[DOC-11724] Update the metics (execution time) parameter (#629)

Author: rakhi-prathap

modules/n1ql/pages/n1ql-language-reference/n1ql-auditing.adoc

@@ -130,7 +130,10 @@ The syslog format will allow for integration with third party SIEM tools, such a
 | `success`
 
 | `metrics`
-| The elapsed time (ms), execution time (ms), result count, and result size (MB).
+| The elapsed time (ms), execution time, result count, and result size (MB).
+
+The execution time can be in milliseconds (ms), microseconds (µs), or nanoseconds (ns), depending on the duration of the query.
+To determine the unit, check the suffix of each value.
 | `"elapsedTime":"7.599684ms",`
 
 `"executionTime":"7.507755ms",`