Look into PostgreSQL 10 identity columns #3
Description
PostgreSQL 10, released October 2017, added support for identity columns, an auto-incrementing column type that is frequently used as a primary key. Traditionally, this functionality in PostgreSQL has been idiomatically achieved with the serial numeric type column, but identity columns adhere to the ANSI sql standard and are thus more portable (among other advantages, covered in the links below).
It would be great if the Vapor PostgreSQL Fluent package could support identity columns, if not by default then perhaps manually in a model's migration implementation.
More information:
https://wiki.postgresql.org/wiki/New_in_postgres_10#Identity_Columns
https://blog.2ndquadrant.com/postgresql-10-identity-columns/
https://www.depesz.com/2017/04/10/waiting-for-postgresql-10-identity-columns/
https://www.postgresql.org/docs/10/static/sql-createtable.html