Re: vacuum as flags in PGPROC

From: Heikki Linnakangas <heikki(at)enterprisedb(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Alvaro Herrera <alvherre(at)commandprompt(dot)com>, Patches <pgsql-patches(at)postgresql(dot)org>
Subject: Re: vacuum as flags in PGPROC
Date: 2007-10-24 15:57:58
Message-ID: 471F6B86.8090209@enterprisedb.com
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Tom Lane wrote:
> Heikki Linnakangas <heikki(at)enterprisedb(dot)com> writes:
>> Alvaro Herrera wrote:
>>> I did it that way (i.e. added locking) and then realized that it
>>> shouldn't really be a problem, because the only one who can be setting
>>> vacuum flags is the process itself. Other processes can only read the
>>> flags.
>
>> It would still be a problem if there was any other fields that were
>> updated by other processes, adjacent to the vacuum flags. I don't think
>> that's the case, however.
>
> Well, that may not be the case today, but it still seems like an
> assumption that will come back to bite us someday. And can you imagine
> trying to debug a misbehavior like that? It's really not worth the risk,
> given how seldom these flags will be changed.

Oh, I totally agree. I wasn't trying to argue to the contrary.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com

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