DOCS-902 adding notes about $or operator and 2d geo queries

Author: Sam Kleinman

source/reference/limits.txt

@@ -93,7 +93,7 @@ Indexes
    .. see:: :doc:`/tutorial/enforce-unique-keys-for-sharded-collections`
       for an alternate approach.
 
-.. limit:: Number of Indexed Fields in a Compound Index:
+.. limit:: Number of Indexed Fields in a Compound Index
 
    There can be no more than 31 fields in a compound index.
 
@@ -137,6 +137,10 @@ Operations
 
    :operator:`$snapshot` queries do not work in sharded environments.
 
+.. limit:: 2d Geospatial queries cannot use the $or operator
+
+   .. see:: :operator:`$or` and :doc:`/core/geospatial-indexes`.
+
 Naming Restrictions
 ~~~~~~~~~~~~~~~~~~~
 
@@ -178,12 +182,10 @@ Naming Restrictions
    See :ref:`faq-restrictions-on-collection-names` and
    :ref:`rn-2.2-collection-name-restriction` for more information.
 
-.. _limit-restrictions-on-field-names: 
+.. _limit-restrictions-on-field-names:
 
 .. limit:: Restrictions on Field Names
 
    Field names cannot contain dots (i.e. ``.``), dollar signs
    (i.e. ``$``), or null characters. See
    :ref:`faq-dollar-sign-escaping` for an alternate approach.
-   
-   

source/reference/operator/or.txt

@@ -19,54 +19,54 @@ $or
    *at least* one of the ``<expressions>``.
 
    Consider the following query:
-   
+
    .. code-block:: javascript
-        
+
       db.inventory.find( { price:1.99, $or: [ { qty: { $lt: 20 } }, { sale: true } ] } )
-			
+
    This query will select all documents in the ``inventory`` collection
    where:
-   
-   - the ``price`` field value equals ``1.99`` *and*    
+
+   - the ``price`` field value equals ``1.99`` *and*
    - either the ``qty`` field value is less than ``20`` **or** the
      ``sale`` field value is ``true``.
-   
+
    Consider the following example which uses the :operator:`$or` operator to select
    fields from embedded documents:
 
    .. code-block:: javascript
- 
+
       db.inventory.update( { $or: [ { price:10.99 }, { "carrier.state": "NY"} ] }, { $set: { sale: true } } )
-   
+
    This :method:`update() <db.collection.update()>` operation will set
    the value of the ``sale`` field in the documents in the
    ``inventory`` collection where:
-   
-   - the ``price`` field value equals ``10.99`` **or**   
+
+   - the ``price`` field value equals ``10.99`` **or**
    - the ``carrier`` embedded document contains a field ``state`` whose
      value equals ``NY``.
-    
+
    When using :operator:`$or` with ``<expressions>`` that are equality
    checks for the value of the same field, choose the :operator:`$in`
    operator over the :operator:`$or` operator.
-   
+
    Consider the query to select all documents in the ``inventory``
    collection where:
-   
+
    - either ``price`` field value equals ``1.99`` *or* the ``sale``
      field value equals ``true``, **and**
    - either ``qty`` field value equals ``20`` *or* ``qty`` field value
      equals ``50``,
-   
+
    The most effective query would be:
-   
+
    .. code-block:: javascript
-  
+
       db.inventory.find ( { $or: [ { price: 1.99 }, { sale: true } ], qty: { $in: [20, 50] } } )
 
    Consider the following behaviors when using the :operator:`$or`
    operator:
-   
+
    - When using indexes with :operator:`$or` queries, remember that
      each clause of an :operator:`$or` query will execute in parallel.
      These clauses can each use their own index. Consider the following
@@ -93,6 +93,9 @@ $or
      This modified query will not use the index on ``price`` nor the
      index on ``sale``.
 
+   - You cannot use the :operator:`$or` with ``2d`` :doc:`geospatial
+     queries </core/geospatial-indexes>`.
+
    .. seealso:: :method:`find() <db.collection.find()>`,
       :method:`update() <db.collection.update()>`, :operator:`$set`,
       :operator:`$and`, :method:`sort() <cursor.sort()>`.