configureQueryAnalyzer (database command数据库命令)

Command Fields命令字段

configureQueryAnalyzer has the following fields:具有以下字段：

Dropped Collections and Renamed Collections删除集合和重命名集合

Query sampling is disabled automatically when the collection is dropped or renamed. If you want to sample queries after a collection is recreated or renamed, you must reconfigure query sampling.删除或重命名集合时，查询采样会自动禁用。如果要在重新创建或重命名集合后对查询进行采样，则必须重新配置查询采样。

samplesPerSeconds Upper Limit上限

The upper limit for samplesPerSecond is 50. A higher rate causes the sampled queries to fill up 10GB of disk space in less than four days.每秒samplesPerSecond为50。更高的速率会导致采样查询在不到四天的时间内填满10GB的磁盘空间。

This table shows the estimated disk usage for each sample rate and duration combination:此表显示了每种采样率和持续时间组合的估计磁盘使用情况：

queryAnalysisSampleExpirationSecs

Sampled queries are stored in an internal collection that has a TTL index with expireAfterSeconds. To configure expireAfterSeconds, use the queryAnalysisSampleExpirationSecs server parameter. Sampled queries are automatically deleted after queryAnalysisSampleExpirationSecs.采样查询存储在一个内部集合中，该集合的TTL索引为expireAfterSeconds。要配置expireAfterSeconds，请使用queryAnalysisSampleExpirationSecs服务器参数。在queryAnalysisSampleExpirationSecs之后，采样查询会自动删除。

Query Sampling Progress查询采样进度

To monitor the query sampling process, use the $currentOp stage. For an example, see Sampled Queries.要监视查询采样过程，请使用$currentOp阶段。有关示例，请参阅采样查询。

View Sampled Queries查看示例查询

To see sampled queries for all collections or a specific collection, use the $listSampledQueries aggregation stage.要查看所有集合或特定集合的采样查询，请使用$listSampledQueries聚合阶段。

To see the count of every command type captured by the query analyzer, use:要查看查询分析器捕获的每种命令类型的计数，请使用：

db.getSiblingDB("admin").aggregate( [
  { "$listSampledQueries": { ns: "<db.collectionName>" } },
  {
    "$group": {
      "_id": {
        ns: "$ns",
        cmdName: "$cmdName"
      },
      count: { "$sum": 1 }
    }
  },
  {
   "$project": {
     "_id.ns": 1,
      "_id.cmdName": 1,
      "count": 1 // Explicitly include fields to output
    }
  },
  { "$sort": { "_id.ns": 1 } }
] );

[{ count: 10, cmdName: 'aggregate' },
  { count: 51, cmdName: 'delete' },
  { count: 25, cmdName: 'distinct' },
  { count: 100, cmdName: 'find' },
  { count: 24, cmdName: 'findAndModify' },
  { count: 7, cmdName: 'update' }]

When you have enough samples, you can disable the query analyzer.当您有足够的样本时，可以禁用查询分析器。

Limitations局限性

• You cannot run configureQueryAnalyzer on Atlas flex clusters.您无法在Atlas flex集群上运行configureQueryAnalyzer。
• You cannot run configureQueryAnalyzer on standalone deployments.您无法在独立部署上运行configureQueryAnalyzer。
• You cannot run configureQueryAnalyzer directly against a --shardsvr replica set. 您不能直接对--shardsvr副本集运行configureQueryAnalyzer。When running on a sharded cluster, configureQueryAnalyzer must run against a mongos.在分片集群上运行时，configureQueryAnalyzer必须针对mongos运行。
• You cannot run configureQueryAnalyzer against time series collections.您无法对时间序列集合运行configureQueryAnalyzer。
• You cannot run configureQueryAnalyzer against collections with Queryable Encryption.您无法对具有可查询加密的集合运行configureQueryAnalyzer。

Enable Query Sampling启用查询采样

To enable query sampling on the test.students collection at a rate of five samples per second, use the following command:要以每秒五个样本的速度对test.students集合启用查询采样，请使用以下命令：

db.adminCommand(
   {
     configureQueryAnalyzer: "test.students",
     mode: "full",
     samplesPerSecond: 5
   }
)

Disable Query Sampling禁用查询采样

To disable query sampling on the test.students collection, use the following command:要禁用test.students集合上的查询采样，请使用以下命令：

db.adminCommand(
   {
     configureQueryAnalyzer: "test.students",
     mode: "off"
   }
)