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Date: Sun, 12 Nov 2023 09:09:27 -0500
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Subject: Re: pg_basebackup check vs Windows file path limits
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To: Alexander Lakhin <exclusion@gmail.com>,
 Daniel Gustafsson <daniel@yesql.se>
Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>
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From: Andrew Dunstan <andrew@dunslane.net>
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On 2023-11-11 Sa 12:00, Alexander Lakhin wrote:
> 11.11.2023 18:18, Andrew Dunstan wrote:
>>
>> Hmm, maybe we should be using File::Copy::move() instead of rename(). 
>> The docco for that says:
>>
>>          If possible, move() will simply rename the file. Otherwise, it
>>          copies the file to the new location and deletes the original. If an
>>          error occurs during this copy-and-delete process, you may be left
>>          with a (possibly partial) copy of the file under the destination
>>          name.
>
> Unfortunately, I've stumbled upon inability of File::Copy::move()
> to move directories across filesystems, exactly as described here:
> https://stackoverflow.com/questions/17628039/filecopy-move-directories-accross-drives-in-windows-not-working
>
> (I'm sorry for not looking above rename() where this stated explicitly:
> # On Windows use the short location to avoid path length issues.
> # Elsewhere use $tempdir to avoid file system boundary issues with moving.
> So this issue affects Windows only.)
>
>

*sigh*

A probable workaround is to use a temp directory on the same device the 
test is building on. Just set it up and set your environment TEMPDIR to 
point to it, and I think it will be OK (i.e. I havent tested it).

But that doesn't mean I'm not searching for a better solution. Maybe 
Alvaro's suggestion nearby will help.


cheers


andrew


--
Andrew Dunstan
EDB:https://www.enterprisedb.com

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    <p><br>
    </p>
    <div class="moz-cite-prefix">On 2023-11-11 Sa 12:00, Alexander
      Lakhin wrote:<br>
    </div>
    <blockquote type="cite"
      cite="mid:6aa7c5a0-a4c8-dd2c-3a99-946eb7f23155@gmail.com">
      <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
      <div class="moz-cite-prefix">11.11.2023 18:18, Andrew Dunstan
        wrote:<br>
      </div>
      <blockquote type="cite"
        cite="mid:9293e623-1d5e-0bd3-9b61-6129821b6f42@dunslane.net">
        <meta http-equiv="Content-Type" content="text/html;
          charset=UTF-8">
        <p>Hmm, maybe we should be using File::Copy::move() instead of
          rename(). The docco for that says:</p>
        <pre>        If possible, move() will simply rename the file. Otherwise, it
        copies the file to the new location and deletes the original. If an
        error occurs during this copy-and-delete process, you may be left
        with a (possibly partial) copy of the file under the destination
        name.</pre>
      </blockquote>
      <br>
      Unfortunately, I've stumbled upon inability of File::Copy::move()<br>
      to move directories across filesystems, exactly as described here:<br>
      <a class="moz-txt-link-freetext"
href="https://stackoverflow.com/questions/17628039/filecopy-move-directories-accross-drives-in-windows-not-working"
        moz-do-not-send="true">https://stackoverflow.com/questions/17628039/filecopy-move-directories-accross-drives-in-windows-not-working</a><br>
      <br>
      (I'm sorry for not looking above rename() where this stated
      explicitly:<br>
      # On Windows use the short location to avoid path length issues.<br>
      # Elsewhere use $tempdir to avoid file system boundary issues with
      moving.<br>
      So this issue affects Windows only.)<br>
      <br>
      <br>
    </blockquote>
    <p><br>
    </p>
    <p>*sigh*</p>
    <p>A probable workaround is to use a temp directory on the same
      device the test is building on. Just set it up and set your
      environment TEMPDIR to point to it, and I think it will be OK
      (i.e. I havent tested it).<br>
    </p>
    <p>But that doesn't mean I'm not searching for a better solution.
      Maybe Alvaro's suggestion nearby will help.</p>
    <p><br>
    </p>
    <p>cheers</p>
    <p><br>
    </p>
    <p>andrew<br>
    </p>
    <p><br>
    </p>
    <pre class="moz-signature" signature-switch-id="d0437855-2267-4610-80b3-83167ec45b0b" cols="72">--
Andrew Dunstan
EDB: <a class="moz-txt-link-freetext" href="https://www.enterprisedb.com">https://www.enterprisedb.com</a>
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