DOCS-775 limit on multiple expressions

source/includes/fact-limits-multiple-in-expressions.rst

@@ -0,0 +1,4 @@
+When using two or more :operator:`$in` expressions, the product of the
+number of **distinct** elements in the :operator:`$in` arrays must be
+less than 4000000. Otherwise, MongoDB will throw an exception of
+``"combinatorial limit of $in partitioning of result set exceeded"``.

source/reference/limits.txt

@@ -177,6 +177,11 @@ Operations
 
    .. include:: /includes/fact-geometry-hemisphere-limitation.rst
 
+.. _limit-multiple-in:
+.. limit:: Combination Limit with Multiple $in Expressions
+
+   .. include:: /includes/fact-limits-multiple-in-expressions.rst
+
 Naming Restrictions
 ~~~~~~~~~~~~~~~~~~~
 

source/reference/operator/in.txt

@@ -11,9 +11,9 @@ $in
    :operator:`$in` selects the documents where the ``field`` value
    equals any value in the specified array (e.g. ``<value1>``,
    ``<value2>``, etc.)
-   
+
    Consider the following example: 
-   
+
    .. code-block:: javascript
 
       db.inventory.find( { qty: { $in: [ 5, 15 ] } } )
@@ -24,23 +24,30 @@ $in
    :operator:`$or` operator, choose the :operator:`$in` operator rather
    than the :operator:`$or` operator when performing equality checks on
    the same field.
-   
+
    If the ``field`` holds an array, then the :operator:`$in` operator
    selects the documents whose ``field`` holds an array that contains
    at least one element that matches a value in the specified array
    (e.g. ``<value1>``, ``<value2>``, etc.)
-   
+
    Consider the following example:
-   
+
    .. code-block:: javascript
 
-      db.inventory.update( { tags: { $in: ["appliances", "school"] } }, { $set: { sale:true } } )
-
+      db.inventory.update(
+                           { tags: { $in: ["appliances", "school"] } },
+                           { $set: { sale:true } } 
+                         )
+
    This :method:`update() <db.collection.update()>` operation will set
    the ``sale`` field value in the ``inventory`` collection where the
    ``tags`` field holds an array with at least one element matching an
    element in the array ``["appliances", "school"]``.
-
+
+   .. note::
+
+      .. include:: /includes/fact-limits-multiple-in-expressions.rst
+
    .. seealso::
 
       :method:`find() <db.collection.find()>`, :method:`update()