This pattern describes options for migrating the ROWID pseudocolumn functionality in Oracle Database to a PostgreSQL database in Amazon Relational Database Service (Amazon RDS) for PostgreSQL, Amazon Aurora PostgreSQL-Compatible Edition, or Amazon Elastic Compute Cloud (Amazon EC2).
In an Oracle database, the ROWID pseudocolumn is a physical address of a row in a table. This pseudocolumn is used to uniquely identify a row even if the primary key isn’t present on a table. PostgreSQL has a similar pseudocolumn called ctid, but it cannot be used as a ROWID. As explained in the PostgreSQL documentation, ctid might change if it’s updated or after every VACUUM process
