Subject: Re: Get memory contexts of an arbitrary backend process
To: torikoshia <torikoshia@oss.nttdata.com>,
 Georgios Kokolatos <gkokolatos@protonmail.com>
Cc: pgsql-hackers@postgresql.org
References: <0271f440ac77f2a4180e0e56ebd944d1@oss.nttdata.com>
 <270ec80dbbebfb5c6f2b9fdd7a7858b5@oss.nttdata.com>
 <160502083340.7362.4386116585349115146.pgcf@coridan.postgresql.org>
 <064d510f2d33edc37dfd6b8f3b6bd30e@oss.nttdata.com>
From: Fujii Masao <masao.fujii@oss.nttdata.com>
Message-ID: <d42d3186-d647-9af4-7c1c-d6ffca8bff40@oss.nttdata.com>
Date: Thu, 3 Dec 2020 10:10:06 +0900
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On 2020/11/16 19:58, torikoshia wrote:
> On 2020-10-28 15:32, torikoshia wrote:
>> On 2020-10-23 13:46, Kyotaro Horiguchi wrote:
> 
>>> I think we might need to step-back to basic design of this feature
>>> since this patch seems to have unhandled corner cases that are
>>> difficult to find.
> 
> I've written out the basic design below and attached
> corresponding patch.

I'm starting to study how this feature behaves. At first, when I executed
the following query, the function never returned. ISTM that since
the autovacuum launcher cannot respond to the request of memory
contexts dump, the function keeps waiting infinity. Is this a bug?
Probably we should exclude non-backend proceses from the target
processes to dump? Sorry if this was already discussed.

     SELECT pg_get_backend_memory_contexts(pid) FROM pg_stat_activity;


Regards,

-- 
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION