1,
                "invalidates" : 0,
                "keyPattern" : {
                    "userId" : 1
                },
                "indexName" : "user",
                "isMultiKey" : false,
                "direction" : "forward",
                "indexBounds" : {
                    "userId" : [ 
                        "[\"xxx\", \"xxx\"]"
                    ]
                },
                "keysExamined" : 1,
                "dupsTested" : 0,
                "dupsDropped" : 0,
                "seenInvalidated" : 0,
                "matchTested" : 0
            }
        },
        "allPlansExecution" : []
    },
    "serverInfo" : {
        "host" : "xx",
        "port" : 27017,
        "version" : "3.0.4",
        "gitVersion" : "0481c958daeb2969800511e7475dc66986fa9ed5"
    }
}