Configure the Slow Query Threshold
The Performance Advisor recognizes a query as slow if it takes longer
to execute than the value of
slowOpThresholdMs.
By default, this value is 100 milliseconds. You can change the
threshold with either the
profile
command or the db.setProfilingLevel()
mongosh method.
Example
The following profile command example sets the threshold at 200
milliseconds:
db.runCommand({ profile: 0, slowOpThresholdMs: 200 })
If you are running MongoDB 3.6 or later, you can customize the
percentage of slow queries in your logs used by the Performance Advisor
by specifying the sampleRate parameter.
Example
This sets the slow query threshold to a lower value of 100 milliseconds but also sets the sample rate to 10%.
db.runCommand({ profile: 0, slowOpThresholdMs: 100, sampleRate: 0.1 })
Note
By default, the value of profile is 0. MongoDB recommends
leaving this value unchanged since other values can negatively
impact database performance. To learn more, see the
profile command.