| Version | Change log |
| MongoDB 8.0.0 Sep 23, 2024 |
Logging: Starting in MongoDB 8.0, you can configure the Database Profiler to log slow operations based on the time that MongoDB spends working on that operation, rather than the total latency for the operation. This means that factors such as waiting for locks and flow control do not affect whether an operation exceeds the slow operation threshold. This change provides the following improvements for logging and query analysis: Slow queries are logged more accurately based on the time MongoDB spends processing the query. Query analysis tools such as the Query Profiler, Performance Advisor, and Search Query Telemetry report slow operations based on workingMillis instead of durationMillis. This change provides a more accurate view of problematic queries. Slow query logs include a metric for the time queued on execution tickets, queues.execution.totalTimeQueuedMicros. This metric helps identify whether an operation is slow because of the time it takes to complete, or the time it spends waiting to start. Database Profiler: When you specify a filter for the database profiler, you can log operations based on the new workingMillis metric. You can log operations based on both workingMillis and durationMillis and set each metric to a different threshold. Aggregation: BinData Conversion: Starting in MongoDB 8.0, you can use the $convert operator to perform the following conversions: String values to binData values binData values to string values MongoDB 8.0 also includes a new helper expression, $toUUID, which provides simplified syntax for converting strings to UUID values. $queryStats Change Stream Improvements: Starting in MongoDB 8.0, $queryStats improves tracking and reporting metrics for change streams. For more information, see $queryStats Change Streams Behavior. $rank and $denseRank Behavior: Starting in MongoDB 8.0, null and missing field values in $denseRank and $rank sortBy operations are treated the same when calculating rankings. This change makes the behavior of |
