sampleRate is global

sampleRate is global, just as slowms so changing the wording to make it clear.

Author: asya999

source/tutorial/manage-the-database-profiler.txt

@@ -122,8 +122,8 @@ Profile a Random Sample of Slow Operations
 
 .. versionadded:: 3.6
 
-To profile only a randomly sampled subset of all *slow* operations on a
-specific database, specify the desired sample rate in one of the following ways:
+To profile only a randomly sampled subset of all *slow* operations, specify the
+desired sample rate in one of the following ways:
 
 - Set the value of ``sampleRate`` using the :dbcommand:`profile` command
   or :method:`db.setProfilingLevel()` shell helper method.
@@ -135,9 +135,9 @@ specific database, specify the desired sample rate in one of the following ways:
   :ref:`configuration file <configuration-options>`.
 
 By default, ``sampleRate`` is set to ``1.0``, meaning all *slow*
-operations are profiled. Databases with a ``sampleRate`` between 0 and 1
-will only profile a randomly sampled percentage of *slow* operations
-according to ``sampleRate``.
+operations are profiled. When ``sampleRate`` is set between 0 and 1  
+databases with profiling level ``1`` will only profile a randomly sampled 
+percentage of *slow* operations according to ``sampleRate``.
 
 For example, the following method sets the profiling level for the
 current database to ``1`` and sets the profiler to sample 42% of all *slow* operations:
@@ -146,6 +146,11 @@ current database to ``1`` and sets the profiler to sample 42% of all *slow* oper
 
    db.setProfilingLevel(1, { sampleRate: 0.42 })
 
+.. important::
+   The sample rate value applies to all databases in a
+   :binary:`~bin.mongod` instance. It is used by both the database profiler
+   and the system log
+   
 .. important::
    .. include:: /includes/fact-log-slow-queries.rst