"David G. Johnston" <david.g.johnston@gmail.com> writes: > On Tue, Apr 15, 2025 at 11:20 AM Adrian Klaver <adrian.klaver@aklaver.com> > wrote: >> If what you say is true why does initdb lack an option to not create >> them on creating a cluster?
> By creating the initial three databases the system is more usable due to > having established conventions. They are conventional databases, not > system ones.
Precisely. For example, the only reason for the "postgres" database to exist is so that there is a reasonable default database for clients to connect to. If we didn't have it we'd need some other convention. (Indeed, we used to not have it, and back then the default client behavior was usually to connect to template1. That led to people creating random junk in template1 and then being surprised when CREATE DATABASE copied it into new databases.)
Interesting history. I've always interpreted the "postgres" database as being the system database, but now I know it's not.
