Sql has never been good at handling dynamic columns — it can easily process tables with a fixed number of columns, but dynamic column handling has always been a challenge...
You might already be aware that Postgres updates the process title of all its running processes. For example, this is a Debian Linux ps display for an idle Postgres server...
Object Identifiers (oids) were added to Postgres as a way to uniquely identify database objects, e.g. rows, tables, functions, etc. It is part of Postgres's object-relational heritage.
