Upgrade your data warehouse to Gen2

Microsoft is helping drive down the entry-level cost of running a data warehouse. Lower compute tiers capable of handling demanding queries are now available for Azure SQL Data Warehouse. Read the full announcement Lower compute tier support for Gen2. The new offering is available in the regions noted in the table below. For supported regions, existing Gen1 data warehouses can be upgraded to Gen2 through either:

  • The automatic upgrade process: Automatic upgrades don't start as soon as the service is available in a region. When automatic upgrades start in a specific region, individual DW upgrades will take place during your selected maintenance schedule.
  • Self-upgrade to Gen2: You can control when to upgrade by doing a self-upgrade to Gen2. If your region is not yet supported, you can restore from a restore point directly to a Gen2 instance in a supported region.

Automated Schedule and Region Availability Table

The following table summarizes by region when the Lower Gen2 compute tier will be available and when automatic upgrades start. The dates are subject to change. Check back to see when your region becomes available.

* indicates a specific schedule for the region is currently unavailable.

Region Lower Gen2 available Automatic upgrades begin
Australia East Available June 1, 2019
Australia Southeast Available May 1, 2019
Brazil South Available June 1, 2019
Canada Central Available June 1, 2019
Canada East * *
Central US Available June 1, 2019
China East * *
China East 2 * Gen2 only
China North * *
China North 2 Available Gen2 only
East Asia Available June 1, 2019
East US Available June 1, 2019
East US 2 Available June 1, 2019
France Central * June 1, 2019
Germany Central * *
Germany West Central September 1, 2019 January 2, 2020
India Central Available June 1, 2019
India South Available June 1, 2019
Japan East Available June 1, 2019
Japan West Available May 1, 2019
Korea Central Available June 1, 2019
Korea South Available May 1, 2019
North Central US Available May 1, 2019
North Europe Available June 1, 2019
South Central US Available June 1, 2019
South East Asia Available June 1, 2019
UK South Available, 2019 June 1, 2019
UK West * *
West Central US September 2, 2019 January 2, 2020
West Europe Available June 1, 2019
West US Available June 1, 2019
West US 2 Available June 1, 2019

Automatic upgrade process

Based on the availability chart above, we'll be scheduling automated upgrades for your Gen1 instances. To avoid any unexpected interruptions on the availability of the data warehouse, the automated upgrades will be scheduled during your maintenance schedule. The ability to create a new Gen1 instance will be disabled in regions undergoing auto upgrade to Gen2. For more information on schedules, see View a maintenance schedule

The upgrade process will involve a brief drop in connectivity (approximately 5 min) as we restart your data warehouse. Once your data warehouse has been restarted, it will be fully available for use. However, you may experience a degradation in performance while the upgrade process continues to upgrade the data files in the background. The total time for the performance degradation will vary dependent on the size of your data files.

You can also expedite the data file upgrade process by running Alter Index rebuild on all primary columnstore tables using a larger SLO and resource class after the restart.

Note

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

Self-upgrade to Gen2

You can choose to self-upgrade by following these steps on an existing Gen1 data warehouse. If you choose to self-upgrade, you must complete it before the automatic upgrade process begins in your region. Doing so ensures that you avoid any risk of the automatic upgrades causing a conflict.

There are two options when conducting a self-upgrade. You can either upgrade your current data warehouse in-place or you can restore a Gen1 data warehouse into a Gen2 instance.

  • Upgrade in-place - This option will upgrade your existing Gen1 data warehouse to Gen2. The upgrade process will involve a brief drop in connectivity (approximately 5 min) as we restart your data warehouse. Once your data warehouse has been restarted, it will be fully available for use. If you experience issues during the upgrade, open a support request and reference “Gen2 upgrade” as the possible cause.

  • Upgrade from restore point - Create a user-defined restore point on your current Gen1 data warehouse and then restore directly to a Gen2 instance. The existing Gen1 data warehouse will stay in place. Once the restore has been completed, your Gen2 data warehouse will be fully available for use. Once you have run all testing and validation processes on the restored Gen2 instance, the original Gen1 instance can be deleted.

    • Step 1: From the Azure portal, create a user-defined restore point.
    • Step 2: When restoring from a user-defined restore point, set the "performance Level" to your preferred Gen2 tier.

You may experience a period of degradation in performance while the upgrade process continues to upgrade the data files in the background. The total time for the performance degradation will vary dependent on the size of your data files.

To expedite the background data migration process, you can immediately force data movement by running Alter Index rebuild on all primary columnstore tables you'd be querying at a larger SLO and resource class.

Note

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

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

For more information, see Upgrade to Gen2.

Migration frequently asked questions

Q: Does Gen2 cost the same as Gen1?

  • A: Yes.

Q: How will the upgrades affect my automation scripts?

  • A: Any automation script that references a Service Level Objective should be changed to correspond to the Gen2 equivalent. See details here.

Q: How long does a self-upgrade normally take?

  • A: You can upgrade in place or upgrade from a restore point.
    • Upgrading in place will cause your data warehouse to momentarily pause and resume. A background process will continue while the data warehouse is online.
    • It takes longer if you are upgrading through a restore point, because the upgrade will go through the full restore process.

Q: How long will the auto upgrade take?

  • A: The actual downtime for the upgrade is only the time it takes to pause and resume the service, which is between 5 to 10 minutes. After the brief down-time, a background process will run a storage migration. The length of time for the background process is dependent on the size of your data warehouse.

Q: When will this automatic upgrade take place?

  • A: During your maintenance schedule. Leveraging your chosen maintenance schedule will minimize disruption to your business.

Q: What should I do if my background upgrade process seems to be stuck?

  • A: Kick off a reindex of your Columnstore tables. Note that reindexing of the table will be offline during this operation.

Q: What if Gen2 does not have the Service Level Objective I have on Gen1?

  • A: If you are running a DW600 or DW1200 on Gen1, it is advised to use DW500c or DW1000c respectively since Gen2 provides more memory, resources, and higher performance than Gen1.

Q: Can I disable geo-backup?

  • A: No. Geo-backup is an enterprise feature to preserve your data warehouse availability in the event a region becomes unavailable. Open a support request if you have further concerns.

Q: Is there a difference in T-SQL syntax between Gen1 and Gen2?

  • A: There is no change in the T-SQL language syntax from Gen1 to Gen2.

Q: Does Gen2 support Maintenance Windows?

  • A: Yes.

Q: Will I be able to create a new Gen1 instance after my region has been upgraded?

  • A: No. After a region has been upgraded, the creation of new Gen1 instances will be disabled.

Next steps