Subject: Re: drop postmaster symlink

From: Peter Eisentraut <[email-masked]>
Date: Thu, 12 Jan 2023 18:00:59 +0100

On 23.11.22 21:32, Joe Conway wrote:
>> Yeah. Also, I don't think it's generally too hard to find the parent
>> process anyway, because at least on my system, the other ones end up
>> with ps display that looks like "postgres: logical replication
>> launcher" or whatever. The main process doesn't set the ps status
>> display, so that's the only one that shows a full path to the
>> executable in the ps status, which is how I usually spot it. That has
>> the advantage that it doesn't matter which name was used to launch it,
>> too.

I think it is a problem that one of the most widely used packagings of 
PostgreSQL uses techniques that are directly contradicting the 
PostgreSQL documentation and are also inconsistent with other widely 
used packagings.  Users might learn this "trick" but then can't reuse it 
elsewhere, and conversely those who come from other systems might not be 
able to reuse their scripts.  That is annoying.

> FWIW, the reason I took note of the postmaster symlink in the first 
> place a few years ago was because selinux treats execution of programs 
> from symlinks differently than from actual files.

This is another such case, where knowledge about selinux configuration 
cannot be transported between Linux distributions.

I almost feel that issues like this make a stronger case for removing 
the postmaster symlink than if it hadn't actually been in use, since the 
removal would serve to unify the landscape for the benefit of users.