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Choose the right Azure Database for PostgreSQL - Flexible Server hosting option in Azure

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APPLIES TO: Azure Database for PostgreSQL - Flexible Server

Important

Azure Database for PostgreSQL - Single Server is on the retirement path. We strongly recommend that you upgrade to Azure Database for PostgreSQL - Flexible Server. For more information about migrating to Azure Database for PostgreSQL - Flexible Server, see What's happening to Azure Database for PostgreSQL Single Server?.

With Azure, your PostgreSQL workloads can run in a hosted virtual machine infrastructure as a service (IaaS) or as a hosted platform as a service (PaaS). PaaS has multiple deployment options, each with multiple service tiers. When you choose between IaaS and PaaS, you must decide if you want to manage your database, apply patches, and make backups, or if you want to delegate these operations to Azure.

When making your decision, consider the following option in PaaS or alternatively running on Azure VMs (IaaS)

PostgreSQL on Azure VMs option falls into the industry category of IaaS. With this service, you can run a PostgreSQL server inside a fully managed virtual machine on the Azure cloud platform. All recent versions and editions of PostgreSQL can be installed on an IaaS virtual machine. In the most significant difference from Azure Database for PostgreSQL flexible server, PostgreSQL on Azure VMs offers control over the database engine. However, this control comes at the cost of responsibility to manage the VMs and many database administration (DBA) tasks. These tasks include maintaining and patching database servers, database recovery, and high-availability design.

The main differences between these options are listed in the following table:

Attribute Postgres on Azure VMs Azure Database for PostgreSQL flexible server as PaaS
Availability SLA - Virtual Machine SLA - Azure Database for PostgreSQL flexible server
OS and PostgreSQL patching - Customer managed Automatic with optional customer managed window
High availability - Customers architect, implement, test, and maintain high availability. Capabilities might include clustering, replication etc. Built-in
Zone Redundancy - Azure VMs can be set up to run in different availability zones. For an on-premises solution, customers must create, manage, and maintain their own secondary data center. Yes
Hybrid Scenario - Customer managed Supported
Backup and Restore - Customer Managed Built-in with user configuration on zone-redundant storage
Monitoring Database Operations - Customer Managed All offer customers the ability to set alerts on the database operation and act upon reaching thresholds
Advanced Threat Protection - Customers must build this protection for themselves. Not available during Preview
Disaster Recovery - Customer Managed Supported
Intelligent Performance - Customer Managed Supported

Total cost of ownership (TCO)

TCO is often the primary consideration that determines the best solution for hosting your databases. This is true whether you're a startup with little cash or a team in an established company that operates under tight budget constraints. This section describes billing and licensing basics in Azure as they apply to Azure Database for PostgreSQL flexible server and PostgreSQL on Azure VMs.

Billing

Azure Database for PostgreSQL flexible server is currently available as a service in several tiers with different prices for resources. All resources are billed hourly at a fixed rate. For the latest information on the currently supported service tiers, compute sizes, and storage amounts, see pricing page You can dynamically adjust service tiers and compute sizes to match your application's varied throughput needs. You're billed for outgoing Internet traffic at regular data transfer rates.

With Azure Database for PostgreSQL flexible server, Microsoft automatically configures, patches, and upgrades the database software. These automated actions reduce your administration costs. Also, Azure Database for PostgreSQL flexible server has automated backup-link capabilities. These capabilities help you achieve significant cost savings, especially when you have a large number of databases. In contrast, with PostgreSQL on Azure VMs you can choose and run any PostgreSQL version. However, you need to pay for the provisioned VM, storage cost associated with the data, backup, monitoring data and log storage and the costs for the specific PostgreSQL license type used (if any).

Azure Database for PostgreSQL flexible server provides built-in high availability at the zonal-level (within an AZ) for any kind of node-level interruption while still maintaining the SLA guarantee for the service. Azure Database for PostgreSQL flexible server provides uptime SLAs with and without zone-redundant configuration. However, for database high availability within VMs, you use the high availability options like Streaming Replication that are available on a PostgreSQL database. Using a supported high availability option doesn't provide another SLA. But it does let you achieve greater than 99.99% database availability at more cost and administrative overhead.

For more information on pricing, see the following articles:

Administration

For many businesses, the decision to transition to a cloud service is as much about offloading complexity of administration as it is about cost.

With IaaS, Microsoft:

  • Administers the underlying infrastructure.
  • Provides automated patching for underlying hardware and OS

With PaaS, Microsoft:

  • Administers the underlying infrastructure.
  • Provides automated patching for underlying hardware, OS and database engine.
  • Manages high availability of the database.
  • Automatically performs backups and replicates all data to provide disaster recovery.
  • Encrypts the data at rest and in motion by default.
  • Monitors your server and provides features for query performance insights and performance recommendations.

With Azure Database for PostgreSQL flexible server, you can continue to administer your database. But you no longer need to manage the database engine, the operating system, or the hardware. Examples of items you can continue to administer include:

  • Databases
  • Sign-in
  • Index tuning
  • Query tuning
  • Auditing
  • Security

Additionally, configuring high availability to another data center requires minimal to no configuration or administration.

  • With PostgreSQL on Azure VMs, you have full control over the operating system and the PostgreSQL server instance configuration. With a VM, you decide when to update or upgrade the operating system and database software and what patches to apply. You also decide when to install any other software such as an antivirus application. Some automated features are provided to greatly simplify patching, backup, and high availability. You can control the size of the VM, the number of disks, and their storage configurations. For more information, see Virtual machine and cloud service sizes for Azure.

Time to move to Azure Database for PostgreSQL flexible server (PaaS)

  • Azure Database for PostgreSQL flexible server is the right solution for cloud-designed applications when developer productivity and fast time to market for new solutions are critical. With programmatic functionality that is like DBA, the service is suitable for cloud architects and developers because it lowers the need for managing the underlying operating system and database.

  • When you want to avoid the time and expense of acquiring new on-premises hardware, PostgreSQL on Azure VMs is the right solution for applications that require a granular control and customization of PostgreSQL engine not supported by the service or requiring access of the underlying OS.

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