Merge pull request #110972 from timsander1/master

update distinct and Group By limitation

Author: PRMerger7

articles/cosmos-db/sql-query-group-by.md

@@ -4,7 +4,7 @@ description: Learn about the GROUP BY clause for Azure Cosmos DB.
 author: timsander1
 ms.service: cosmos-db
 ms.topic: conceptual
-ms.date: 10/11/2019
+ms.date: 04/10/2020
 ms.author: tisande
 
 ---
@@ -48,6 +48,12 @@ The GROUP BY clause divides the query's results according to the values of one o
 - Subqueries
 - Aggregate system functions (these are only allowed in the SELECT clause)
 
+Queries with an aggregate system function and a subquery with `GROUP BY` are not supported. For example, the following query is not supported:
+
+```sql
+SELECT COUNT(UniqueLastNames) FROM (SELECT AVG(f.age) FROM f GROUP BY f.lastName) AS UniqueLastNames
+```
+
 ## Examples
 
 These examples use the nutrition data set available through the [Azure Cosmos DB Query Playground](https://www.documentdb.com/sql/demo).

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

@@ -1,11 +1,11 @@
 ---
 title: SQL keywords for Azure Cosmos DB
 description: Learn about SQL keywords for Azure Cosmos DB.
-author: markjbrown
+author: timsander1
 ms.service: cosmos-db
 ms.topic: conceptual
-ms.date: 03/17/2020
-ms.author: mjbrown
+ms.date: 04/10/2020
+ms.author: tisande
 
 ---
 # Keywords in Azure Cosmos DB