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 1gPAXF-0005bL-IF for pgsql-docs@arkaria.postgresql.org; Tue, 20 Nov 2018 18:14:05 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.89) (envelope-from ) id 1gPAXE-0006as-0F for pgsql-docs@arkaria.postgresql.org; Tue, 20 Nov 2018 18:14:04 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1gPAXD-0006ab-Nk for pgsql-docs@lists.postgresql.org; Tue, 20 Nov 2018 18:14:03 +0000 Received: from meldrar.postgresql.org ([2a02:c0:301:0:ffff::31]) by makus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1gPAXB-0001n5-25 for pgsql-docs@lists.postgresql.org; Tue, 20 Nov 2018 18:14:02 +0000 Received: from rrcs-72-43-120-210.nyc.biz.rr.com ([72.43.120.210] helo=Ph33r-Retina.local) by meldrar.postgresql.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1gPAX7-00063I-8y; Tue, 20 Nov 2018 18:13:59 +0000 Subject: Re: Documentation for create unique index is insuficient and (because of that) incorrect To: Alvaro Herrera , Tom Lane Cc: Bruce Momjian , emilioplatzer@gmail.com, pgsql-docs@lists.postgresql.org References: <20181120180831.frne3ck56mfdh573@alvherre.pgsql> From: "Jonathan S. Katz" Openpgp: preference=signencrypt Autocrypt: addr=jkatz@postgresql.org; keydata= xsFNBFtShwABEAC7PNHDUOTYuifpUCk23KqfxdQQkn4nkoxOXRK0+rAj36FiwqGB4TJFuOVZ sDFAEiSlC8Jt4y5Cs7B5tetT8JNd2cs6zp/udMJJDz9d65O9PDpdlMgAmIiTzpLlSdx8FG56 DTksaDv1d8j3cTJPSE4/fWSxqzA7o3Y9UuL7atZPrzfImgpRKs0of7elIHwOa8GucjyhYqcR h60wFBJc2KXqQdDYRTZy43DSnY/0VNc0omiH355fustvpm+m5HjD3w7qZyfN3fpKJpnX1LCF f3MnPHaDGITIYGRCBXvf0UqUtD6OEVWPv2C2gyqWMIpWmZTOgDufltKyIByKBoS9x0PlFkij 04X3KODCngt+N8Ssc9OICc6QSxhjoP48PYPdmiTmkrGuf0LX084wj1xeo1NX7XxZK39F6dTJ DhsIiW0sNS0xMxQHLHG9VLbPjx3SANQBh6BuryPz5ZupW9/TIDmkvprtU/oXfKgtfYm3fxmk EctxbWrEPsFTFPyuMqQu6l+xyQv0s1VLZfjNWaua6H1/gGoIt6kRnn5qMXDVVpijuWkHbv7G ngaQMd258UrrOEHnnjzhQ7jxMWV9D+emxbAtlIxnYvCWlV4IwAQhEHfvudqYaIY3hNWrvQ6H GB2KXoTZYN9g5djm14/5nj1IU5zOcovkjJnKhoo9iStnpFF2cwARAQABzTFKb25hdGhhbiBT LiBLYXR6IDxqb25hdGhhbi5rYXR6QGV4Y292ZW50dXJlcy5jb20+wsGXBBMBCABBAhsDBQkH hh+ABQsJCAcCBhUKCQgLAgQWAgMBAh4BAheAFiEE+oS2la8r95ogZD/x8QSccp8cZScFAltS iSUCGQEACgkQ8QSccp8cZSfqrQ//bcMXxIqELT+DMa2C5IR4K3kRsdgxC2mcdsO4XgRxNLQF uZYqKa85EEZ+O4O/oHV5AgckWRcxCUNI0qafwC+QNTc/lBecmMipbP1X2+A8RBiTBRpSgo9y BOQ2xmA70k32Rk4hLd9EVTb0eXe9DoJIXWOsMlqqpqEuXiaoH5a2Ww6DdpCMN1vQZ/HavbAG cXV3MXahiqmBhH6Y0v1kZTJYEOCw0w4U1Q/vdUKw9/jv+fidU6I/jafHAxda7pI+dtNOyUtC bmv+9+KreUeBqyBXGmNFDZ4wa4TvYfaw6VV3acNT5KgcefQpd7JlzM+Vq3zz1tnR4C50nEpg DEpf0ANyeZ48v5+M7ycoIbxAHzwzKsiTaVmMDYRdnxmlv18UaWc/wmoI0wFAtcGjfw5KJLQv oolZYP18S0mpH2Q8SxcXbqekDvsHVW04Jkult9xZSeijdzUzcumflCZ2Y5VQKNjG99eZh5Iq JcUdYJH5mdmdFWgZdYTT6tZWHCMBBDBqktzLmyBezrqT0+j3E5lL/30tkatrcDkNPd3lE/j1 OxG10xVvCqzBvksBR0VX/RLKmj2wvIMqKoCav1GgBIdVAuLSO4CyWkWRRawpcREwUvNKyL2E uPXqsqTzYrYRxUM7GmjY3x40/IiA0uJCuxYEIeelmOwFEnadvyFUJxseVsczl/DOwU0EW1KH AAEQAL/IaP7aEPQxt4+H/YfZ9WkR69hZb4jdlLacui/PnXw4IDtIHopZpBkDqJWdhOtIBn8n v5FLRfVtzQcjuIcQ0fbuqmzl3Hap7gPnHOvBH6pVhSa1bWBcbdIeBJVmDmJyHsyrYa4lnIfx WO9BRq8bN8/FBzh6udMAVuN93k72ZvdFosQYlxLdr9Q4FuFa98pnzuwGqfyGMj7hOCc4LnQL gJdByj8jRB1hxtXQG419UYgsPYJJyA1kDhdAeFAGiXLVhlXJ2dwNlC8DRjGtT/WSZQVn9b3I 9NWohzFNMkOyYyYkqb35vXjNLki8EXQ6yY8peWWalbpo3b9kjDUPBr2EWxDMrNxhg0rfc14H wklJz5yX2MY8wR0SOseOFn7MfEuoVsXqTqIAiSf4OuwZPZmPGFeJJViFwyVTi+Y5wQtPQ27G RvNSWhNkMQfGO1t+mTK6IvVzMYN7PNOYUAEFL3Rv6aFPITfAVna505v/uHkEKe4A2NXjw5hj OmyQvjhzkpxbUf3/u9M6SiddHHO3AcoBp5dckdyo4RcgFlBbz+GRs4ignKTMF2X3vTxrsgP2 DrmzKYcSJ92LCtsK3X2imWF9hjGQmYTDHL8fSKUK8SCYFPlZcF7vzvi5NdFSD3MTyScJqXSO h83EvGYBuiDHAuOOF107i2j/I9poHDL2GpN0nAspABEBAAHCwXwEGAEIACYWIQT6hLaVryv3 miBkP/HxBJxynxxlJwUCW1KHAAIbDAUJB4YfgAAKCRDxBJxynxxlJ0XjD/0QNlIRkI/huLgb IZES46UcrGm3T6oEAXRAZOsGG4qPPFoP9v4YGO1M5gwxMF97GX0A3KyOvryKGyPLqrLWSA/l oAAGtSS3woTMlUJ0stM31jDgAV7HHObRrrxUWbyZJU4rLDBY11MGkRBCqeGYpE7yf+tjAo0n ba1IZzy76E7B0ykSg4nIRPm+QOeGpcLLm04o8Ndjujdtq+SI2YokmVdLu3bEocisPu8Akmsf X7gaBONzTGH/nZ4zCp3qwEGFHGVmDJ5PhAvEWqmAMb+l2drSsdQJBhpLcJECAcK8/SJQ0ryd y1idlCCLi0U3Z4DYIBiC+M87lGtheeharJECLmDGjRE5Oi2H2pQQ0Ok1SwHIAj0MaeJOIvz0 bGd5WdmYUR0WHIjr5pKfiOhHx8JZUKWK1rNbYZbgRqpSUlSYCpdCDhbyi7EOiin6swMIehca zuamo6eL4jSILVqBcDuQadI4BU2x9jqzFiEX1HVAh9Q427qOubL4TY+xTbEFWMxwyPjXdSPy zgaD3N1KK0TBdjOCVZFEe7JDh1lGz00jVK+6nNeDUjGNzyoxnlRgLAVRwT75kcf0rNrVv06S VqcYOKZqrhUEl7mmIWH+BTfEsct9tKXK/hajfAIWZGCXDWPNjk7UeVRCkQv5mHMqutalyCqp 4MnZ+/WyYxsR4qcchRZhAg== Message-ID: <000aef3d-4183-d345-5d18-b811c4838160@postgresql.org> Date: Tue, 20 Nov 2018 13:13:51 -0500 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:60.0) Gecko/20100101 Thunderbird/60.3.1 MIME-Version: 1.0 In-Reply-To: <20181120180831.frne3ck56mfdh573@alvherre.pgsql> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="FyJYqIJxI54hsiaOYYvCaNRpsmZhZQqVe" List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --FyJYqIJxI54hsiaOYYvCaNRpsmZhZQqVe Content-Type: multipart/mixed; boundary="YaM2N2CaBcOIaLImvmplWn9YXUAjwnh0o"; protected-headers="v1" From: "Jonathan S. Katz" To: Alvaro Herrera , Tom Lane Cc: Bruce Momjian , emilioplatzer@gmail.com, pgsql-docs@lists.postgresql.org Message-ID: <000aef3d-4183-d345-5d18-b811c4838160@postgresql.org> Subject: Re: Documentation for create unique index is insuficient and (because of that) incorrect References: <20181120180831.frne3ck56mfdh573@alvherre.pgsql> In-Reply-To: <20181120180831.frne3ck56mfdh573@alvherre.pgsql> --YaM2N2CaBcOIaLImvmplWn9YXUAjwnh0o Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 11/20/18 1:08 PM, Alvaro Herrera wrote: > On 2018-Nov-20, Tom Lane wrote: >=20 >> So what I think I should do is reformulate that discussion to talk >> about making covering indexes with INCLUDE, and then mention in >> passing that you can also do it without that as long as you don't mind= >> the payload columns being part of the index semantics. >=20 > That seems sensible. +1 >=20 >> I'm also wondering whether to move that section someplace earlier >> in chapter 11. Right now it's near the end because it's mostly >> info about an implementation detail; but it wouldn't be hard to >> make the argument that covering indexes are more important than, >> say, indexes with custom collations. Should we move it, and if >> so to where? >=20 > I think right next to 11.5, which currently completes the topic of how > are indexes used, is a good place. I would vote at least before 11.9. You could make arguments how understand how multicolumn, expression indexes, partials, etc. could be more important, or at least used for frequently in the wild (at least for now). And once we've explained those types then you could understand how to use covering indexes appropriately. Jonathan --YaM2N2CaBcOIaLImvmplWn9YXUAjwnh0o-- --FyJYqIJxI54hsiaOYYvCaNRpsmZhZQqVe Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEE+oS2la8r95ogZD/x8QSccp8cZScFAlv0TuAACgkQ8QSccp8c ZSc+1Q/7BKmHapG9Pw7OcaWkNqlLWvGU9qCZhadoWKFM4nOInlVJ+AWGAUGrzmZd QA0PRWEX98APCr2KMozXcHt+hbmBmxKgBRsUyc+FRB9mDoIkG004ouSF6TzBDc2y TvrR0+G3KpkOx+PhjASUWBN8fKJWwPBwgOeu1yid9sL15K4zHmK/3Hje3DovudhZ uYbHT720+xDWte8etNgrwMkg/M8hZOdVGQQ93QJ/WKDas0icfcy0EmjTgbHTtBFX wayCJTqoJSOfWTNtKt7faVqki7MaUvnTHAoltPRJL0Dmy3Yz/cvfOOfwCCJ6QOgx xsmeHAHz/muv598HvRx4MHxDA/lJN/guE5qZkWRve3zP59fiArZNkT3evJh2y4/T Hib6ly0LAXOYbv7sUVFhQ+tLQDcI7Pp+mz5aGiBUOT3JsDrf3DzVzATvPc61u3bp ScsWfySm7c3DTuGhrQtsm+W8oLKcHM5fFcxp9wpyKVZ2ZPS34Y2lyL1se6vjVQJq z1LUrzJzUeLrfuME4THYzA/r82xUVdXTz/CUPBbfLAYCHoBWN3dh8RnMhQ3wqGdH sdPOMYVsnBWIjMYnewIyaFkR8jAAHNiIci6ySOCCqaq3J6V04d+qbCr8Kp1iHDul cTPxbnw3AEXmk7Oz7R5KN0iPjGkzFrePseAzZm+eF4m4KIlDJTA= =oCuq -----END PGP SIGNATURE----- --FyJYqIJxI54hsiaOYYvCaNRpsmZhZQqVe--