Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nLd5h-00059L-LH for pgsql-hackers@arkaria.postgresql.org; Sun, 20 Feb 2022 03:40:53 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.92) (envelope-from ) id 1nLd5g-0004Qp-A5 for pgsql-hackers@arkaria.postgresql.org; Sun, 20 Feb 2022 03:40:52 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nLd5g-0004PK-0n for pgsql-hackers@lists.postgresql.org; Sun, 20 Feb 2022 03:40:52 +0000 Received: from mail-ed1-x535.google.com ([2a00:1450:4864:20::535]) by makus.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1nLd5b-0005Bp-Gh for pgsql-hackers@lists.postgresql.org; Sun, 20 Feb 2022 03:40:50 +0000 Received: by mail-ed1-x535.google.com with SMTP id h15so5548486edv.7 for ; Sat, 19 Feb 2022 19:40:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bowt-ie.20210112.gappssmtp.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Ny2GfIE9TlsdWiAY08HMquY6soL+ThJCmRdVnh6bX+M=; b=d8OEQIMSQuoOre6pMsdhRPvNaMU5TkfkbeFnKZMfiDsU5yzJyXX5+PHiOvcefmCuPD JHC6qWp3rE+Zplsef0JKNSDVjiy/LUkLOodkdRCyr0fY98c54x+PC8H1g6EDE1RdsSHy In1O/RK6h197u3+NcwaK1Km5pewsfveTiASt+uzTLz9x7yHQSvq9bESjtYVBR1QP4Mbs XQXqlYXbEROylCL2J/t5b6ogbWP8/mXgVIAYE2z66JPEK5plGYyXz/7gSUbDEH/Bw8XH 8dsL0qavx1N0ujGmr1vykWRpSHjn9fFKJLN/WbTsHpS0r4UOmWqwL2bMINsG1FjsJCrf QXqw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Ny2GfIE9TlsdWiAY08HMquY6soL+ThJCmRdVnh6bX+M=; b=AAzMh0I9RUMW2vG846FfGuXid0BUuC3IKlRJTu6Yu38kqACUV6RQGosWi1nCoh0Scz NLHvjG2JtIKikflrKoGW6sQw7cyPYOb5aQZr8D83oPmCsUlR983WTLXWCTXkldbELDCj Salt6X3cswhNsz/Va3UArYfRC5dYGotQzzleNn5hmIzLskzcUG7F7CDkg22/WAip2X04 wjOixDHJKJgNUGpX5nM3EqTrLgiQM4XcfGZqUei+mHuW6i3CNINRCHvEqdHCH7/7fTyW AMB0dx3WNbNLHCUKnawcQiXAm4lfqhLFobO66nu7TMnTz3I9269yISdWFC4Ri3/prTSe Znsg== X-Gm-Message-State: AOAM531YqSgy8bCtlgoG9HTAdjzwRMDc3ifP3/JT4oGMdwhaHnmb74/Q oBCPCYgUgLUY+iQQQI4iUWoeqrPShXvRD7WHdZ73pA== X-Google-Smtp-Source: ABdhPJwRVMF0i5JK+l7AoiltZB43i15HqHgMt8U6M/WnKL5HJkIYktwb1vN572A8BhjZ6E4V+pIbsj0Y+M8XBlwTEgM= X-Received: by 2002:a50:9991:0:b0:410:a3e5:5066 with SMTP id m17-20020a509991000000b00410a3e55066mr15560290edb.49.1645328446204; Sat, 19 Feb 2022 19:40:46 -0800 (PST) MIME-Version: 1.0 References: <20220218221117.ijozsjwaxa6fy5u6@alap3.anarazel.de> <20220220015416.gxnocs4we56ghmj3@alap3.anarazel.de> <20220220030128.sgytb3wccteb3opj@alap3.anarazel.de> <20220220032833.tvdxa3ddfuvu3ezu@alap3.anarazel.de> In-Reply-To: <20220220032833.tvdxa3ddfuvu3ezu@alap3.anarazel.de> From: Peter Geoghegan Date: Sat, 19 Feb 2022 19:40:20 -0800 Message-ID: Subject: Re: Removing more vacuumlazy.c special cases, relfrozenxid optimizations To: Andres Freund Cc: Robert Haas , Masahiko Sawada , PostgreSQL Hackers Content-Type: text/plain; charset="UTF-8" List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk On Sat, Feb 19, 2022 at 7:28 PM Andres Freund wrote: > If the vacuum can get the cleanup lock due to the adversarial patch, the > heap_force_kill() doesn't do anything, because the first item is a > redirect. However if it *can't* get a cleanup lock, heap_force_kill() instead > targets the root item. Triggering the endless loop. But it shouldn't matter if the root item is an LP_REDIRECT or a normal (not heap-only) tuple with storage. Either way it's the root of a HOT chain. The fact that pg_surgery treats LP_REDIRECT items differently from the other kind of root items is just arbitrary. It seems to have more to do with freezing tuples than killing tuples. -- Peter Geoghegan