Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1iz4v4-0005Tc-31 for pgsql-hackers@arkaria.postgresql.org; Tue, 04 Feb 2020 20:35:38 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1iz4v1-0000Ze-Un for pgsql-hackers@arkaria.postgresql.org; Tue, 04 Feb 2020 20:35:35 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1iz4v1-0000ZW-La for pgsql-hackers@lists.postgresql.org; Tue, 04 Feb 2020 20:35:35 +0000 Received: from smtp03.optiver.com ([195.246.114.70]) by magus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1iz4uv-0007pc-12 for pgsql-hackers@postgresql.org; Tue, 04 Feb 2020 20:35:35 +0000 Received: from pps.filterd (smtp03.optiver.com [127.0.0.1]) by smtp03.optiver.com (8.16.0.27/8.16.0.27) with SMTP id 014KY7YG017031; Tue, 4 Feb 2020 21:34:10 +0100 Received: from opammb0561.comp.optiver.com (opammb0561.comp.optiver.com [10.131.160.1]) by smtp03.optiver.com with ESMTP id 2xvyt91taj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT); Tue, 04 Feb 2020 21:34:10 +0100 Received: from opammb0561.comp.optiver.com (10.131.160.1) by opammb0561.comp.optiver.com (10.131.160.1) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 4 Feb 2020 21:34:09 +0100 Received: from opammb0561.comp.optiver.com ([fe80::2de5:b7b8:fa63:4be5]) by opammb0561.comp.optiver.com ([fe80::2de5:b7b8:fa63:4be5%17]) with mapi id 15.00.1473.003; Tue, 4 Feb 2020 21:34:09 +0100 From: Floris Van Nee To: Dmitry Dolgov <9erthalion6@gmail.com> CC: Peter Geoghegan , Jesper Pedersen , David Rowley , Tomas Vondra , Kyotaro Horiguchi , Alvaro Herrera , "Thomas Munro" , James Coleman , Rafia Sabih , Jeff Janes , "Bhushan Uparkar" , PostgreSQL-development , Alexander Korotkov Thread-Topic: Index Skip Scan [External] Thread-Index: AQHV0WvkZ26+d70o+UG0IzFaaYH0Qaf+RewAgABIWbCADOoRgIAAGMjm Date: Tue, 4 Feb 2020 20:34:09 +0000 Message-ID: <5be025f30d8e45cda167c58b5d5e72d2@opammb0561.comp.optiver.com> References: <1e59d800b38141c5af2ad3a64cf9758e@opammb0562.comp.optiver.com> <802e46fa-dc2c-4c32-e55b-884e04aa7f12@redhat.com> <20200121160942.eu4bvbu46nt223ug@localhost> <20200122160441.ograupmzyytde2mi@localhost> <1579713885361.64964@Optiver.com> <20200122213603.ndlm6t4ryivdwxs7@localhost> <20200127103016.ieflsboqveb6iduc@localhost> ,<20200204200205.ip5c2mzy3i2okqey@localhost> In-Reply-To: <20200204200205.ip5c2mzy3i2okqey@localhost> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.131.160.182] x-tm-as-product-ver: SMEX-14.0.0.1158-8.5.1020-25212.002 x-tm-as-result: No-10--3.372100-8.000000 x-tmase-matchedrid: O/y65JfDwwvuo96mfIBuopzEHTUOuMX33dCmvEa6IiFJkYDIfDuRnwQ9 n8U23GDf4hPEX6z++9z2BVCy1Jdixfve3kImqG8Fo1Ph4mwugys7F3ZcdQmMK8z/SxKo9mJ4XRq MxbM7tL0x5PCCySkNZV8Ayiud+qfyoOfCjp20fzmeAiCmPx4NwJwhktVkBBrQxq9PbUOwsP9QSF bL1bvQASdET58jp62SLEHu+X3zfUItNew6y2C4faCwQZHZfciJ7a9QJ5s6hejj3NTsPC1QtqTfc lLRWcTJz8uIuy+/yhmgj7U/yl5T6z+LCtvvP/LQ3uEfKV2g8rcJ7ceEs2TdsNM1B0UCKafepX+y yqxcPsfU6uln4S19ow== x-tm-as-user-approved-sender: Yes x-tm-as-user-blocked-sender: No x-tmase-result: 10--3.372100-8.000000 x-tmase-version: SMEX-14.0.0.1158-8.5.1020-25212.002 x-tm-snts-smtp: CC030FCDF4ACD6A379E333EE6767B59F5E59EC0AE6DA7885B03EF5D3BE109BCB2000:8 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: RE: Index Skip Scan X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2020-02-04_08:,, signatures=0 List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk > this point me and Jesper inclined to go with the second option. But maybe > I'm missing something, are there any other suggestions? Unfortunately I figured this would need a more invasive fix. I tend to agre= e that it'd be better to not skip in situations like this. I think it'd mak= e most sense to make any plan for these 'prepare/fetch' queries would not u= se skip, but rather a materialize node, right? -Floris=