What is unversion in Aurora CDK construct

Question

When I try to deploy Aurora cluster by using CDK, I read this instruction in this instruction,example is shown as follows. But I have questions, what is The unversioned 'aurora-postgresql' cluster engine. in description of AURORA_POSTGRESQL ? what versions are exactlly set in following construct ?

declare const vpc: ec2.Vpc;

const cluster = new rds.ServerlessCluster(this, 'AnotherCluster', {
  engine: rds.DatabaseClusterEngine.AURORA_POSTGRESQL,
  parameterGroup: rds.ParameterGroup.fromParameterGroupName(this, 'ParameterGroup', 'default.aurora-postgresql10'),
  vpc,
  scaling: {
    autoPause: Duration.minutes(10), // default is to pause after 5 minutes of idle time
    minCapacity: rds.AuroraCapacityUnit.ACU_8, // default is 2 Aurora capacity units (ACUs)
    maxCapacity: rds.AuroraCapacityUnit.ACU_32, // default is 16 Aurora capacity units (ACUs)
  }
});

I also search for how to set Aurora latest versions.

Sorry for inconvenience Thanks

Answer 1

The code is for Aurora serverless, not regular Aurora. For serverless there is usually only one version available, which you can check using the following AWS CLI command:

aws rds describe-db-engine-versions --engine aurora-postgresql --query "DBEngineVersions[?contains(@.SupportedEngineModes, 'serverless')].EngineVersion" 

In my case this returns 10.14.