Subject: Re: "System roles" mentioned in psql documentation
To: pgsql-docs@lists.postgresql.org
References: <20180823075800.GA30782@paquier.xyz>
 <753d785e-2d9c-16b1-5430-61ce9027cea3@purtz.de>
 <20180824002111.GE30782@paquier.xyz>
From: =?UTF-8?Q?J=c3=bcrgen_Purtz?= <juergen@purtz.de>
Message-ID: <5409a8d0-5c29-3956-bb06-025b82fc3b56@purtz.de>
Date: Fri, 24 Aug 2018 11:40:19 +0200
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On 24.08.2018 02:21, Michael Paquier wrote:

> On Thu, Aug 23, 2018 at 10:53:35AM +0200, Jürgen Purtz wrote:
>> This inconsistency is part of the more general problem that we miss a
>> chapter, where our basic terms like 'database', 'cluster', 'segment',
>> 'catalog', 'schema', ... are explicitly defined.
> You may have a point here, not in the way of reworking entirely the
> documentation, but in the fact that we may want to use "system objects"
> instead of "system roles".  I am not personally sure that it is a better
> improvement than using "default roles", but that's a point to raise.
> --
> Michael

First, the intention of my note was to improve the complete 
documentation by defining the meaning of important terms in a separate 
chapter. The discussion about "system roles" and "default roles" is only 
one of many points where we use terms in a fuzzy way.

Second (and this seems to be the point of your mail), the term "role" is 
loosely described at the beginning of chapter 21 "A role can be thought 
of as either a database user, or ... ". In contrast to this description 
chapter 21.5 and table 21.1. use the term "role" very differently. Here 
it is used in the sense of a "capability", a "right", a "permission", an 
"allowed access" ... . This cumulates in the example at the bottom: 
"GRANT pg_signal_backend TO admin_user;"  What is the "role", the 
"pg_signal_backend" or the "admin_user"?

Kind regards
Jürgen Purtz