Subject: Re: Unexpected "shared memory block is still in use"
To: Tom Lane <tgl@sss.pgh.pa.us>
References: <22224.1557340366@sss.pgh.pa.us>
 <20190509055414.GB1066859@rfd.leadboat.com> <2663.1557409654@sss.pgh.pa.us>
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Cc: Noah Misch <noah@leadboat.com>, pgsql-hackers@lists.postgresql.org
From: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
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Date: Thu, 5 Sep 2019 14:28:08 +0200
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On 2019-09-04 16:59, Tom Lane wrote:
>> A related point, perhaps we should change the key printed into
>> postmaster.pid to be in hexadecimal format ("0x08x") so that it matches
>> what ipcs prints.
> Hmm, that depends on whose ipcs you use :-(.  A quick survey
> of my machines says it's
> 
>                 key     shmid
> 
> Linux:          hex     decimal
> FreeBSD:        decimal decimal
> NetBSD:         decimal decimal
> OpenBSD:        decimal decimal
> macOS:          hex     decimal
> HPUX:           hex     (not printed)
> 
> There's certainly room to argue that hex+decimal is most popular,
> but I'm not sure that that outweighs possible compatibility issues
> from changing postmaster.pid contents.  (Admittedly, it's not real
> clear that anything would be paying attention to the shmem key,
> so maybe there's no compatibility issue.)

Let's just leave it decimal then.  At least then it's easier to compare
it to ls -i output.

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services