Azure SQL Database

Azure SQL Database provides the following deployment options for an Azure SQL database:

• As a single database with its own set of resources managed via a logical server.
• As a pooled database in an elastic pool with a shared set of resources managed through a logical server

In general, elastic pools are designed for a typical software-as-a-service (SaaS) application pattern, where there is one database per customer or tenant. Purchasing individual databases and over provisioning to meet the variable and peak demand for each database is often not cost efficient, but with pools, you manage the collective performance and the databases scale up and down automatically. Our intelligent engine recommends a pool for databases when a usage pattern warrants it. For details, see elastic pool guidance.

The Azure Hybrid Benefit for SQL Server helps you maximize the value from your current licensing investments and accelerate your migration to the cloud. Azure Hybrid Benefit for SQL Server is an Azure-based benefit that enables you to use your SQL Server licenses with active Software Assurance to pay a reduced rate (“base rate”) on vCore-based Azure SQL Database and Azure SQL Managed Instance. You may apply this benefit even if the SKU is active but note the base rate will be applied from the time you select it in the portal. No credit will be issued retroactively.

You can activate the Azure Hybrid Benefit via the Azure Portal by attesting you have sufficient active licenses with Software Assurance.

The Azure Hybrid Benefit for SQL Server provides:

• The ability to move your licenses to a fully managed platform-as-a-service (PaaS) product. Azure is the only cloud that provides this ability. Amazon Web Services Relational Database Service (RDS) is not eligible for bring-your-own-license (BYOL) and must be offered as "license-included."
• Four cores in the cloud for every one core on-premises for Enterprise edition customers in the general purpose or Hyperscale service tiers.
• 180 days of dual-use rights to apply to current deployment (on premises or on third-party cloud) and in Azure to allow for data migration.

No. Azure SQL Database is a fully managed database service, which means that Microsoft operates SQL Server for you and ensures its availability and performance. SQL Database also includes innovative features to enhance your business continuity, such as built-in high availability. A comprehensive security portfolio allows you to implement intelligent features like threat detection, so that don’t have to worry about administering or maintaining hundreds or thousands of your SQL Server databases. View the full feature comparison of Azure SQL Database and SQL Server.

The vCore-based service tiers are primarily differentiated by availability, storage type, and IOPS:

General Purpose offers a budget-oriented and balanced set of compute and storage options where I/O performance or failover time is not the priority.

Hyperscale is appropriate for most business workloads, optimized for online transaction processing (OLTP) and hybrid transactional analytical workloads (HTAP), with highly scalable storage size, read scale-out, and fast database restore capabilities.

Business Critical is best for OLTP applications with high transaction rate and low IO latency. It offers highest resilience to failures and fast failovers by using multiple synchronously updated replicas.

Connectivity between your Microsoft Azure SQL Database and the Azure Internet gateway is guaranteed at least 99.99 percent of the time, regardless of your service tier. 0.01 percent is reserved for patches, upgrades, and failovers. For more information, read the SLA. For information about the availability architecture of Azure SQL Database, see high availability and Azure SQL Database.