How to know the size of data stored in a Amazon aurora postgres serverless V2 DB

Hello.

As far as I can see from the document below, it may not be possible to check the size from CloudWatch metrics.
https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/Aurora.AuroraMonitoring.Metrics.html

It is unknown whether it can be used with Aurora PostgreSQL Serverless v2, but if you can execute the following SQL, you can check the database size.
This is SQL that can be executed with regular PostgreSQL.

SELECT pg_database_size(datname) AS db_size, pg_size_pretty(pg_database_size(datname)) AS db_size_h, datname FROM pg_database ORDER BY db_size DESC;