Re: [PATCH] Atomic pgrename on Windows

On 1/11/20 5:13 PM, Alexander Korotkov wrote:
> On Tue, Jan 7, 2020 at 11:04 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> "If the link named by the new argument exists and the file's link
> count becomes 0 when it is removed and no process has the file open,
> the space occupied by the file shall be freed and the file shall no
> longer be accessible. If one or more processes have the file open when
> the last link is removed, the link shall be removed before rename()
> returns, but the removal of the file contents shall be postponed until
> all references to the file are closed."
>
> But issue is that on Windows POSIX rename() is kind of impossible to
> implement. And I suspect other platforms may have issues too.
>
> Regarding "pg_stat_tmp/global.stat", which is a problem in particular
> case, we may evade file renaming altogether. Instead, we may
> implement shared-memory counter for filename. So, instead of
> renaming, new reads will just come to new file.

I tend to agree with Tom on the question of portability. But it seems
upthread we have determined that this can't be sensibly isolated into a
Windows-specific rename() function.

Does anyone have any further ideas? If not I feel like this patch is
going to need to be RWF again.

Regards,
--
-David
david(at)pgmasters(dot)net