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 1lQtpf-0006cr-Ay for pgsql-novice@arkaria.postgresql.org; Mon, 29 Mar 2021 15:29:35 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.92) (envelope-from ) id 1lQtpc-0005WS-C8 for pgsql-novice@arkaria.postgresql.org; Mon, 29 Mar 2021 15:29:32 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lQtpc-0005WL-3w for pgsql-novice@lists.postgresql.org; Mon, 29 Mar 2021 15:29:32 +0000 Received: from mail-yb1-xb31.google.com ([2607:f8b0:4864:20::b31]) by magus.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1lQtpZ-0004c3-HN for pgsql-novice@postgresql.org; Mon, 29 Mar 2021 15:29:31 +0000 Received: by mail-yb1-xb31.google.com with SMTP id l15so14243238ybm.0 for ; Mon, 29 Mar 2021 08:29:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=0atF91aM2yZSB1Ar3bZPt7CVLa9WQnFdqKrlwcLDzVw=; b=DLyCvbWi5fACDvRjTxcaVZn+kQJIjtFKnzYKz8DYqpf2IOldf+1+EEI8/Cv0tqmqp7 AAMxdyH1wD84tQaI7wlELTN6Qu7RmUPY74C9vUURq9DEaA60JX1LdC5qQqbdUClTZPem D+uMYUUqKc/y2HNCmbY/IIGB5HplVf98TvV0L1eVb/mpYKmDTWRce7GWGBzKMi0nJ4L3 8qcQI9sc2pKpXO4zR4nNpHk/v4nP2nJAYbc7bxUOKDONp29UlIYbf6jK8Fdi5vOB1iB1 +b7MSu16hx744VHrsYhHwWHZ/eObhQNEp+CYA07PilVOcstuITSVFDuxOjNNUw+PtAwI yClg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=0atF91aM2yZSB1Ar3bZPt7CVLa9WQnFdqKrlwcLDzVw=; b=SE0mYgzPFbvJ943xh7ZjrgNAE6ll3RDi7P3EHy2W/2iGDU+X9A8pwpXeHOhpzzsKPE C9nOA9pj4qW5rvlCqbdhlW+nl/OdxBfLvSSiuaD5I3ijyopRHMStkEC9zVGiQphN4thX QbW/eZQQevHMk2kLPD5+iLtBYZm93w21FpynWCyL5/x3D7b1G1+b4g1rU2AQg6fLX6hy KLv2LbRWFB6EYla/7X7fygmiDmN2rLhg6SxuHCQwKAMyb7VquwLXrUu/A8IQABiNg7IT 4ufyVjch5UHGnrZ1CmLkYwDLhKuGl94e2HpMWN3+Gqo7KZTVtat7Cc2FsN0HYrr2Ht3Z 24FA== X-Gm-Message-State: AOAM530LX99mgsibL4GeUeGe9zLY9XZ0SqcQKtCg6AxL2UQIpuz+TPCG Tc9ANJHZ4dseKndCT571I16fIWaIcqIG9NjQ1S07n4RjcsA= X-Google-Smtp-Source: ABdhPJwYp1fNjXBvKWKQ/x7j70bOd7LF8PqM9LsGHcQ3eWoaETaTWQ3/yE6Zpk3MRYpwghXa/6merd2jPPzT3MJPS9s= X-Received: by 2002:a25:ab2f:: with SMTP id u44mr29396047ybi.158.1617031767355; Mon, 29 Mar 2021 08:29:27 -0700 (PDT) MIME-Version: 1.0 From: Greg Rychlewski Date: Mon, 29 Mar 2021 11:27:21 -0400 Message-ID: Subject: shared buffers To: pgsql-novice@postgresql.org Content-Type: multipart/alternative; boundary="0000000000001577c405beae8c70" List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk --0000000000001577c405beae8c70 Content-Type: text/plain; charset="UTF-8" Hi, Will every page touched during a table or index scan, even if it's not going to be used in the final result, be loaded into shared buffers? i.e. if you need to evaluate a filter condition, will it load that page into shared buffers and then evaluate it from there? --0000000000001577c405beae8c70 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi,

Will every page touched during a ta= ble or index scan, even if it's not going to be used in the final resul= t, be loaded into shared buffers?=C2=A0

i.e. if yo= u need to evaluate a filter condition, will it load that page into shared b= uffers and then evaluate it from there?
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