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From: Ranier Vilela <ranier.vf@gmail.com>
Date: Tue, 7 May 2024 10:28:19 -0300
Message-ID: <CAEudQAowFaOJfBw_=+f1QLvOKE5F4sMNdFPuiuuyyNWXGik6bA@mail.gmail.com>
Subject: Re: CREATE DATABASE with filesystem cloning
To: Pg Hackers <pgsql-hackers@postgresql.org>, "byavuz81@gmail.com" <byavuz81@gmail.com>, 
	Thomas Munro <thomas.munro@gmail.com>, Peter Eisentraut <peter@eisentraut.org>
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Hi,

Nazir Bilal Yavuz <byavuz81(at)gmail(dot)com> wrote:

>Any kind of feedback would be appreciated.

I know it's coming from copy-and-paste, but
I believe the flags could be:
- dstfd = OpenTransientFile(tofile, O_RDWR | O_CREAT | O_EXCL | PG_BINARY);
+ dstfd = OpenTransientFile(tofile, O_CREAT | O_WRONLY | O_TRUNC | O_EXCL |
PG_BINARY);

The flags:
O_WRONLY | O_TRUNC

Allow the OS to make some optimizations, if you deem it possible.

The flag O_RDWR indicates that the file can be read, which is not true in
this case.
The destination file will just be written.

best regards,
Ranier Vilela

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<div dir=3D"ltr"><div>Hi,</div><div><br></div><div>
Nazir Bilal Yavuz &lt;byavuz81(at)gmail(dot)com&gt; wrote:</div><div>
<p>&gt;Any kind of feedback would be appreciated.</p><p>I know it&#39;s com=
ing from copy-and-paste, but<br>I believe the flags could be:<br>- dstfd =
=3D OpenTransientFile(tofile, O_RDWR | O_CREAT | O_EXCL | PG_BINARY);<br>+=
=C2=A0dstfd =3D OpenTransientFile(tofile, O_CREAT | O_WRONLY | O_TRUNC | O_=
EXCL | PG_BINARY);</p>
<pre>The flags:<br>O_WRONLY | O_TRUNC</pre>Allow the OS to make some optimi=
zations, if you deem it possible.</div><div><br></div><div>The flag O_RDWR =
indicates that the file can be read, which is not true in this case.=C2=A0<=
/div><div>The destination file will just be written.</div><div><br></div><d=
iv>best regards,</div><div>Ranier Vilela<br></div></div>

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