Amazon Redshift는 PostgreSQL을 기반으로 한다.
https://docs.aws.amazon.com/redshift/latest/dg/c_redshift-and-postgres-sql.html
Amazon Redshift is based on PostgreSQL. Amazon Redshift and PostgreSQL have a number of very important differences that you must be aware of as you design and develop your data warehouse applications.
다만, 몇 가지 중요한 차이점이 있다고 한다.