> > By creating the initial three databases the system is more usable due to > having established conventions. They are conventional databases, not > system ones.
The bottom line is the Postgres project has built an infrastructure around those names that the community is plugged into.
So, the answer is no, there is no dedicated pg_database column to identify the system/conventional databases created by initdb. They are identified by name. You must know from documentation or experience that they are "postgres", "template1" and "template0".
Pick whichever of "system" or "convention" or some other word makes you happy to categorize those three databases. Though I suggest "the initdb" databases since neither of the other terms is used anywhere in the documentation.
