mongdb慢查询分析，哪里出了问题？

Question

{
  "op": "query",
  "ns": "fund_statistic.fund_minute_statistic_collection1588",
  "command": {
    "find": "fund_minute_statistic_collection1588",
    "filter": {
      "time": {
        "$gte": 1531868400,
        "$lt": 1531887084
      }
    },
    "$db": "fund_statistic",
    "$readPreference": {
      "mode": "primaryPreferred"
    },
    "lsid": {
      "id": UUID(
      "f0a2ea9e-f8a4-484f-86cc-d01d04ebea3e"
      )
    }
  },
  "cursorid": NumberLong(
  "119871802965176"
  ),
  "keysExamined": 101,
  "docsExamined": 101,
  "numYield": 1,
  "locks": {
    "Global": {
      "acquireCount": {
        "r": NumberLong(4)
      }
    },
    "Database": {
      "acquireCount": {
        "r": NumberLong(2)
      }
    },
    "Collection": {
      "acquireCount": {
        "r": NumberLong(2)
      }
    }
  },
  "nreturned": 101,
  "responseLength": 7185,
  "protocol": "op_msg",
  "millis": 8960,
  "planSummary": "IXSCAN { time: 1 }",
  "execStats": {
    "stage": "FETCH",
    "nReturned": 101,
    "executionTimeMillisEstimate": 119,
    "works": 101,
    "advanced": 101,
    "needTime": 0,
    "needYield": 0,
    "saveState": 2,
    "restoreState": 1,
    "isEOF": 0,
    "invalidates": 0,
    "docsExamined": 101,
    "alreadyHasObj": 0,
    "inputStage": {
      "stage": "IXSCAN",
      "nReturned": 101,
      "executionTimeMillisEstimate": 119,
      "works": 101,
      "advanced": 101,
      "needTime": 0,
      "needYield": 0,
      "saveState": 2,
      "restoreState": 1,
      "isEOF": 0,
      "invalidates": 0,
      "keyPattern": {
        "time": NumberLong(1)
      },
      "indexName": "time_1",
      "isMultiKey": false,
      "multiKeyPaths": {
        "time": []
      },
      "isUnique": false,
      "isSparse": false,
      "isPartial": false,
      "indexVersion": 2,
      "direction": "forward",
      "indexBounds": {
        "time": [
          "[1531868400, 1531887084)"
        ]
      },
      "keysExamined": 101,
      "seeks": 1,
      "dupsTested": 0,
      "dupsDropped": 0,
      "seenInvalidated": 0
    }
  },
  "ts": ISODate(
  "2018-07-18T04:11:33.487Z"
  ),
  "client": "192.168.10.81",
  "allUsers": [],
  "user": ""
}

Answer 1

你可能没有对 time 字段做索引。没做索引的话，查询就是线性的。遍历数据库中的条目就很久了。
可以看看 db.collection.getIndexes() 能获取你现在的缓存列表。
如果没有，并且这个业务场景比较常用可以对 time 字段做索引 db.collection.createIndex({time: 1})