FAQ

DTU

• What will happen to DTU-based models?

  DTU- and vCore-based models will continue to coexist. At the request of our customers, we released a vCore-based model. These customers want to obtain greater database resource transparency and be able to scale computing and storage separately.

• How does DTU-based SQL Database storage show up in my bill?

  It is billed based on provisioned storage rather than actual usage. For example, the highest provisioned storage selected by the customer is 750GB while actual usage is 418GB. In this case, as P4 includes storage of 500GB, the storage usage will be charged for 750GB-500GB=250GB.

• Pricing example for a DTU-based model used to provision a single database with extra storage

  Suppose an S3 database is preset with 1 TB. Since it has 250 GB of storage capacity, its extra storage capacity is 1024 GB - 250 GB = 774 GB. The unit price for extra storage in the Standard tier is ¥ 1.0812/GB/month, so the price of extra storage is 774 GB x ¥ 1.0812/GB/month = ¥ 804.4128/month. Therefore, the total price of the S3 database is ¥ 969.37/month (eDTU) + ¥ 804.4128/month of extra storage = ¥ 1,773.7828/month.

• Pricing example for a DTU-based model used to provision an elastic pool with extra storage

  Suppose a 125 eDTU Premium pool is preset with 1 TB and has a storage capacity of 250 GB, so its extra storage capacity is 1024 GB - 250 GB = 774 GB. The unit price for extra storage in the Premium pool is about ¥ 2.1624/GB/month, so the price of extra storage is 774 GB x ¥ 2.1624/GB/month = ¥ 1,608.8256/month. Therefore, the total price for the pool is ¥ 2,208.75/month (eDTU) + ¥ 1,608.8256/month of extra storage = ¥ 3,817.5756/month.

• Would automated backups be charged for DTU-based database?

  Automated backups are free of charge, for relevant information please see link: https://docs.azure.cn/en-us/sql-database/sql-database-automated-backups

• Would Long Term Retention Storage under the DTU-based model be provided for free?

  Long Term Retention Storage is chargeable.

VCore

• What is a vCore?

  A virtual core (vCore) represents the logical CPUs available to the server. Customers can choose between two generations of hardware. For servers created using the Gen4 vCore, the vCore is based on the Intel E5-2673 v3 (Haswell) 2.4 GHz processor.

• What are the advantages of a vCore-based model?

  With a vCore-based purchasing model, local workload requirements can be translated to the cloud in a flexible, controlled, and direct manner. This allows independent scaling of calculation and storage resources based on workload requirements.

  A vCore-based model is suitable for SQL Database Managed Instances, single databases, and elastic pool deployment options. These options all use Azure Hybrid Benefit for SQL Server. Therefore, pricing within a vCore-based model applies whether or not you use Hybrid Benefit:

  • Licenses included: Does not include Azure Hybrid Benefit for SQL Server. This option is suitable for customers who are reluctant to apply existing SQL Server licenses with Software Assurance to vCore-based database deployment options.
  • Baseline rate: Discount price that includes Azure Hybrid Benefit for SQL Server. Customers can choose this price by using an SQL Server license with Software Assurance.
• What are virtualization benefits?

  Virtualization benefits apply to virtualized workloads on vCore-based Azure SQL Databases. Use them to convert 1 SQL Enterprise Edition license core through valid Software Assurance to get up to 4 managed instance General Purpose vCores at the baseline rate. This is a cost-effective way to migrate virtualized applications to vCore-based SQL Databases. For example, if you have 4 core licenses for SQL Enterprise Edition, you can get up to 16 General Purpose vCores at the baseline rate.

• Will I be charged for my SQL Database licenses?

  Yes, the pricing announced on the official page of SQL Database is already inclusive of license fees.

• Can I use an SQL Server license on-premises and in the cloud?

  The license must be used on-premises or in the cloud, but there is a grace period of 180 days during which the license can be used both on-premises and in the cloud to facilitate migration.

• What is Azure Hybrid Benefit for SQL Server? Am I eligible to use it?

  Azure Hybrid Benefit for SQL Server can help you to maximize the value of your current license investment and accelerate migration to the cloud. Azure Hybrid Benefit for SQL Server is an Azure-based hybrid benefit. An SQL Server license with Software Assurance can be used through it in order to pay less SQL Database charges (baseline rate). All vCore-based options can be used via Azure Hybrid Benefit for SQL Server: SQL Database Managed Instances, single databases, and elastic pools. You can apply this benefit even if SKUs are active, but please note that the baseline rate will be applied from when you make a selection in the portal. The credit limit will not be reissued.

  You can activate Azure Hybrid Benefit by proving that you have a valid license with Software Assurance in the Azure portal. The working principles for Azure Hybrid Benefit are as follows:

  • If you have the Standard Edition with Software Assurance, issued per core license, choose the General Purpose option and get 1 vCore for every 1 local license core.
  • If you have the Enterprise Edition with Software Assurance, issued per core license, select the Business-Critical option (coming soon) and get 1 vCore for every 1 local license core. Note: The Business-Critical option for Azure Hybrid Benefit for SQL Server is only offered to Enterprise Edition customers.
  • If you have the highly-virtualized Enterprise Edition with Software Assurance, issued per core license, choose the General Purpose option and get 4 vCores for every 1 local license core. This is a unique virtualization benefit that is limited to Azure.
• Can Azure Hybrid Benefit for SQL Server be applied retrospectively?

  No. Azure Hybrid Benefit cannot be applied retrospectively.

• If Software Assurance expires, what will happen to Azure Hybrid Benefit for SQL Server?

  Valid Software Assurance is required to use Azure Hybrid Benefit for SQL Server. If your Software Assurance expires and you do not renew it, you will be redirected to the "license included" pricing corresponding to the SKU.

• How does usage show up on my bill?

  In a vCore-based model, the service is billed at a predictable, hourly rate based on the provisioned compute in vCores, provisioned storage (in GB/month), and backup storage used. There will be additional charges if backup exceeds the total database size (that is, 100% of the database size). vCore hours, configured database storage, consumed IO, and backup storage are itemized on the bill, making it easier for you to see the details of resources you have used. Backup storage of up to 100% of the maximum database size is included, beyond which you are billed for GB/month.

  For example:

  • If an SQL Database exists for 12 hours in a month, the bill will show the cost for 12 hours of vCore usage. If the SQL Database provisioned an additional 100 GB of storage, the bill will show storage usage in units of GB/month prorated hourly and the number of IOs consumed in a month.

  If the uptime of an SQL Database is less than 1 hour, the costs for each hour the database exists are calculated using the highest service tier, provisioned storage, and IO that were used during that hour, regardless of usage or whether the database uptime was less than an hour.

  For example:

  • If you create a Managed Instance and delete it five minutes later, you’ll be charged for 1 database hour.
  • If you create a Managed Instance in the General Purpose tier with 8 vCores, then immediately upgrade it to 16 vCores, you’ll be charged at the 16 vCore rate for the first hour.

  Please Note: For a limited period before June 30, 2018, backup and IO are free of charge.

• How is the serverless compute tier different from the provisioned compute tier of SQL Database?

  The key difference between the serverless and provisioned compute tiers is in the provisioning and billing of compute resources. In the serverless compute tier, compute resources scale dynamically up or down based on the workload’s requirements and are billed on a per-second basis, pausing during periods of inactivity. In the provisioned compute tier, a customer purchases a certain amount of compute resources and is billed for them on an hourly basis.

  The serverless compute tier is generally better suited for single databases with variable usage patterns interspersed with periods of inactivity, or databases with compute resource usage that is difficult to predict. These can benefit from savings due to per-second billing based on the amount of compute resources used.

  The provisioned compute tier is generally better suited for:

  • Single databases with more uniform and more substantial compute utilization over time. Databases with this usage pattern are generally less expensive in the provisioned compute tier.
  • Multiple databases with varying and unpredictable compute usage that can be consolidated within an elastic pool for better price optimization.
• Which purchase model and service tier are supported in serverless?

  Serverless is offered on the vCore-based purchase model and the single database service tier.

• How does billing work in serverless?

  The total bill is the summation of the compute bill and storage bill.

  Billing for compute is on a per-second rate based on actual usage of compute resources (for details, please see the next question: “ How is the compute bill calculated in the serverless compute tier? ”).

  Billing for storage within a given service tier is the same for both the serverless and provisioned compute tiers.

• How is the compute bill calculated in serverless?

  Compute is billed on a per-second rate based on actual usage subject to billing for minimum compute resources provisioned while the database is online.

  The amount of compute billed each second is based on the maximum of CPU and memory used each second. To compare CPU with memory for billing purposes, memory is normalized into units of vCores by rescaling the amount of memory in GB by 3 GB per vCore. If the amount of CPU and memory used is less than the minimum amount provisioned, then the provisioned amount is billed. When the database is paused, customers pay nothing for compute and only storage is billed.

  Customers can configure the range of compute capacity available (min vCores and max vCores) for the database and the period of inactivity before a database is paused (auto-pause delay).

  For example, let’s say you configure min vCores as 1 , max vCores as 4 and auto-pause delay as 6 hours. This configuration corresponds to a minimum memory of around 6 GB and a maximum memory of 12 GB . The below table represents your bill if usage varies as follows during a 12-hour period:

  Duration	CPU used (vCores)	Memory used (GB)	Billed vCores	Billed vCore-seconds
  1 minute (60 seconds)	1.5	3	1.5 (based on CPU used) 1	90
  1 minute (60 seconds)	4	9	4 (based on CPU used)	240
  1 minute (60 seconds)	0.5	12	4 (based on memory used)	240
  6 hours (21,600 seconds)	0	2	1 (based on minimum compute resources) 2	21,600
  5 hours 56 minutes (21,360 seconds)	0	0	0 (database is paused after 6-hour auto-pause delay)	0
  1 minute (60 seconds)	0.5	9	3 (based on memory used)	180
  Total: 12 hours				Total: 22,350

  ¹ CPU used (1.5 vCores) is greater than memory used after rescaling based on 3 GB per vCore (3 GB ÷ 3 vCores per GB = 1 vCore). Hence, 1.5 vCores are billed.

  ² CPU used (0 vCores) and memory used after rescaling based on 3 GB per vCore (2 GB ÷ 3 vCores per GB = 0.67 vCores) are both lower than the minimum compute resources (1 vCore). Hence, 1 vCore is billed.

  Total bill for compute during this 12-hour period will be ￥12.155.

Overview

• How is Managed Instance priced?

  Managed Instance allows for scaling compute and storage independently. Customers pay for compute measured in vCores, storage and backup measured in gigabytes (GB), and number of IOs consumed.

  Managed Instance has two price options:

  • License included: Excludes Azure Hybrid Benefit for SQL Server . This option is for customers who choose not to apply their existing SQL Server licenses with Software Assurance to Managed Instance.
  • Base rate: Reduced price that includes Azure Hybrid Benefit for SQL Server. Customers can opt into this price by using their SQL Server licenses with Software Assurance.
• How can I stop being billed for database?

  Billing for database will stop upon deletion.

• Do I need to bear any network data transfer costs?

  There will be no additional charges for the entry or exit of network data during the public preview. Additional fees will be charged after the official release.

• Do I have to move to a vCore-based model?

  You don’t need to move to a vCore-based model. The introduction of vCore-based deployment options for elastic pools and single databases embodies our commitment to customer choice and flexibility. If you wish to continue using a DTU-based model, no action is required and your experience and billing methods will remain the same. In addition to vCore-based models, a DTU-based model is still a viable option for purchasing SQL Database.

• How should I choose between a DTU- or vCore-based model?

  Data transfer units (DTU) are based on a mixture of CPU, memory, read, and write measurements. DTU-based performance levels represent provisioned resource bundles that drive different levels of application performance. If you do not want to worry about underlying resources, and want to use a simple provisioned bundle and pay a fixed monthly fee, a DTU-based model may better meet your needs.

• Do I need to take my application offline to convert from a DTU-based database to a vCore-based service tier?

  The new service tiers offer a simple online dialog method that is similar to the existing process for upgrading databases from the Standard to the Premium service tier and vice versa. The portal can be launched using Portal, ARM, PowerShell, Azure CLI or T-SQL.