DOCS-617 crud draft fix typos

Author: kay-kim

draft/core/documents.txt

@@ -64,7 +64,7 @@ Consider the following examples of MongoDB documents:
        { _id: 1 }
 
   - The following document specifies the query criteria where ``_id``
-    is greater to ``3``:
+    is greater than ``3``:
 
     .. code-block:: javascript
 
@@ -80,14 +80,15 @@ Consider the following examples of MongoDB documents:
 
   When passed as an argument to methods such as the :method:`find()
   <db.collection.find()>` method or the :method:`update()
-  <db.collection.update()>` method, the query document limits the
-  records returned or updated:
+  <db.collection.update()>` method, the query document determines which
+  records are returned or updated:
 
   .. code-block:: javascript
 
      db.csbios.find( { _id: 1 } )
      db.csbios.find( { _id: { $gt: 3 } } )
-     db.csbios.find( { _id: 1, name: { first: 'John', last: 'Backus' } } )
+     db.csbios.update( { _id: 1, name: { first: 'John', last: 'Backus' } }, 
+                       ... )
 
 - The following document specifies the update actions:
 
@@ -115,25 +116,25 @@ Consider the following examples of MongoDB documents:
 
   .. code-block:: javascript
 
-     {  'name.last': 1  }
+     { 'name.last': 1, 'name.first':1  }
 
   When passed as an argument to the :method:`sort() <cursor.sort()>`
   method, the document specifies the sort order of the results:
 
   .. code-block:: javascript
 
-     db.csbios.find().sort( { 'name.last': 1 } )
+     db.csbios.find().sort( { 'name.last': 1, 'name.first': 1 } )
 
-- The following document specifies the index to create:
+- The following document specifies the multi-key index to create:
 
   .. code-block:: javascript
 
-     {  id:1, 'name.last': 1 }
+     { _id:1, 'name.last': 1 }
 
   When passed as an argument to the :method:`ensureIndex()
   <db.collection.ensureIndex()>` method, the document specifies the
   multi-key index to create on the fields ``_id`` and ``name.last``:
 
   .. code-block:: javascript
 
-     db.csbios.ensureIndex( {  id:1, 'name.last': 1 } )
+     db.csbios.ensureIndex( { _id: 1, 'name.last': 1 } )

draft/core/read-operations.txt

@@ -86,6 +86,13 @@ Consider the ``query`` arguments in the following :method:`find()
 
      db.inventory.find( { type: { $in: [ 'food', 'snacks' ] } } )
 
+  .. note::
+
+     Although you can express this query using the :operator:`$or`
+     operator, choose the :operator:`$in` operator rather than the
+     :operator:`$or` operator when performing equality checks on the
+     same field.
+
 - Compound ``query`` argument specifies the criteria where the field
   ``type`` equals ``food`` **and** the field ``price`` is less than
   ``9.95``: