AWS Documentation » Amazon Relational Database Service (RDS) » User Guide for Aurora » Limits for Amazon RDS

Limits for Amazon RDS

This topic describes the resource limits and naming constraints for Amazon Aurora.

Limits in Amazon RDS

Each AWS account has limits, for each AWS Region, on the number of Amazon RDS resources that can be created. Once a limit for a resource has been reached, additional calls to create that resource fail with an exception.

The following table lists the resources and their limits per region.

Resource	Default Limit
Clusters	40
Cluster parameter groups	50
Cross-region snapshots copy requests	5
DB Instances	40
Event subscriptions	20
Manual snapshots	100
Manual cluster snapshots	100
Option groups	20
Parameter groups	50
Reserved instances	40
Rules per DB security group	20
Rules per VPC security group	50 inbound 50 outbound
DB Security groups	25
VPC Security groups	5
Subnet groups	50
Subnets per subnet group	20
Tags per resource	50

Note

By default, you can have up to a total of 40 Amazon RDS DB instances. If your application requires more DB instances, you can request additional DB instances via this request form Request RDS DB instance limit.

Backups managed by AWS Backup are considered manual snapshots for the manual snapshot limit. For information about AWS Backup, see the AWS Backup Developer Guide.

Naming Constraints in Amazon RDS

The following table describes naming constraints in Amazon RDS.

DB instance identifier	Must contain 1 to 63 alphanumeric characters or hyphens. First character must be a letter. Cannot end with a hyphen or contain two consecutive hyphens. Must be unique for all DB instances per AWS account, per region.
Database name	Database name constraints differ for each database engine. Amazon Aurora MySQL Must contain 1 to 64 alphanumeric characters. Cannot be a word reserved by the database engine. Amazon Aurora PostgreSQL Must contain 1 to 63 alphanumeric characters. Must begin with a letter or an underscore. Subsequent characters can be letters, underscores, or digits (0-9). Cannot be a word reserved by the database engine.
Master user name	Master user name constraints differ for each database engine. Amazon Aurora MySQL Must contain 1 to 16 alphanumeric characters. First character must be a letter. Cannot be a word reserved by the database engine. Amazon Aurora PostgreSQL Must contain 1 to 63 alphanumeric characters. First character must be a letter. Cannot be a word reserved by the database engine.
Master password	The password for the master database user can be any printable ASCII character except "/", """, or "@". Master password constraints differ for each database engine. Amazon Aurora MySQL Must contain 8 to 41 characters. Amazon Aurora PostgreSQL Must contain 8 to 128 characters.
DB parameter group name	Must contain from 1 to 255 alphanumeric characters. First character must be a letter. Hyphens are allowed, but the name cannot end with a hyphen or contain two consecutive hyphens.
DB subnet group name	Must contain from 1 to 255 characters. Alphanumeric characters, spaces, hyphens, underscores, and periods are allowed.

Amazon Aurora File Size Limits

With Aurora, the table size limit is only constrained by the size of the Aurora cluster volume. As a result, the maximum table size for an Aurora MySQL DB cluster is 64 tebibytes (TiB) and for an Aurora PostgreSQL DB cluster it is 32 TiB. We recommend that you follow table design best practices, such as partitioning of large tables.