Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1YQwtH-0000oV-5D for pgsql-performance@arkaria.postgresql.org; Thu, 26 Feb 2015 11:46:03 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.80) (envelope-from ) id 1YQwtG-0006cs-0r for pgsql-performance@arkaria.postgresql.org; Thu, 26 Feb 2015 11:46:02 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1YQwtF-0006cS-7B for pgsql-performance@postgresql.org; Thu, 26 Feb 2015 11:46:01 +0000 Received: from plane.gmane.org ([80.91.229.3]) by magus.postgresql.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:256) (Exim 4.80) (envelope-from ) id 1YQwtB-0000hP-Pe for pgsql-performance@postgresql.org; Thu, 26 Feb 2015 11:46:00 +0000 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1YQwt7-00047j-U7 for pgsql-performance@postgresql.org; Thu, 26 Feb 2015 12:45:54 +0100 Received: from 185.40.248.10 ([185.40.248.10]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 26 Feb 2015 12:45:53 +0100 Received: from spam_eater by 185.40.248.10 with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 26 Feb 2015 12:45:53 +0100 X-Injected-Via-Gmane: http://gmane.org/ To: pgsql-performance@postgresql.org From: Thomas Kellerer Subject: Re: Reverse Key Index Date: Thu, 26 Feb 2015 12:45:46 +0100 Lines: 15 Message-ID: References: <54DF9036.8080502@tbz-pariv.de> <7978.1423937899@sss.pgh.pa.us> <54DF9559.8080109@tbz-pariv.de> <54EE4D45.1060704@agliodbs.com> <54EEFDA1.7020609@tbz-pariv.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: 185.40.248.10 User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.23) Gecko/20090812 Thunderbird/2.0.0.23 Mnenhy/0.7.6.666 In-Reply-To: <54EEFDA1.7020609@tbz-pariv.de> X-Pg-Spam-Score: 0.8 (/) List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-performance Precedence: bulk Sender: pgsql-performance-owner@postgresql.org Sven R. Kunze schrieb am 26.02.2015 um 12:04: > I just thought about btree indexes here mainly because they well-known and well-used in ORM frameworks. If your ORM framework needs to know about the internals of an index definition or even requires a certain index type, then you should ditch that ORM framework. Apart from indexes supporting business constraints (e.g. a unique index) neither the application nor the the ORM framework should care about indexes at all. > does PostgreSQL support the concept of reverse key indexing as described here? The real question is: why do you think you need such an index? Do you have any performance problems with the existing BTree index? If yes, which problem exactly? Thomas -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance