Limitations in Azure Database for PostgreSQL - Single Server

The following sections describe capacity and functional limits in the database service.

Maximum connections

The maximum number of connections per pricing tier and vCores are as follows:

Pricing Tier vCore(s) Max Connections
Basic 1 50
Basic 2 100
General Purpose 2 150
General Purpose 4 250
General Purpose 8 480
General Purpose 16 950
General Purpose 32 1500
General Purpose 64 1900
Memory Optimized 2 300
Memory Optimized 4 500
Memory Optimized 8 960
Memory Optimized 16 1900
Memory Optimized 32 1900

When connections exceed the limit, you may receive the following error:

FATAL: sorry, too many clients already

The Azure system requires five connections to monitor the Azure Database for PostgreSQL server.

Functional limitations

Scale operations

  • Dynamic scaling to and from the Basic pricing tiers is currently not supported.
  • Decreasing server storage size is currently not supported.

Server version upgrades

  • Automated migration between major database engine versions is currently not supported. If you would like to upgrade to the next major version, take a dump and restore it to a server that was created with the new engine version.

VNet service endpoints

  • Support for VNet service endpoints is only for General Purpose and Memory Optimized servers.

Restoring a server

  • When using the PITR feature, the new server is created with the same pricing tier configurations as the server it is based on.
  • The new server created during a restore does not have the firewall rules that existed on the original server. Firewall rules need to be set up separately for this new server.
  • Restoring a deleted server is not supported.

UTF-8 characters on Windows

  • In some scenarios, UTF-8 characters are not supported fully in open source PostgreSQL on Windows, which affects Azure Database for PostgreSQL. Please see the thread on Bug #15476 in the postgresql-archive for more information.

Next steps