Aurora PostgreSQL Limitless Database requirements and considerations

The following AWS Regions are available:

The AWS CLI procedures in this guide assume that you are using one of the available AWS Regions. For information on how to set the default AWS Region for the AWS CLI, see How to set environment variables in the AWS Command Line Interface User Guide for Version 2.

Aurora PostgreSQL Limitless Database supports only the Aurora I/O-Optimized DB cluster storage configuration. For more information, see Storage configurations for Amazon Aurora DB clusters.

Aurora PostgreSQL Limitless Database uses a special Aurora PostgreSQL DB engine version for Aurora PostgreSQL Limitless Database: 16.4-limitless.

Your DB cluster can't have any writer or reader DB instances.

You must use Enhanced Monitoring and Performance Insights. The Performance Insights retention time must be at least 1 month (31 days).

You must export the PostgreSQL log to Amazon CloudWatch Logs.

You can have only one DB shard group per DB cluster.

You can have up to five DB shard groups per AWS Region.

Therefore, you can have up to five Aurora PostgreSQL Limitless Database DB clusters per AWS Region. For more information, see Quotas in Amazon Aurora.

You can set the maximum capacity of a DB shard group to 16–6144 ACUs. For capacity limits higher than 6144 ACUs, contact AWS.

The initial number of routers and shards is determined by the maximum capacity that you set when you create a DB shard group. For more information, see Correlating DB shard group maximum capacity with the number of routers and shards created.

The number of routers and shards doesn't change when you modify the maximum capacity of a DB shard group.

Make sure that the DB subnet where you create the DB shard group has enough free IP addresses for connecting with the DB shard group. You need one IP address for each router and up to three IP addresses for each shard in the DB shard group.

For more information on the number of routers created when you create a DB shard group, see Correlating DB shard group maximum capacity with the number of routers and shards created.

If you make your DB shard group publicly accessible, make sure to set up an internet gateway in your VPC.

You use SQL functions to split shards and add routers.

Merging shards isn't supported.

You can't delete individual shards and routers.

You can't modify (perform UPDATE operations on) shard keys in any way, including changing their values in table rows.

To change a shard key, delete and then re-create it.

The repeatable read, read committed, and read uncommitted isolation levels are supported. You can't set the isolation level to serializable.

Some SQL commands aren't supported. For more information, see Aurora PostgreSQL Limitless Database reference.

Not all PostgreSQL extensions are supported. For more information, see Extensions.

When creating a shard group, or when adding new shard group nodes (shards or routers), those nodes are created in one of the Availability Zones (AZs) available to the DB cluster. You can't choose a specific AZ for individual nodes.

If you use a compute redundancy of 2 (two compute standbys for the DB shard group), make sure that your DB subnet group has at least three AZs.

We recommend that you use AWS managed policies to limit permissions for your database and applications to those that customers need for their use cases. For more information, see Policy best practices.

When you create your Aurora PostgreSQL Limitless Database DB cluster, you only set scaling parameters for the DB shard group.

You can't stop or start a DB cluster that contains a DB shard group.

If you need to delete your DB cluster, you must delete the DB shard group first.

Aurora PostgreSQL Limitless Database can't be a replication source.

Active Directory (Kerberos) authentication

Amazon DevOps Guru

Amazon ElastiCache

Amazon RDS Blue/Green Deployments

Amazon RDS Proxy

Aurora Auto Scaling (adding reader instances to the DB cluster automatically)

Aurora Global Database

Aurora machine learning

Aurora recommendations

Aurora Serverless v1

Aurora zero-ETL integrations

AWS Lambda integration

AWS Secrets Manager

Babelfish for Aurora PostgreSQL

Cloning DB clusters

Custom endpoints

Database activity streams

Read replicas