=?UTF-8?B?RWzDrWFzIERhdmlk?= <elias(dot)moreno(dot)tec(at)gmail(dot)com> writes:
> By any change, does the following query have an "order by" by default when
> omitted?:
> select datname from pg_database;
No. No SQL query ever has a "default" order by.
> I executed that query against one of my servers and while looking at the
> names it seems complety random, the order is always the same, for instance:
An unqualified query is typically going to result in a sequential scan
of the table, so what you're seeing is the current physical order of the
tuples. This might change after adding/deleting/changing the properties
of a database.
regards, tom lane