What is Azure SQL?

In this Azure SQL tutorial, you will know what is Azure SQL. We have discussed the features of Azure SQL, things you should consider before buying a plan, and a number of frequently asked questions.

  • Introduction to Azure SQL Server
  • Azure SQL Features
  • Azure SQL server pricing
  • Is Azure SQL the same as SQL Server?
  • Difference between Azure SQL and SQL Server
  • What is the use of SQL Server in Azure?
  • Is SQL Server free in Azure?
  • Is Azure SQL Database free for students?
  • Is Azure SQL Database PaaS or SaaS?
  • Is Azure SQL faster than on premise?

Introduction to Azure SQL

What is Azure SQL? The Azure SQL is a cloud-based SQL Server environment that where you work on remote machines provided by the Microsoft Azure cloud services. You do not need to install SQL Server on your own machine. Instead, you work on other machines and pay for them according to your requirements. In case your requirements increase, you can easily scale your database.

Because of working in a cloud environment, you get enough security for your database because all of the security is managed by the cloud service provider i.e. Microsoft Azure. There are a lot of features you get using Azure SQL. We will discuss these features in detail.

Azure SQL
Azure SQL

Azure SQL Features

When you are working on a Cloud, you get a long list of very useful features. the same is the case with Azure SQL. The Azure SQL provides all the features that you get when working on a cloud. Let us discuss these features one by one.

1. Flexibility

The Azure SQL database is very flexible to use. If you want to start a small-scale business or your requirements are very low, you do not need to purchase robust hardware and use SQL Server. This will cost you a lot. Instead, you can use Azure SQL and pay for only what you use. The pricing is based on the time you are using.

If your business is growing or the requirements are increasing, you can easily scale the database within seconds. It also provides the auto-scale feature that automatically increases the size of resources based on the increasing requirements.

For example, if your requirement is for only 250GB per month, you can go through the plans and take the subscription accordingly. Suppose, the data in the database is increasing at a very fast rate and you know that soon you will need 1TB of data, you can change your plan anytime.

And if you are using the auto-scale feature, you do not need to worry about it. The Azure service will automatically increase the size of your resources.

2. Fully Managed Services

The Azure SQL database is fully managed by Microsoft Azure. Most of the services like tuning the database, performing regular database tasks like backups, performance monitoring, and tuning are managed by Azure.

You just need to assign the task and do not need to worry about the scenes behind. Azure SQL provides you the latest and updated database. You do not need to do it yourself.

3. Security

The Azure SQL is a very secure platform as it is deployed on the cloud service. It is very difficult to breach the Azure SQL database security. Using artificial intelligence, a firewall detects and prevents any kind of malicious activities or unwanted requests made to the database engine. You can also configure the firewall according to your requirements to make the database more secure.

4. High Availability

The Azure SQL database provides availability at any instance of time. For example, if the load on the server is increased, the database will be automatically scaled and the users will not face the problem of an unresponsive server.

Also, Azure SQL provides a backup and restore facility so that in case of hardware failure, the database is still available. Azure SQL also provides a feature called active geo-replication which creates a replica of the original server in other remotely located data centers, increasing the availability of the database.

Also, read, How to Create a Single Database in Azure SQL

Azure SQL pricing

When you use Azure SQL, you pay only for what you use. You just have to buy a subscription plan according to your requirements. There are a number of plans offered by Azure SQL that you can consider. But, you need to have basic knowledge of some concepts before buying a plan to choose the best plan according to your requirements. Let us discuss these concepts.

Deployment Models:

The first thing that you have to decide while buying a plan is to select the deployment model that will suit your requirements. There are two deployment models for Azure SQL:

  1. Single Databse: Single database is a fully isolated database that has its own resources. This means it does not share its resources with others. You can use this database if you know the exact requirements and you can fully utilize it.
  2. Elastic Pool: In elastic pool resource type, you can share the resources in a scenario where you you have multiple database and you do not know the exact requirements of the resources. This is a very cost-effective solution in such scenarios. For example, suppose you have two databases. One database is very busy and is lacking resources and on the other hand, there is a database sitting idle or using a very less resources. If you are using elastic pools then you will not face such situation as both the databases will share their resources.

Purchasing Models:

Azure SQL has introduced some purchasing models based on different requirements of users. A purchasing model defines which type of resources a user wants to use. The Azure SQL offers two purchasing models. We will discuss each model one by one.

VCore Based:

VCore stands for the virtual core. As the name suggests, a vCore is a logical CPU core that Azure offers you as a resource. In this model, you are offered a combination of CPU power, memory, and storage. In the vCore model purchase, the main focus is on the underlying infrastructure.

You can use this model if you know to fully utilize the hardware resources. It requires some technical expertise to fully utilize the resources. But once you are ready, it will give you a very cost-effective solution and gives you flexibility, transparency, and more control over your resources.

Service Tiers in vCore based model:

A service tier defines what kind of services you will be offered like the type of hardware, backup limit, etc. Azure SQL offers three service tiers when you purchase a vCore based plan:

  • General Purpose
  • Business Critical
  • Hyperscale

You can know more about these service tiers, what they offer in every service tier, on the official documentation of Azure SQL.

Compute Tiers in vCore based model:

A single database also offers two compute tiers if you are using a vCore based purchasing model. These two are:


In the serverless compute tier, you can even pause the database and you do not need to pay till the database is paused.

A time delay can be set for the inactivity period such that after that inactivity period, the database will be paused. The database is resumed automatically once there is some activity or log-in.

This is a very good approach if you do not know the exact requirements of your database and you know you will face a lot of inactivity in the database. But, the computing cost is higher than the provisioned model.

Also, the performance becomes slow after some inactivity. Therefore, use this tier only if your database faces inactivity or has irregular patterns of inactivity and you can compromise with a little lower performance.


This compute tier is cheaper if your requirements are high. You are billed per hour and you should use it if your database is very active. Also, using this model will give you better performance.

Use this compute tier if the database activity is regular, you know the database requirements well and you cannot afford any performance issue or delay.

DTU Based:

In DTU based model, you are offered resources in the form of DTUs. DTU stands for Database Transaction Units. A DTU is a bundle of computing power, storage, memory, and I/O operations.

This model is based on the overall performance requirements of a database including the number of read/write operations. It is very simple to use as most of the things are preconfigured.

You just need to calculate the workload requirements of your database and purchase the required number of DTUs.

Service Tiers in DTU based model:

The DTU based purchasing model offers three different service tiers based on the type of user requirements:

  • Basic
  • Standard
  • Premium

You can learn more about the service tiers in DTU based model on the official documentation of Azure SQL.

Thus, these were some important factors and considerations that you should know before purchasing a subscription plan for the Azure SQL database.

After knowing these things, you can buy a subscription plan that suits you best and is cost-effective. You can also make an estimate of your cost using the Azure SQL database price calculator.

Is Azure SQL the same as SQL Server?

The Azure SQL is a kind of subset of SQL Server. It supports most of the functions provided by the SQL Server. Azure SQL works in a cloud environment. On the other hand, SQL Server can be used on virtual machines on the cloud as well as on-premise.

The basic functionality of Azure SQL and SQL Server is the same. However, there are some differences between the two.

Difference between Azure SQL and SQL Server

The following are the points of difference between Azure SQL and SQL Server:

AreaAzure SQLSQL Server
1. FeaturesLess basic features are available but few extra features are provided by the cloud. For example, inbuilt security features, automatic backup, etc.More features but you have to manage the features manually.
2. SecurityThe Azure SQL provides some inbuilt security features like a robust firewall which you can configure to make the database secure.In SQL Server, you have to take care of the database security manually. The level of security depends on the user.
3. BackupAutomatic backup facility is provided.You need some scripts to make the backup process automatic.
4. UpdatesYou always use the latest version of the database engine. The Azure SQL updates it automatically to the latest version.You have to manually update the database engine.
5. LicensingYou do not need to purchase any license. You just have to buy a subscription for using the cloud services.You have to purchase the license for SQL Server Enterprise edition if you want to use it commercially.
6. UsageGood to use if you do not want to manage the administrative tasks manually. Best for small-scale businesses and startups where you do not want to maintain the hardware and perform database administrative operations.Good for large scale business where one can maintain his own data center and perform all the database administrative operations by himself.
7. Monitoring and ReportingIt is integrated with monitoring tools making it easy to monitor the database.You need to use some monitoring tools and some custom scripts by yourself for monitoring and reporting.
8. SQL AgentNo SQL Agent.SQL Agent is provided.
9. db_mailNo available.Available
10. Linked ServerNot AvailableAvailable
11. Underlying InfrastructureThe computing resources are vCores or DTUs and you have no direct control over these resources.You have full control over the underlying resources. You can use them in any way you want.
Difference Between Azure SQL and SQL Server

What is the use of SQL Server in Azure?

SQL Server is a relational database adopted by Microsoft. We can use the SQL Server in a cloud environment like Azure, Amazon Web Services, etc instead of deploying on-premise. You can use SQL Server and also enjoy the benefits of the cloud environment.

You can create a virtual machine and deploy SQL Server on the virtual machine on any cloud you want. However, Microsoft provides Azure SQL platform as a service which you can use as an alternative to SQL Server.

Azure SQL behaves the same as SQL Server but has some features different from SQL Server.

Thus, it totally depends on your requirements, what type of instance you want to create and use SQL Server on Azure.

Is SQL Server free in Azure?

If you create a new account, you can get 12 months free subscription to Azure SQL and some other services. Microsoft Azure provides few free services for 12 months and also some free credits that you can use to create paid instances.

The 12-month free subscription of Azure SQL includes a 250GB S0 instance with 10 database transaction units. Also, you can use the free credits to expand the SQL database.

Is Azure SQL Database free for students?

Microsoft Azure offers some free services and USD 100 credits to the students. For this, you must be a student and you must verify your identity. You will be USD 100 credits for 12 months. You can use your USD 100 credits for various services. The services include computing power, storage, memory, etc. If you have used your USD 100 credits before 12 months, you have to pay more if you want to use more services.

After 12 months, if you are still a student, you can renew your subscription and get USD 100 credits and free services again. If you are not a student after 12 months, your subscription will be disabled and you have to upgrade your account.

Is Azure SQL Database PaaS or SaaS?

The Azure SQL database is a PaaS i.e. platform as a service database engine. It is a platform where you can develop your database applications. The Azure SQL provides several platform-based services that you need frequently.

Some of these services are backups and restore, scheduling tasks, updating the database to the latest versions, performance tuning, and optimization of the database.

Also Read: Pause and resume Azure SQL database

Is Azure SQL faster than on premise?

The speed and performance of these two depend on various factors. In some cases, you will find that the on-premise SQL Server is faster than the Azure SQL. This is because there is a lot of overhead in the Azure SQL database operations,

The Azure SQL database provides several automatic features, thus increasing the overhead. On the other hand, you can define your own ways of managing the on-premise SQL Server. You can define what operations to perform to manage the database.

However, you will also find that the Azure SQL is faster than the on-premise SQL Server database in some cases. Because the Azure SQL is always up to date with the new features that optimize the database and boost performance.

Thus, it totally depends on the management operations that you want to perform over a database that decides the performance.

  • Introduction to Azure SQL
  • Azure SQL Features
  • Azure SQL server pricing
  • Is Azure SQL the same as SQL Server?
  • Difference between Azure SQL and SQL Server
  • What is the use of SQL Server in Azure?
  • Is SQL Server free in Azure?
  • Is Azure SQL Database free for students?
  • Is Azure SQL Database PaaS or SaaS?
  • Is Azure SQL faster than on premise?