From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Andres Freund <andres@anarazel.de>
Cc: pgsql-hackers@postgresql.org <pgsql-hackers@postgresql.org>
Cc: Amit Kapila <amit.kapila16@gmail.com>
Subject: Re: Why are we PageInit'ing buffers in RelationAddExtraBlocks()?
Date: Wed, 19 Dec 2018 19:39:33 -0500
Message-ID: <13071.1545266373@sss.pgh.pa.us> (raw)
In-Reply-To: <CA+TgmoaJ67VCefuhkd0fdJiWb64bqBtkbZazbVm6a0wimY0fRQ@mail.gmail.com>
References: <20181219083945.6khtgm36mivonhva@alap3.anarazel.de>
<CA+TgmoZRwKbf6q7TXEpwMX_vdjfeGEKudR8mofnmTwZg6O9=kg@mail.gmail.com>
<20181219223736.4k2lhqoj34aaxj3m@alap3.anarazel.de>
<CA+TgmoaJ67VCefuhkd0fdJiWb64bqBtkbZazbVm6a0wimY0fRQ@mail.gmail.com>
Robert Haas <robertmhaas@gmail.com> writes:
> On Wed, Dec 19, 2018 at 5:37 PM Andres Freund <andres@anarazel.de> wrote:
>> What's gained by the logic of emitting that warning in VACUUM after a
>> crash? I don't really see any robustness advantages in it.
> I don't know. I am just normally reluctant to change things
> precipitously that are of long tenure.
Me too, but I think Andres has a point here. Those warnings in VACUUM
are ancient, probably predating the introduction of WAL :-(. At the
time there was good reason to be suspicious of zeroed pages in tables.
Now, though, we have (what we think is) a bulletproof crash recovery
procedure in which possibly-zeroed pages are to be expected; so we're
just causing users unnecessary alarm by warning about them. I think
it's reasonable to, if not remove the messages entirely, at least
downgrade them to a low DEBUG level.
regards, tom lane
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To: pgsql-hackers@postgresql.org
Cc: tgl@sss.pgh.pa.us, robertmhaas@gmail.com, andres@anarazel.de, amit.kapila16@gmail.com
Subject: Re: Why are we PageInit'ing buffers in RelationAddExtraBlocks()?
In-Reply-To: <13071.1545266373@sss.pgh.pa.us>
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