Merge pull request #106784 from timsander1/master

update info about optimizations to limit cross partition queries

Author: PRMerger8

articles/cosmos-db/sql-query-aggregates.md

@@ -1,11 +1,11 @@
 ---
 title: Aggregate functions in Azure Cosmos DB
 description: Learn about SQL aggregate function syntax, types of aggregate functions supported by Azure Cosmos DB.
-author: markjbrown
+author: timsander1
 ms.service: cosmos-db
 ms.topic: conceptual
-ms.date: 12/02/2019
-ms.author: mjbrown
+ms.date: 03/05/2020
+ms.author: tisande
 
 ---
 # Aggregate functions in Azure Cosmos DB

articles/cosmos-db/sql-query-keywords.md

@@ -103,7 +103,7 @@ Queries with an aggregate system function and a subquery with DISTINCT are not s
 SELECT COUNT(1) FROM (SELECT DISTINCT f.lastName FROM f)
 ```
 
-## <a name="in"></a> IN
+## IN
 
 Use the IN keyword to check whether a specified value matches any value in a list. For example, the following query returns all family items where the `id` is `WakefieldFamily` or `AndersenFamily`.
 
@@ -121,7 +121,9 @@ The following example returns all items where the state is any of the specified
     WHERE Families.address.state IN ("NY", "WA", "CA", "PA", "OH", "OR", "MI", "WI", "MN", "FL")
 ```
 
-The SQL API provides support for [iterating over JSON arrays](sql-query-object-array.md#Iteration), with a new construct added via the in keyword in the FROM source. 
+The SQL API provides support for [iterating over JSON arrays](sql-query-object-array.md#Iteration), with a new construct added via the in keyword in the FROM source.
+
+If you include your partition key in the `IN` filter, your query will automatically filter to only the relevant partitions.
 
 ## TOP
 

articles/cosmos-db/sql-query-where.md

@@ -4,7 +4,7 @@ description: Learn about SQL WHERE clause for Azure Cosmos DB
 author: timsander1
 ms.service: cosmos-db
 ms.topic: conceptual
-ms.date: 02/03/2020
+ms.date: 03/06/2020
 ms.author: tisande
 
 ---
@@ -30,10 +30,11 @@ WHERE <filter_condition>
 
    Expression representing the value to be computed. See [Scalar expressions](sql-query-scalar-expressions.md) for details.  
 
-
 ## Remarks
 
-  In order for the document to be returned an expression specified as filter condition must evaluate to true. Only Boolean value true will satisfy the condition, any other value: undefined, null, false, Number, Array, or Object will not satisfy the condition. 
+  In order for the document to be returned an expression specified as filter condition must evaluate to true. Only Boolean value `true` will satisfy the condition, any other value: undefined, null, false, Number, Array, or Object will not satisfy the condition.
+
+  If you include your partition key in the `WHERE` clause as part of an equality filter, your query will automatically filter to only the relevant partitions.
 
 ## Examples