Optimize performance by upgrading SQL Data Warehouse

Upgrade Azure SQL Data Warehouse to latest generation of Azure hardware and storage architecture.

Why upgrade?

You can now seamlessly upgrade to the SQL Data Warehouse Compute Optimized Gen2 tier in the Azure portal for supported regions. If your region does not support self-upgrade, you can upgrade to a supported region or wait for self-upgrade to be available in your region. Upgrade now to take advantage of the latest generation of Azure hardware and enhanced storage architecture including faster performance, higher scalability, and unlimited columnar storage.

Applies to

This upgrade applies to Compute Optimized Gen1 tier data warehouses in supported regions.

Before you begin

  1. Check if your region is supported for GEN1 to GEN2 migration. Note the automatic migration dates. To avoid conflicts with the automated process, plan your manual migration prior to the automated process start date.
  2. If you are in a region that is not yet supported, continue to check for your region to be added or upgrade using restore to a supported region.
  3. If your region is supported, upgrade through the Azure portal
  4. Select the suggested performance level for the data warehouse based on your current performance level on Compute Optimized Gen1 tier by using the mapping below:

    Compute Optimized Gen1 tier Compute Optimized Gen2 tier
    DW100 DW100c
    DW200 DW200c
    DW300 DW300c
    DW400 DW400c
    DW500 DW500c
    DW600 DW500c
    DW1000 DW1000c
    DW1200 DW1000c
    DW1500 DW1500c
    DW2000 DW2000c
    DW3000 DW3000c
    DW6000 DW6000c

    Note

    Suggested performance levels are not a direct conversion. For example, we recommend going from DW600 to DW500c.

Upgrade in a supported region using the Azure portal

Note

Migration from GEN1 to GEN2 through the Azure portal is permanent. There is not a process for returning to GEN1.

Sign in to the Azure portal

Sign in to the Azure portal.

  1. If the Compute Optimized Gen1 tier data warehouse to be upgraded is paused, resume the data warehouse.

    Note

    Azure SQL Data Warehouse must be running to migrate to Gen2.

  2. Be prepared for a few minutes of downtime.

  3. Identify any code references to Compute Optimized Gen1 performance levels and modify them to their equivalent Compute Optimized Gen2 performance level. Below are two examples of where you should update code references before upgrading:

    Original Gen1 PowerShell command:

    Set-AzureRmSqlDatabase -ResourceGroupName "myResourceGroup" -DatabaseName "mySampleDataWarehouse" -ServerName "mynewserver-20171113" -RequestedServiceObjectiveName "DW300"
    

    Modified to:

    Set-AzureRmSqlDatabase -ResourceGroupName "myResourceGroup" -DatabaseName "mySampleDataWarehouse" -ServerName "mynewserver-20171113" -RequestedServiceObjectiveName "DW300c"
    

    Note

    -RequestedServiceObjectiveName "DW300" is changed to - RequestedServiceObjectiveName "DW300c"

    Original Gen1 T-SQL command:

    ALTER DATABASE mySampleDataWarehouse MODIFY (SERVICE_OBJECTIVE = 'DW300') ;
    

    Modified to:

    ALTER DATABASE mySampleDataWarehouse MODIFY (SERVICE_OBJECTIVE = 'DW300c') ; 
    

    Note

    SERVICE_OBJECTIVE = 'DW300' is changed to SERVICE_OBJECTIVE = 'DW300c'

Start the upgrade

  1. Go to your Compute Optimized Gen1 tier data warehouse in the Azure portal. If the Compute Optimized Gen1 tier data warehouse to be upgraded is paused, resume the data warehouse.
  2. Select Upgrade to Gen2 card under the Tasks tab: Upgrade_1

    Note

    If you do not see the Upgrade to Gen2 card under the Tasks tab, your subscription type is limited in the current region. Submit a support ticket to get your subscription whitelisted.

  3. Ensure your workload has completed running and quiesced before upgrading. You'll experience downtime for a few minutes before your data warehouse is back online as a Compute Optimized Gen2 tier data warehouse. Select Upgrade:

    Upgrade_2

  4. Monitor your upgrade by checking the status in the Azure portal:

    Upgrade3

    The first step of the upgrade process goes through the scale operation ("Upgrading - Offline") where all sessions will be killed, and connections will be dropped.

    The second step of the upgrade process is data migration ("Upgrading - Online"). Data migration is an online trickle background process. This process slowly moves columnar data from the old storage architecture to the new storage architecture using a local SSD cache. During this time, your data warehouse will be online for querying and loading. Your data will be available to query regardless of whether it has been migrated or not. The data migration happens at varying rates depending on your data size, your performance level, and the number of your columnstore segments.

  5. Optional Recommendation: Once the scaling operation is complete, you can speed up the data migration background process. You can force data movement by running Alter Index rebuild on all primary columnstore tables you'd be querying at a larger SLO and resource class. This operation is offline compared to the trickle background process, which can take hours to complete depending on the number and sizes of your tables. However, once complete, data migration will be much quicker due to the new enhanced storage architecture with high-quality rowgroups.

Note

Alter Index rebuild is an offline operation and the tables will not be available until the rebuild completes.

The following query generates the required Alter Index Rebuild commands to expedite data migration:

SELECT 'ALTER INDEX [' + idx.NAME + '] ON [' 
       + Schema_name(tbl.schema_id) + '].[' 
       + Object_name(idx.object_id) + '] REBUILD ' + ( CASE 
                                                         WHEN ( 
                                                     (SELECT Count(*) 
                                                      FROM   sys.partitions 
                                                             part2 
                                                      WHERE  part2.index_id 
                                                             = idx.index_id 
                                                             AND 
                                                     idx.object_id = 
                                                     part2.object_id) 
                                                     > 1 ) THEN 
              ' PARTITION = ' 
              + Cast(part.partition_number AS NVARCHAR(256)) 
              ELSE '' 
                                                       END ) + '; SELECT ''[' + 
              idx.NAME + '] ON [' + Schema_name(tbl.schema_id) + '].[' + 
              Object_name(idx.object_id) + '] ' + ( 
              CASE 
                WHEN ( (SELECT Count(*) 
                        FROM   sys.partitions 
                               part2 
                        WHERE 
                     part2.index_id = 
                     idx.index_id 
                     AND idx.object_id 
                         = part2.object_id) > 1 ) THEN 
              ' PARTITION = ' 
              + Cast(part.partition_number AS NVARCHAR(256)) 
              + ' completed'';' 
              ELSE ' completed'';' 
                                                    END ) 
FROM   sys.indexes idx 
       INNER JOIN sys.tables tbl 
               ON idx.object_id = tbl.object_id 
       LEFT OUTER JOIN sys.partitions part 
                    ON idx.index_id = part.index_id 
                       AND idx.object_id = part.object_id 
WHERE  idx.type_desc = 'CLUSTERED COLUMNSTORE'; 

Upgrade from an Azure geographical region using restore through the Azure portal

Create a user-defined restore point using the Azure portal

  1. Sign in to the Azure portal.

  2. Navigate to the SQL data warehouse that you want to create a restore point for.

  3. At the top of the Overview section, select +New Restore Point.

    New Restore Point

  4. Specify a name for your restore point.

    Name of Restore Point

Restore an active or paused database using the Azure portal

  1. Sign in to the Azure portal.
  2. Navigate to the SQL data warehouse that you want to restore from.
  3. At the top of the Overview section, select Restore.

     Restore Overview

  4. Select either Automatic Restore Points or User-Defined Restore Points.

    Automatic Restore Points

  5. For User-Defined Restore Points, select a Restore point or Create a new user-defined restore point. Choose a server in a Gen2 supported geographic region.

    User-defined Restore Points

Restore from an Azure geographical region using PowerShell

To recover a database, use the Restore-AzureRmSqlDatabase cmdlet.

Note

You can perform a geo-restore to Gen2! To do so, specify an Gen2 ServiceObjectiveName (e.g. DW1000c) as an optional parameter.

  1. Open Windows PowerShell.
  2. Connect to your Azure account and list all the subscriptions associated with your account.
  3. Select the subscription that contains the database to be restored.
  4. Get the database you want to recover.
  5. Create the recovery request for the database, specifying a Gen2 ServiceObjectiveName.
  6. Verify the status of the geo-restored database.
Connect-AzureRmAccount
Get-AzureRmSubscription
Select-AzureRmSubscription -SubscriptionName "<Subscription_name>"

# Get the database you want to recover
$GeoBackup = Get-AzureRmSqlDatabaseGeoBackup -ResourceGroupName "<YourResourceGroupName>" -ServerName "<YourServerName>" -DatabaseName "<YourDatabaseName>"

# Recover database
$GeoRestoredDatabase = Restore-AzureRmSqlDatabase –FromGeoBackup -ResourceGroupName "<YourResourceGroupName>" -ServerName "<YourTargetServer>" -TargetDatabaseName "<NewDatabaseName>" –ResourceId $GeoBackup.ResourceID -ServiceObjectiveName "<YourTargetServiceLevel>" -RequestedServiceObjectiveName "DW300c"

# Verify that the geo-restored database is online
$GeoRestoredDatabase.status

Note

To configure your database after the restore has completed, see Configure your database after recovery.

The recovered database will be TDE-enabled if the source database is TDE-enabled.

If you experience any issues with your data warehouse, create a support request and reference “Gen2 upgrade” as the possible cause.

Next steps

Your upgraded data warehouse is online. To take advantage of the enhanced architecture, see Resource classes for Workload Management.