From: Tom Lane <tgl@sss.pgh.pa.us>
To: "David G. Johnston" <david.g.johnston@gmail.com>
cc: Alejandro Burne <adburne@gmail.com>,
        "pgsql-bugs@lists.postgresql.org" <pgsql-bugs@lists.postgresql.org>
Subject: Re: Visibility of a local variable
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Comments: In-reply-to "David G. Johnston" <david.g.johnston@gmail.com>
	message dated "Tue, 04 Jun 2024 09:01:56 -0700"
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Date: Tue, 04 Jun 2024 13:05:57 -0400
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"David G. Johnston" <david.g.johnston@gmail.com> writes:
> On Monday, June 3, 2024, Alejandro Burne <adburne@gmail.com> wrote:
>> A local variable, created within a transaction, continues to persist
>> (without value) after the transaction has ended.

> This is under-documented but at present there is no plan to change this
> long-standing behavior, just document it better.

Keep in mind that this entire behavior (ie the ability to create GUCs
not declared in the C code) is an undocumented abuse of the GUC
system.  We probably can't get rid of it at this late date, but
we're very unlikely to make any incompatible changes in the behavior.

			regards, tom lane