Merge pull request #96935 from ronortloff/WLMUpdates

Update what-is-a-data-warehouse-unit-dwu-cdwu.md

Author: GitHubber17

articles/sql-data-warehouse/what-is-a-data-warehouse-unit-dwu-cdwu.md

@@ -1,25 +1,25 @@
 ---
-title: Data Warehouse Units (DWUs, cDWUs) in Azure Synapse Analytics (formerly SQL DW) 
-description: Recommendations on choosing the ideal number of data warehouse units (DWUs, cDWUs) to optimize price and performance, and how to change the number of units.
+title: Data Warehouse Units (DWUs) in Azure Synapse Analytics (formerly SQL DW) 
+description: Recommendations on choosing the ideal number of data warehouse units (DWUs) to optimize price and performance, and how to change the number of units.
 services: sql-data-warehouse
 author: mlee3gsd
 manager: craigg
 ms.service: sql-data-warehouse
 ms.topic: conceptual
 ms.subservice: design
-ms.date: 11/04/2019
+ms.date: 11/22/2019
 ms.author: martinle
 ms.reviewer: igorstan
 ms.custom: seo-lt-2019
 ---
 
-# Data Warehouse Units (DWUs) and compute Data Warehouse Units (cDWUs)
+# Data Warehouse Units (DWUs)
 
-Recommendations on choosing the ideal number of data warehouse units (DWUs, cDWUs) to optimize price and performance, and how to change the number of units.
+Recommendations on choosing the ideal number of data warehouse units (DWUs) to optimize price and performance, and how to change the number of units.
 
 ## What are Data Warehouse Units
 
-SQL pool represents a collection of analytic resources that are being provisioned when using [SQL Analytics](sql-data-warehouse-overview-what-is.md#sql-analytics-and-sql-pool-in-azure-synapse). Analytic resources are defined as a combination of CPU, memory and IO. These three resources are bundled into units of compute scale called Data Warehouse Units (DWUs). A DWU represents an abstract, normalized measure of compute resources and performance. A change to your service level alters the number of DWUs that are available to the system, which in turn adjusts the performance, and the cost, of your system.
+A [SQL pool](sql-data-warehouse-overview-what-is.md#sql-analytics-and-sql-pool-in-azure-synapse) represents a collection of analytic resources that are being provisioned when using [SQL Analytics](sql-data-warehouse-overview-what-is.md#sql-analytics-and-sql-pool-in-azure-synapse). Analytic resources are defined as a combination of CPU, memory and IO. These three resources are bundled into units of compute scale called Data Warehouse Units (DWUs). A DWU represents an abstract, normalized measure of compute resources and performance. A change to your service level alters the number of DWUs that are available to the system, which in turn adjusts the performance, and the cost, of your system.
 
 For higher performance, you can increase the number of data warehouse units. For less performance, reduce data warehouse units. Storage and compute costs are billed separately, so changing data warehouse units does not affect storage costs.
 
@@ -37,40 +37,19 @@ Increasing DWUs:
 
 ## Service Level Objective
 
-The Service Level Objective (SLO) is the scalability setting that determines the cost and performance level of your data warehouse. The service levels for Gen2 SQL pool are measured in compute data warehouse units (cDWU), for example DW2000c. Gen1 SQL pool service levels are measured in DWUs, for example DW2000.
-  > [!NOTE]
-  > Gen 2 SQL pool recently added additional scale capabilities to support compute tiers as low as 100 cDWU. Existing SQL pools currently on Gen1 that require the lower compute tiers can now upgrade to Gen2 in the regions that are currently available for no additional cost.  If your region is not yet supported, you can still upgrade to a supported region. For more information, see [Upgrade to Gen2](upgrade-to-latest-generation.md).
+The Service Level Objective (SLO) is the scalability setting that determines the cost and performance level of your data warehouse. The service levels for Gen2 SQL pool are measured in data warehouse units (DWU), for example DW2000c.
 
-In T-SQL, the SERVICE_OBJECTIVE setting determines the service level and the performance tier for your SQL pool.
+In T-SQL, the SERVICE_OBJECTIVE setting determines the service level for your SQL pool.
 
 ```sql
---Gen1
-CREATE DATABASE myElasticSQLDW
-WITH
-(    SERVICE_OBJECTIVE = 'DW1000'
-)
-;
-
---Gen2
-CREATE DATABASE myComputeSQLDW
-(Edition = 'Datawarehouse'
+CREATE DATABASE mySQLDW
+( EDITION = 'Datawarehouse'
  ,SERVICE_OBJECTIVE = 'DW1000c'
 )
 ;
 ```
 
-## Performance Tiers and Data Warehouse Units
-
-Each performance tier uses a slightly different unit of measure for their data warehouse units. This difference is reflected on the invoice as the unit of scale directly translates to billing.
-
-- Gen1 SQL pools are measured in Data Warehouse Units (DWUs).
-- Gen2 SQL pools are measured in compute Data Warehouse Units (cDWUs).
-
-Both DWUs and cDWUs support scaling compute up or down, and pausing compute when you don't need to use the SQL pool. These operations are all on-demand. Gen2 uses a local disk-based cache on the compute nodes to improve performance. When you scale or pause the system, the cache is invalidated and so a period of cache warming is required before optimal performance is achieved.  
-
-As you increase data warehouse units, you are linearly increasing computing resources. Gen2 provides the best query performance and highest scale. Gen2 systems also make the most use of the cache.
-
-### Capacity limits
+## Capacity limits
 
 Each SQL server (for example, myserver.database.windows.net) has a [Database Transaction Unit (DTU)](../sql-database/sql-database-what-is-a-dtu.md) quota that allows a specific number of data warehouse units. For more information, see the [workload management capacity limits](sql-data-warehouse-service-capacity-limits.md#workload-management).
 
@@ -117,7 +96,7 @@ JOIN    sys.databases                     AS db ON ds.database_id = db.database_
 
 ### Azure portal
 
-To change DWUs or cDWUs:
+To change DWUs:
 
 1. Open the [Azure portal](https://portal.azure.com), open your database, and click **Scale**.
 
@@ -129,40 +108,40 @@ To change DWUs or cDWUs:
 
 [!INCLUDE [updated-for-az](../../includes/updated-for-az.md)]
 
-To change the DWUs or cDWUs, use the [Set-AzSqlDatabase](/powershell/module/az.sql/set-azsqldatabase) PowerShell cmdlet. The following example sets the service level objective to DW1000 for the database MySQLDW that is hosted on server MyServer.
+To change the DWUs, use the [Set-AzSqlDatabase](/powershell/module/az.sql/set-azsqldatabase) PowerShell cmdlet. The following example sets the service level objective to DW1000c for the database MySQLDW that is hosted on server MyServer.
 
 ```Powershell
-Set-AzSqlDatabase -DatabaseName "MySQLDW" -ServerName "MyServer" -RequestedServiceObjectiveName "DW1000"
+Set-AzSqlDatabase -DatabaseName "MySQLDW" -ServerName "MyServer" -RequestedServiceObjectiveName "DW1000c"
 ```
 
 For more information, see [PowerShell cmdlets for SQL Data Warehouse](sql-data-warehouse-reference-powershell-cmdlets.md)
 
 ### T-SQL
 
-With T-SQL you can view the current DWU or cDWU settings, change the settings, and check the progress.
+With T-SQL you can view the current DWU settings, change the settings, and check the progress.
 
-To change the DWUs or cDWUs:
+To change the DWUs:
 
 1. Connect to the master database associated with your logical SQL Database server.
-2. Use the [ALTER DATABASE](/sql/t-sql/statements/alter-database-transact-sql) TSQL statement. The following example sets the service level objective to DW1000 for the database MySQLDW.
+2. Use the [ALTER DATABASE](/sql/t-sql/statements/alter-database-transact-sql) TSQL statement. The following example sets the service level objective to DW1000c for the database MySQLDW.
 
 ```Sql
 ALTER DATABASE MySQLDW
-MODIFY (SERVICE_OBJECTIVE = 'DW1000')
+MODIFY (SERVICE_OBJECTIVE = 'DW1000c')
 ;
 ```
 
 ### REST APIs
 
-To change the DWUs, use the [Create or Update Database](/rest/api/sql/databases/createorupdate) REST API. The following example sets the service level objective to DW1000 for the database MySQLDW, which is hosted on server MyServer. The server is in an Azure resource group named ResourceGroup1.
+To change the DWUs, use the [Create or Update Database](/rest/api/sql/databases/createorupdate) REST API. The following example sets the service level objective to DW1000c for the database MySQLDW, which is hosted on server MyServer. The server is in an Azure resource group named ResourceGroup1.
 
 ```
 PUT https://management.azure.com/subscriptions/{subscription-id}/resourceGroups/{resource-group-name}/providers/Microsoft.Sql/servers/{server-name}/databases/{database-name}?api-version=2014-04-01-preview HTTP/1.1
 Content-Type: application/json; charset=UTF-8
 
 {
     "properties": {
-        "requestedServiceObjectiveName": DW1000
+        "requestedServiceObjectiveName": DW1000c
     }
 }
 ```