Re: free space map and visibility map

From: Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com>
To: Robert Haas <robertmhaas(at)gmail(dot)com>
Cc: Jeff Janes <jeff(dot)janes(at)gmail(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: free space map and visibility map
Date: 2017-03-21 17:15:26
Message-ID: CAD21AoAq2YHs3MvSky6TxX1oKqyiPwUphdSa2sJCab_V4ci4VQ@mail.gmail.com
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On Mon, Mar 20, 2017 at 11:28 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Sat, Mar 18, 2017 at 5:42 PM, Jeff Janes <jeff(dot)janes(at)gmail(dot)com> wrote:
>> Isn't HEAP2_CLEAN only issued before an intended HOT update? (Which then
>> can't leave the block as all visible or all frozen). I think the issue is
>> here is HEAP2_VISIBLE or HEAP2_FREEZE_PAGE. Am I reading this correctly,
>> that neither of those ever update the FSM, regardless of FPI?
>
> Yes, updates to the FSM are never logged. Forcing replay of
> HEAP2_FREEZE_PAGE to update the FSM might be a good idea.
>

I think I was missing something. I imaged your situation is that FPI
is replayed during crash recovery after the crashed server vacuums the
page and marked it as all-frozen. But this situation is also resolved
by that solution.

Regards,

--
Masahiko Sawada
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center

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