DOCS-15307 sort order arrays (#1107)

* DOCS-15307-sort-order-arrays

* DOCS-15307-sort-order-arrays

* DOCS-15307-sort-order-arrays

* DOCS-15307-sort-order-arrays

* DOCS-15307-sort-order-arrays

Co-authored-by: jason-price-mongodb <[email protected]>

Author: jason-price-mongodb

source/includes/sorting-arrays.rst

@@ -0,0 +1,14 @@
+In array comparisons:
+
+- A less-than comparison or descending sort compares the smallest
+  elements of the array according to the BSON type sort order.
+
+- A greater-than comparison or descending sort compares the largest
+  elements of the array according to the reverse BSON type sort order.
+
+- When comparing a field whose value is a one element array (example,
+  ``[ 1 ]``) with non-array fields (example, ``2``), the comparison is
+  for ``1`` and ``2``.
+
+- A comparison of an empty array (example, ``[ ]``) considers the empty
+  array as less than a ``null`` value or a missing field value.

source/reference/bson-type-comparison-order.txt

@@ -44,16 +44,12 @@ Collation specification has the following syntax:
 
 .. include:: /includes/extracts/collation-unspecified.rst
 
+.. _bson-type-comparison-order-arrays:
+
 Arrays
 ------
 
-With arrays, a less-than comparison or an ascending sort compares the
-smallest element of arrays, and a greater-than comparison or a
-descending sort compares the largest element of the arrays. As such,
-when comparing a field whose value is a single-element array (e.g. ``[
-1 ]``) with non-array fields (e.g. ``2``), the comparison is between
-``1`` and ``2``. A comparison of an empty array (e.g. ``[ ]``) treats
-the empty array as less than ``null`` or a missing field.
+.. include:: /includes/sorting-arrays.rst
 
 Objects
 -------

source/tutorial/sort-results-with-indexes.txt

@@ -224,8 +224,8 @@ key field.
 - When an index has a key with multiple data types, the index is
   sorted according to the :ref:`BSON type sort order
   <bson-types-comparison-order>`.
-- If an index key contains an array, the document is sorted according
-  to the type of the first array element.
+
+- .. include:: /includes/sorting-arrays.rst
 
 See the :ref:`index sorting example <ex-sort-index-types>`.
 
@@ -377,8 +377,7 @@ The documents are returned in :ref:`BSON type sort order
      type: 'Timestamp'
    }
 
-- Arrays are sorted according to the type of the first element. In this
-  example the first element types are: Int32, String, and Array. 
+- .. include:: /includes/sorting-arrays.rst
 - Numerical types (Int32, Long, Decimal128, Double) are equivalent when
   compared with other types. 
 - Within the Numbers BSON type, numerical types are sorted: