Feedback-ID: ia2694551:Fastmail
Date: Mon, 24 Apr 2023 18:04:19 +0200
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Ajit Awekar <ajit.awekar@enterprisedb.com>,
	pgsql-hackers@lists.postgresql.org,
	Rushabh Lathia <rushabh.lathia@enterprisedb.com>,
	Jeevan Chalke <jeevan.chalke@enterprisedb.com>
Subject: Re: Memory leak in CachememoryContext
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On 2023-Apr-24, Tom Lane wrote:

> I wrote:
> > Alvaro Herrera <alvherre@alvh.no-ip.org> writes:
> >> Hmm, we can leave it unused in our code, but it still needs to be
> >> initialized to some valid memory context anyway; otherwise hypothetical
> >> code that uses it would still crash.
> 
> > I think we want that to happen, actually, because it's impossible
> > to guess what such hypothetical code needs the context to be.
> 
> I guess we could have the back branches continue to create a
> shared_cast_context and just not use it in core.  Seems rather
> expensive for a very hypothetical compatibility measure, though.

I think a session-long memory leak is not so bad, compared to a possible
crash.  However, after looking at the code again, as well as pldebugger
and plpgsql_check, I agree that there's no point in doing anything other
than keeping the field there.

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/
"Hay dos momentos en la vida de un hombre en los que no debería
especular: cuando puede permitírselo y cuando no puede" (Mark Twain)