From 5b7c5d85297977f62a2fed0e243283f2ba20f426 Mon Sep 17 00:00:00 2001
From: kay <kay.kim@10gen.com>
Date: Mon, 22 Apr 2013 15:04:19 -0400
Subject: [PATCH] DOCS-775 limit on multiple  expressions

---
 .../fact-limits-multiple-in-expressions.rst   |  4 ++++
 source/reference/limits.txt                   |  5 ++++
 source/reference/operator/in.txt              | 23 ++++++++++++-------
 3 files changed, 24 insertions(+), 8 deletions(-)
 create mode 100644 source/includes/fact-limits-multiple-in-expressions.rst

diff --git a/source/includes/fact-limits-multiple-in-expressions.rst b/source/includes/fact-limits-multiple-in-expressions.rst
new file mode 100644
index 00000000000..1d7cdb99796
--- /dev/null
+++ b/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"``.
diff --git a/source/reference/limits.txt b/source/reference/limits.txt
index 35e2645c2ec..551462a0e65 100644
--- a/source/reference/limits.txt
+++ b/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
 ~~~~~~~~~~~~~~~~~~~
 
diff --git a/source/reference/operator/in.txt b/source/reference/operator/in.txt
index 0cbd65f7afc..1a608b3bc41 100644
--- a/source/reference/operator/in.txt
+++ b/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()