Received: from malur.postgresql.org ([217.196.149.56])
	by arkaria.postgresql.org with esmtps  (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
	(Exim 4.94.2)
	(envelope-from <pgsql-hackers-owner+archive@lists.postgresql.org>)
	id 1sjUNa-001AzK-14
	for pgsql-hackers@arkaria.postgresql.org; Thu, 29 Aug 2024 01:55:18 +0000
Received: from localhost ([127.0.0.1] helo=malur.postgresql.org)
	by malur.postgresql.org with esmtp (Exim 4.94.2)
	(envelope-from <pgsql-hackers-owner+archive@lists.postgresql.org>)
	id 1sjUNX-00D7EW-6w
	for pgsql-hackers@arkaria.postgresql.org; Thu, 29 Aug 2024 01:55:15 +0000
Received: from makus.postgresql.org ([2001:4800:3e1:1::229])
	by malur.postgresql.org with esmtps  (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
	(Exim 4.94.2)
	(envelope-from <guofenglinux@gmail.com>)
	id 1sjUNW-00D7EN-QG
	for pgsql-hackers@lists.postgresql.org; Thu, 29 Aug 2024 01:55:15 +0000
Received: from mail-yw1-x1130.google.com ([2607:f8b0:4864:20::1130])
	by makus.postgresql.org with esmtps  (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
	(Exim 4.94.2)
	(envelope-from <guofenglinux@gmail.com>)
	id 1sjUNR-001w9r-1g
	for pgsql-hackers@lists.postgresql.org; Thu, 29 Aug 2024 01:55:14 +0000
Received: by mail-yw1-x1130.google.com with SMTP id 00721157ae682-68d30057ae9so1792657b3.1
        for <pgsql-hackers@lists.postgresql.org>; Wed, 28 Aug 2024 18:55:08 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=gmail.com; s=20230601; t=1724896508; x=1725501308; darn=lists.postgresql.org;
        h=content-transfer-encoding:cc:to:subject:message-id:date:from
         :in-reply-to:references:mime-version:from:to:cc:subject:date
         :message-id:reply-to;
        bh=nl8MyUAcYRZ5mAfcOc/nqv36c4/tQ1BIDXXHgkr/HX8=;
        b=gnkLf7VCHkI2eGugtLw948RDQaX4zWgYJ5JX38+pgPzs6Bg2amZUdlHez8/BwZIaYw
         nJNbnD5A24aNZP7HfAzaZsh75Frlk27831aKr3jXbp8criE+KYJXhR5F/o8z2XPNODJe
         Ls+0zLzP5UnL5lnd/3WkIWUhUA5AW04UnUmMKk2Cc9zpMN92qDXVZtqIVtRzkpVBmBKK
         Jyo0B7RnjUVEhJZnbcmieK6r+Oj0LaBLvFfNiIMqdHULUwBCdDi22q3VqMyWCNyz1JLI
         Rkgq7k4M+0p8ZVlTIol+IYB/YKlqar/ZWakubc/w+ppmaaFUP+YagNIy/xHppU/OyXg9
         pO6A==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=1e100.net; s=20230601; t=1724896508; x=1725501308;
        h=content-transfer-encoding:cc:to:subject:message-id:date:from
         :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc
         :subject:date:message-id:reply-to;
        bh=nl8MyUAcYRZ5mAfcOc/nqv36c4/tQ1BIDXXHgkr/HX8=;
        b=GU12dYdePDjRkTnExgfxJyC1kR3E+rklTJWSzpB9f2C3SrJ3idg+lNoubEIakHlJK8
         9rfBuY3J60E1PuWxpUBeSgQfkdZLQf0WFtXShK1ahH7M1T+buwFDtucQytWdjmCOnZVm
         J+yi9sQcPRYEAM7wwFF9yAe7P9WeJa/tWX9dBh6iRaN+uwaVkdk/lxg96Ga2yW/EQ4Qx
         cmTs2347R5rZ9gRiKLMOyAbCoPdcA6AdjgMMMI7+jjgh8vgy3WxcndK+cXiDdWqSjLSp
         2m6rAbtN9vh3sk8K+2InkZ452clhxTLo7TilDOB1TS54luj1xKtMmehCcVf61ge2Rz7H
         wpEw==
X-Forwarded-Encrypted: i=1; AJvYcCUkiSIRKyB+RzCaOrNxku941k9dy7YtRtw+kZN5V4s7BcZH7cRMRMvPmyopwUUYjmQj+Mbuinx7XWI6kSx3@lists.postgresql.org
X-Gm-Message-State: AOJu0YweyEt0gd3YhzxzGg0uj+YEb8uGCfIOYGpj1eTqTbUTWDuvctxi
	LBpSDj66e7Qxb+rbSC3dCWm616aKJHJdgUPtzJfNaM7b4I/0Srn1lxSxoaTQBvh6ilCyt5CWc0O
	10tvYJJhK2epC+Hz45MW2wnofUho=
X-Google-Smtp-Source: AGHT+IG2oVkN9hyotWX5x97gs516M5Pkl/uo1fXsZwT/BJy0sjth3rZmBMGNtu/3zUJc16Lb3s9Snvo6i012BABVBdk=
X-Received: by 2002:a05:690c:3204:b0:646:7b75:5c2c with SMTP id
 00721157ae682-6d27620b435mr12284077b3.16.1724896508025; Wed, 28 Aug 2024
 18:55:08 -0700 (PDT)
MIME-Version: 1.0
References: <CALNXOfqDr5jVRZHThyXyNftDuezjxOJB1mqw=4x1T8YBibi6uw@mail.gmail.com>
 <CAG1ps1w61XD1LxUf3EBCZ=VR3S_orRj_dk6cxmO5KusBVyrgMg@mail.gmail.com>
 <CAAvG1pChk3W9MWkK-_JPyUdThSoJhv4MueH5i8cZS2T_HUP5dA@mail.gmail.com>
 <CAG1ps1xvnTZceKK24OUfMKLPvDP2vjT-d+F2AOCWbw_v3KeEgg@mail.gmail.com>
 <2962669.1724722813@sss.pgh.pa.us> <CAApHDvpRxyw1G2HVkA=PM5Uqh59moOFqPXyMTsEDUadKo2fQTA@mail.gmail.com>
 <2965760.1724724227@sss.pgh.pa.us> <CAApHDvoQRoKHNfTaw+Sn=bZGKVmn8W-5yBPGP7+98mWJz5A9uQ@mail.gmail.com>
 <3104695.1724775341@sss.pgh.pa.us> <3147330.1724795532@sss.pgh.pa.us>
 <CAApHDvp1mue1a5fdfsa2z2mAS6v2d9+kxMzxH7GhAiC0Z7o8Mw@mail.gmail.com>
 <3156371.1724800521@sss.pgh.pa.us> <3159017.1724801876@sss.pgh.pa.us>
 <CAApHDvr2v7iwMUsCQKxUPSSzTGuBOx1_e0hyEA8VLy1or35JVA@mail.gmail.com>
 <CAMbWs49gVdBxrjvz82Tqs9UL+ZDNV5cx85ZURhfxUaz-0wz-pQ@mail.gmail.com> <3478841.1724878067@sss.pgh.pa.us>
In-Reply-To: <3478841.1724878067@sss.pgh.pa.us>
From: Richard Guo <guofenglinux@gmail.com>
Date: Thu, 29 Aug 2024 09:54:57 +0800
Message-ID: <CAMbWs4-na1ynWwcanzQL85SyjgQ_QfNoxJ3vp3DH14iOtYiQ6g@mail.gmail.com>
Subject: Re: Significant Execution Time Difference Between PG13.14 and PG16.4
 for Query on information_schema Tables.
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: David Rowley <dgrowleyml@gmail.com>, nikhil raj <nikhilraj474@gmail.com>, 
	pgsql-hackers@lists.postgresql.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
List-Id: <pgsql-hackers.lists.postgresql.org>
List-Help: <https://lists.postgresql.org/manage/>
List-Subscribe: <https://lists.postgresql.org/manage/>
List-Post: <mailto:pgsql-hackers@lists.postgresql.org>
List-Owner: <mailto:pgsql-hackers-owner@lists.postgresql.org>
List-Archive: <https://www.postgresql.org/list/pgsql-hackers>
Archived-At: <https://www.postgresql.org/message-id/CAMbWs4-na1ynWwcanzQL85SyjgQ_QfNoxJ3vp3DH14iOtYiQ6g%40mail.gmail.com>
Precedence: bulk

On Thu, Aug 29, 2024 at 4:47=E2=80=AFAM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> In the meantime, I think this test case is mighty artificial,
> and it wouldn't bother me any to just take it out again for the
> time being.

Yeah, I think we can remove the 't1.two+t2.two' test case if we go
with your proposed patch to address this performance regression.

Thanks
Richard