(DOCSP-4806) Create a new Sampling page (#239)

* Creating Sampling page, updated refs

* Sampling page

* Wrap at 72

* Updates from copy review

* Move Sampling page to bottom of ToC

Author: zach-carr

source/faq.txt

@@ -24,12 +24,6 @@ Testing has shown that |compass| has minimal impact in prototype
 deployments, though additional performance testing and monitoring is in
 progress.
 
-For best results, use MongoDB 3.2 or higher, which includes the
-:manual:`$sample </reference/operator/aggregation/sample/>` operator for
-efficient sampling on a collection. On older versions of MongoDB,
-|compass| falls back on a
-:ref:`less efficient sampling method <compass_fallback_sampling>`.
-
 You should only execute queries that are indexed appropriately in the
 database to avoid scanning the entire collection.
 
@@ -64,63 +58,6 @@ Why am I seeing a warning about a non-genuine MongoDB server?
 
 .. include:: /includes/fact-non-genuine-warning.rst
 
-.. _compass-faq-sampling:
-
-What is sampling and why is it used?
-------------------------------------
-
-Sampling in |compass| is the selection a subset of data
-from a particular collection and analyzing the documents within the
-sample set.
-
-Sampling is a common technique in statistical analysis because analyzing
-a subset of the data gives similar results to analyzing all of it. In
-addition, sampling allows results to be generated quickly rather than
-performing a computationally-expensive collection scan.
-
-How does sampling work?
------------------------
-
-|compass| employs two distinct sampling mechanisms.
-
-In MongoDB 3.2, collections are sampled with the
-:manual:`$sample </reference/operator/aggregation/sample/>` operator via
-the :manual:`aggregation pipeline </core/aggregation-pipeline>`. This
-provides efficient random sampling without replacement over the entire
-collection, or over the subset of documents specified by a query.
-
-.. _compass_fallback_sampling:
-
-In MongoDB 3.0, collections are sampled via a
-backwards-compatible algorithm executed entirely within |compass|. It
-takes place in three stages:
-
-1. |compass| opens a :term:`cursor` on the desired collection, limited
-   to at most 10,000 documents sorted in descending order of the ``_id``
-   field.
-2. ``sampleSize`` documents are randomly selected from the stream. To
-   do this efficiently, |compass| employs `reservoir sampling
-   <http://en.wikipedia.org/wiki/Reservoir_sampling>`_.
-3. |compass| performs a query to select the chosen documents directly
-   via ``_id``.
-
-``sampleSize`` is set to 1000 documents.
-
-.. note::
-  The choice of sampling method is done transparently in the
-  background, with no changes required by the user.
-
-Won't sampling miss documents?
-------------------------------
-
-Sampling is chosen for its efficiency: the amount of time required to
-perform a sample is minimal, on the order of a few seconds. Increasing
-the sample confidence will demand more processing power and time.
-Furthermore, sophisticated outlier detection requires an inspection of
-every document in a MongoDB deployment, which would be unfeasible for
-large data sets. The MongoDB team is in the process of conducting user
-tests on large data sets to find a reasonable balance.
-
 What happens to long running queries?
 -------------------------------------
 
@@ -133,9 +70,9 @@ Slow Sampling
 All queries that Compass sends to your MongoDB instance have a timeout
 flag set which automatically aborts a request if it takes longer than
 the specified timeout. This timeout is currently set to 10 seconds. If
-sampling on the database takes longer, Compass will notify you about
-the timeout and give you the options of (a) retrying with a longer
-timeout (60 seconds) or (b) running a different query.
+:ref:`sampling <sampling>` on the database takes longer, Compass will 
+notify you about the timeout and give you the options of (a) retrying 
+with a longer timeout (60 seconds) or (b) running a different query.
 
 .. note::
 

source/includes/extracts-query-bar.yaml

@@ -4,7 +4,7 @@ content: |
    shows a sampling of the results.  Otherwise, Compass
    shows the entire result set.
    
-   For details on sampling, see the :ref:`FAQ <compass-faq-sampling>`. 
+   For details on sampling, see :ref:`Sampling <sampling>`.
 ---
 ref: query-bar-type-schema
 content: |

source/includes/toc-manage-data.yaml

@@ -34,4 +34,9 @@ file: /validation
 description: |
   Learn how to ensure that all documents in a collection
   follow a defined set of rules.
+---
+file: /sampling
+description: |
+  Learn how |compass-short| samples documents to provide 
+  insights about a collection.
 ...

source/manage-data.txt

@@ -19,3 +19,4 @@ Interact with Your Data
       /indexes
       /schema
       /validation
+      /sampling

source/sampling.txt

@@ -0,0 +1,27 @@
+.. _sampling:
+
+========
+Sampling
+========
+
+.. default-domain:: mongodb
+
+Sampling in |compass| is the selection of a subset of documents from a 
+collection for analysis. Analyzing a sample set of data is a common 
+statistical analysis technique; the results of analyzing a sample set 
+tend to be similar to the results of analyzing an entire data set.
+
+|compass-short| uses sampling for efficiency. Generally, standard 
+sample sets can be selected and analyzed in a few seconds. Analyzing 
+large samples or entire collections demands significantly more time and 
+processing power.
+
+Sampling Method
+---------------
+
+|compass| samples 1,000 documents from a collection using the 
+:manual:`$sample </reference/operator/aggregation/sample/>` 
+operator via the 
+:manual:`aggregation pipeline </core/aggregation-pipeline>`. This 
+provides efficient, random sampling without replacement over an entire 
+collection, or over the subset of documents specified by a query.

source/schema.txt

@@ -21,7 +21,7 @@ The :guilabel:`Schema` tab provides an overview of the data type
 and shape of the fields in a particular collection. Databases
 and collections are visible in the left-side navigation.
 
-The overview is based on :ref:`sampling <compass-faq-sampling>`
+The overview is based on :ref:`sampling <sampling>`
 the documents in the collection. The schema overview may include
 additional data about the contents of the fields, such as the
 minimum and maximum values of dates and integers, the frequency of