The Supported PostgreSQL Extensions documentation currently lists amcheck as supported on PostgreSQL 18 Advanced Edition and states that extensions can be enabled with CREATE EXTENSION.

However, this does not match the actual behavior:

On a DigitalOcean Managed PostgreSQL 18 Advanced Edition cluster, connecting as doadmin and running:

CREATE EXTENSION amcheck;

returns an error. See the attached screenshot.

On a DigitalOcean Managed PostgreSQL 18 Standard Edition cluster, the same command succeeds:

CREATE EXTENSION

See the second attached screenshot.

Please verify the PostgreSQL 18 Advanced Edition extension matrix. If amcheck is not currently installable on Advanced Edition, please remove it from that section and clarify that it is available only on Standard Edition. Alternatively, please enable the extension on Advanced Edition or document the required configuration.

Link to documentation with incorrect information: https://docs.digitalocean.com/products/databases/postgresql/details/supported-extensions/