Feedback-ID: i0fe9450f:Fastmail
Date: Wed, 14 Feb 2024 16:23:38 +0900
From: Michael Paquier <michael@paquier.xyz>
To: torikoshia <torikoshia@oss.nttdata.com>
Cc: Melih Mutlu <m.melihmutlu@gmail.com>,
	Andres Freund <andres@anarazel.de>,
	Stephen Frost <sfrost@snowman.net>,
	PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: Parent/child context relation in pg_get_backend_memory_contexts()
Message-ID: <ZcxqerWx_jDZgtDQ@paquier.xyz>
References: <CAGPVpCThLyOsj3e_gYEvLoHkr5w=tadDiN_=z2OwsK3VJppeBA@mail.gmail.com>
 <CAGPVpCRNGd4V6MsxOttDZG4Hbf-4c1rrQKL4CsLyhaSY4sNkjA@mail.gmail.com>
 <20231012162309.4wmc2nb5tkt6pzml@awork3.anarazel.de>
 <CAGPVpCQjpcU=T9wtzWX+dU5LkXnPc2OBqNHoZmKHWFFH8YL7ZQ@mail.gmail.com>
 <2f34c14847fc03752f0bca7d97aeae27@oss.nttdata.com>
 <CAGPVpCT0xuoBvx0=myzKYmv02bQ64BC96Z_-dVKckH3++Jg+DA@mail.gmail.com>
 <f94acf68cee0483aade20a219f127a6c@oss.nttdata.com>
 <CAGPVpCSvNDXy1vDTjgGVCOCAndQ6iB_LVyjb1GNATEqdx8zLHw@mail.gmail.com>
 <18d210bb7010f87cdb0019fa846d45ea@oss.nttdata.com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
	protocol="application/pgp-signature"; boundary="WOnxPxxYRPOcCzw9"
Content-Disposition: inline
In-Reply-To: <18d210bb7010f87cdb0019fa846d45ea@oss.nttdata.com>
Archived-At: <https://www.postgresql.org/message-id/ZcxqerWx_jDZgtDQ%40paquier.xyz>
Precedence: bulk


--WOnxPxxYRPOcCzw9
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline

On Fri, Jan 19, 2024 at 05:41:45PM +0900, torikoshia wrote:
> We already have additional description below the table which explains each
> column of the system view. For example pg_locks:
> https://www.postgresql.org/docs/devel/view-pg-locks.html

I was reading the patch, and using int[] as a representation of the
path of context IDs up to the top-most parent looks a bit strange to
me, with the relationship between each parent -> child being
preserved, visibly, based on the order of the elements in this array
made of temporary IDs compiled on-the-fly during the function
execution.  Am I the only one finding that a bit strange?  Could it be
better to use a different data type for this path and perhaps switch
to the names of the contexts involved?

It is possible to retrieve this information some WITH RECURSIVE as
well, as mentioned upthread.  Perhaps we could consider documenting
these tricks?
--
Michael

--WOnxPxxYRPOcCzw9
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----
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=Mvcp
-----END PGP SIGNATURE-----

--WOnxPxxYRPOcCzw9--