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Reply-To: assam258@gmail.com
From: Henson Choi <assam258@gmail.com>
Date: Fri, 9 Jan 2026 12:15:21 +0900
Message-ID: <CAAAe_zBUd3epVqcDAMVmLDt4-dhxVY5W09+gp5ND_P--b90eeA@mail.gmail.com>
Subject: Re: [PATCH] Add pg_current_vxact_id() function to expose virtual
 transaction IDs
To: Michael Paquier <michael@paquier.xyz>
Cc: Pavlo Golub <pavlo.golub@cybertec.at>, pgsql-hackers@lists.postgresql.org
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2026=EB=85=84 1=EC=9B=94 9=EC=9D=BC (=EA=B8=88) AM 9:25, Michael Paquier <m=
ichael@paquier.xyz>=EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84=B1:

> On Mon, Dec 08, 2025 at 12:09:58PM +0000, Pavlo Golub wrote:
> > Virtual transaction IDs are fundamental to PostgreSQL's transaction
> > tracking,
> > appearing in pg_locks.virtualtransaction, log output via %v placeholder=
,
> and
> > internal transaction management. However, there's currently no direct S=
QL
> > function to retrieve the current VXID, forcing applications to query
> > pg_locks
> > or parse log files to obtain this information.
>
> This is replacing one SQL in a given session by another, as a session
> currently running a transaction can query itself pg_locks and match an
> entry with its own pg_backend_pid().  Hence I don't see the need for
> this function, except simplicity in retrieving a session's state with
> less characters typed at the end?
>

I see this as a tradeoff between minor convenience and negligible
addition cost.

The community should decide whether this tradeoff is worth it.


> Thoughts and opinions from others are welcome.  I'm always OK to be
> outvoted.
> --
> Michael
>

Best regards,
Henson Choi

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<div dir=3D"ltr"><div dir=3D"ltr"><br></div><br><div class=3D"gmail_quote g=
mail_quote_container"><div dir=3D"ltr" class=3D"gmail_attr">2026=EB=85=84 1=
=EC=9B=94 9=EC=9D=BC (=EA=B8=88) AM 9:25, Michael Paquier &lt;<a href=3D"ma=
ilto:michael@paquier.xyz">michael@paquier.xyz</a>&gt;=EB=8B=98=EC=9D=B4 =EC=
=9E=91=EC=84=B1:<br></div><blockquote class=3D"gmail_quote" style=3D"margin=
:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-lef=
t-color:rgb(204,204,204);padding-left:1ex">On Mon, Dec 08, 2025 at 12:09:58=
PM +0000, Pavlo Golub wrote:<br>
&gt; Virtual transaction IDs are fundamental to PostgreSQL&#39;s transactio=
n<br>
&gt; tracking,<br>
&gt; appearing in pg_locks.virtualtransaction, log output via %v placeholde=
r, and<br>
&gt; internal transaction management. However, there&#39;s currently no dir=
ect SQL<br>
&gt; function to retrieve the current VXID, forcing applications to query<b=
r>
&gt; pg_locks<br>
&gt; or parse log files to obtain this information.<br>
<br>
This is replacing one SQL in a given session by another, as a session<br>
currently running a transaction can query itself pg_locks and match an<br>
entry with its own pg_backend_pid().=C2=A0 Hence I don&#39;t see the need f=
or<br>
this function, except simplicity in retrieving a session&#39;s state with<b=
r>
less characters typed at the end?<br></blockquote><div><br></div>I see this=
 as a tradeoff between minor convenience and negligible <br>addition cost.<=
br><br>The community should decide whether this tradeoff is worth it.<br><b=
r><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;borde=
r-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204)=
;padding-left:1ex"><br>
Thoughts and opinions from others are welcome.=C2=A0 I&#39;m always OK to b=
e<br>
outvoted.<br>
--<br>
Michael<br></blockquote><div><br></div>Best regards,<br><div>Henson Choi=C2=
=A0</div><div>=C2=A0</div></div></div>

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