From: David Steele <david@pgmasters.net>
To: Nathan Bossart <nathandbossart@gmail.com>
Cc: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Cc: robertmhaas@gmail.com
Cc: masao.fujii@oss.nttdata.com
Cc: pgsql-hackers@postgresql.org
Subject: Re: remove more archiving overhead
Date: Fri, 8 Jul 2022 13:02:51 -0400
Message-ID: <983e1c05-d479-dec3-b96e-0e5e359f5aa7@pgmasters.net> (raw)
In-Reply-To: <20220708165450.GA2356733@nathanxps13>
References: <20220707182251.GA2255242@nathanxps13>
<ba7e11b0-054d-1d26-bafd-7a2bc97f11f7@pgmasters.net>
<20220707220716.GA2258527@nathanxps13>
<20220708.105652.1551158050191356887.horikyota.ntt@gmail.com>
<44dbf5e4-8eec-da56-daba-755128b3723e@pgmasters.net>
<20220708165450.GA2356733@nathanxps13>
On 7/8/22 12:54, Nathan Bossart wrote:
> On Fri, Jul 08, 2022 at 08:20:09AM -0400, David Steele wrote:
>
>> Nathan, I don't see the language about being sure to persist to storage
>> here?
>
> It's here:
> When an archive library encounters a pre-existing file, it may return
> true if the WAL file has identical contents to the pre-existing archive
> and the pre-existing archive is fully persisted to storage.
>
> Since you didn't catch it, I wonder if it needs improvement. At the very
> least, perhaps we should note that one way to do the latter is to persist
> it yourself before returning true, and we could point to basic_archive.c as
> an example. However, I'm hesitant to make these docs too much more
> complicated than they already are. WDYT?
I think I wrote this before I'd had enough coffee. "fully persisted to
storage" can mean many things depending on the storage (Posix, CIFS, S3,
etc.) so I think this is fine. The basic_archive module is there for
people who would like implementation details for Posix.
Regards,
-David
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To: pgsql-hackers@postgresql.org
Cc: david@pgmasters.net, nathandbossart@gmail.com, horikyota.ntt@gmail.com, robertmhaas@gmail.com, masao.fujii@oss.nttdata.com
Subject: Re: remove more archiving overhead
In-Reply-To: <983e1c05-d479-dec3-b96e-0e5e359f5aa7@pgmasters.net>
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