CTAS table

Author: XiaoyuMSFT

docs/t-sql/statements/create-table-as-select-azure-sql-data-warehouse.md

@@ -40,7 +40,8 @@ CREATE TABLE { database_name.schema_name.table_name | schema_name.table_name | t
       <distribution_option> -- required
       [ , <table_option> [ ,...n ] ]    
     )  
-    AS <select_statement>   
+    AS <select_statement>  
+    OPTION <query_hint> 
 [;]  
 
 <distribution_option> ::=
@@ -53,16 +54,21 @@ CREATE TABLE { database_name.schema_name.table_name | schema_name.table_name | t
 <table_option> ::= 
     {   
         CLUSTERED COLUMNSTORE INDEX --default for SQL Data Warehouse 
+      | CLUSTERED COLUMNSTORE INDEX ORDER (column[,...n])
       | HEAP --default for Parallel Data Warehouse   
       | CLUSTERED INDEX ( { index_column_name [ ASC | DESC ] } [ ,...n ] ) --default is ASC 
     }  
-    | PARTITION ( partition_column_name RANGE [ LEFT | RIGHT ] --default is LEFT  
+      | PARTITION ( partition_column_name RANGE [ LEFT | RIGHT ] --default is LEFT  
         FOR VALUES ( [ boundary_value [,...n] ] ) ) 
   
 <select_statement> ::=  
     [ WITH <common_table_expression> [ ,...n ] ]  
     SELECT select_criteria  
 
+<query_hint> ::=
+    {
+        MAXDOP 
+    }
 ```  
 
 <a name="arguments-bk"></a>
@@ -96,15 +102,19 @@ For details, see the [Table partition options](https://msdn.microsoft.com/librar
 
 <a name="select-options-bk"></a>
 
-### Select options
+### Select statement
 The select statement is the fundamental difference between CTAS and CREATE TABLE.  
 
  `WITH` *common_table_expression*  
  Specifies a temporary named result set, known as a common table expression (CTE). For more information, see [WITH common_table_expression &#40;Transact-SQL&#41;](../../t-sql/queries/with-common-table-expression-transact-sql.md).  
 
  `SELECT` *select_criteria*  
  Populates the new table with the results from a SELECT statement. *select_criteria* is the body of the SELECT statement that determines which data to copy to the new table. For information about SELECT statements, see [SELECT &#40;Transact-SQL&#41;](../../t-sql/queries/select-transact-sql.md).  
-  
+ 
+### Query hint
+Users can set MAXDOP to an integer value to control the maximum degree of parallelism.  When MAXDOP is set to 1, the query is executed by a single thread.
+
+ 
 <a name="permissions-bk"></a>  
 
 ## Permissions  
@@ -814,6 +824,14 @@ OPTION (LABEL = 'CTAS : Partition IN table : Create');
 ```
 
 You can see therefore that type consistency and maintaining nullability properties on a CTAS is a good engineering best practice. It helps to maintain integrity in your calculations and also ensures that partition switching is possible.
+
+### N. Create an ordered clustered columnstore index with MAXDOP 1  
+```sql
+CREATE TABLE Table1 WITH (DISTRIBUTION = HASH(c1), CLUSTERED COLUMNSTORE INDEX ORDER(c1) )
+AS SELECT * FROM ExampleTable
+OPTION (MAXDOP 1);
+```
+
 
 ## See Also  
  [CREATE EXTERNAL DATA SOURCE &#40;Transact-SQL&#41;](../../t-sql/statements/create-external-data-source-transact-sql.md)