RE: dual [was Re: Make MySQL syntax work in Informix]
The creation of a dual table is to "synch" with Oracle so that those who wish to migrate from Oracle will have an easier time doing so. Yes, Oracle's reason for creating a dual table is dumb. Informix's? Isn't. ;-) >From: "Southwell Schuyler" <southwel@mcao.maricopa.gov> >To: <informix-list@iiug.org> >Subject: RE: dual [was Re: Make MySQL syntax work in Informix] >Date: Fri, 6 Jul 2007 07:49:36 -0700 >MIME-Version: 1.0 >Received: from perform.iiug.org ([216.177.38.211]) by >bay0-mc1-f11.bay0.hotmail.com with Microsoft SMTPSVC(6.0.3790.2444); Fri, 6 >Jul 2007 07:50:04 -0700 >Received: from localhost (localhost [127.0.0.1])by perform.iiug.org >(Postfix) with ESMTP id 771249FF4;Fri, 6 Jul 2007 10:50:02 -0400 (EDT) >Received: from perform.iiug.org ([127.0.0.1])by localhost (perform.iiug.org >[127.0.0.1]) (amavisd-new, port 10024)with ESMTP id 29DmNH3HZE7F; Fri, 6 >Jul 2007 10:49:55 -0400 (EDT) >Received: by perform.iiug.org (Postfix, from userid 60001)id 29A47A02B; >Fri, 6 Jul 2007 10:49:55 -0400 (EDT) >Received: from perform.iiug.org (localhost [127.0.0.1])by perform.iiug.org >(Postfix) with ESMTP id 06DC79FF4;Fri, 6 Jul 2007 10:49:50 -0400 (EDT) >Received: from localhost (localhost [127.0.0.1])by perform.iiug.org >(Postfix) with ESMTP id A97789FE9for <informix-list@iiug.org>; Fri, 6 Jul >2007 10:49:46 -0400 (EDT) >Received: from perform.iiug.org ([127.0.0.1])by localhost (perform.iiug.org >[127.0.0.1]) (amavisd-new, port 10024)with ESMTP id nz7gvb2Kbj0Y for ><informix-list@iiug.org>;Fri, 6 Jul 2007 10:49:39 -0400 (EDT) >Received: by perform.iiug.org (Postfix, from userid 60001)id 69B289FF4; >Fri, 6 Jul 2007 10:49:39 -0400 (EDT) >Received: from mb2.maricopa.gov (mb2.maricopa.gov [156.42.10.187])by >perform.iiug.org (Postfix) with SMTP id 902719FE9for ><informix-list@iiug.org>; Fri, 6 Jul 2007 10:49:37 -0400 (EDT) >Received: from mcaoswss.mcao.maricopa.gov (mcao.maricopa.gov >[156.42.237.191])by mb2.maricopa.gov (8.13.1/9.99.9) with ESMTP id >l66EnbhQ004280for <informix-list@iiug.org>; Fri, 6 Jul 2007 07:49:37 -0700 >(MST) >Received: from mcaosx6.ca.mcao.maricopa.gov ([156.42.113.199]) by >mcaoswss.mcao.maricopa.gov with InterScan Message Security Suite;Fri, 06 >Jul 2007 07:49:36 -0700 >X-Message-Info: >LsUYwwHHNt1R4q9nOjVlzADhv1J3DH6w6od217Y7jErL4lkAygWZLZdglUhKvYpq >X-Virus-Scanned: amavisd-new at iiug.org >X-Original-To: informix-list@iiug.org >Delivered-To: informix-list@iiug.org >X-Virus-Scanned: amavisd-new at iiug.org >X-Greylist: domain auto-whitelisted by SQLgrey-1.7.5 >Content-class: urn:content-classes:message >X-MimeOLE: Produced By Microsoft Exchange V6.5 >X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: dual [was Re: Make >MySQL syntax work in Informix] >Thread-Index: Ace/YXALXUHASZIpQT6VDRO2DP0lHAAenb9A >X-imss-version: 2.047 >X-imss-result: Passed >X-imss-scanInfo: M:P L:E SM:0 >X-imss-tmaseResult: TT:0 TS:0.0000 TC:00 TRN:0 TV:3.6.1039(15282.000) >X-imss-scores: Clean:99.90000 C:2 M:3 S:5 R:5 >X-imss-settings: Baseline:4 C:4 M:4 S:3 R:3 (1.0000 1.0000) >X-BeenThere: informix-list@iiug.org >X-Mailman-Version: 2.1.6 >Precedence: list >List-Id: "comp.databases.informix" <informix-list.iiug.org> >List-Unsubscribe: ><http://www.iiug.org/mailman/listinfo/informix-list>,<mailto:informix-list-request@iiug.org?subject=unsubscribe>; >List-Archive: <http://www.iiug.org/pipermail/informix-list>; >List-Post: <mailto:informix-list@iiug.org> >List-Help: <mailto:informix-list-request@iiug.org?subject=help> >List-Subscribe: ><http://www.iiug.org/mailman/listinfo/informix-list>,<mailto:informix-list-request@iiug.org?subject=subscribe>; >Errors-To: informix-list-bounces@iiug.org >Return-Path: informix-list-bounces@iiug.org >X-OriginalArrivalTime: 06 Jul 2007 14:50:05.0155 (UTC) >FILETIME=[F0797330:01C7BFDC] > >Well, I thought that was strange, too. > >So, if inquiring minds want to know.... (From Wikipedia article on >"DUAL table") ... > >----- >History >The DUAL table was created by Chuck Weiss of Oracle corporation to >provide a table for joining in internal views: > > I created the DUAL table as an underlying object in the Oracle Data >Dictionary. It was never meant to be seen itself, but instead used >inside a view that was expected to be queried. The idea was that you >could do a JOIN to the DUAL table and create two rows in the result for >every one row in your table. Then, by using GROUP BY, the resulting join >could be summarized to show the amount of storage for the DATA extent >and for the INDEX extent(s). The name, DUAL, seemed apt for the process >of creating a pair of rows from just one. ( >http://web.archive.org/web/20041205061859/http://www.oracle.com/technolo >gy/oramag/oracle/02-jan/o12sendmail.html ) > >----- > >It appears to be used for more than the original intent... > >Schuyler L. Southwell >Software Engineer, Consulting >Maricopa County Attorney's Office >tel: 602 506 8107 >southwel@mcao.maricopa.gov > >-----Original Message----- >From: informix-list-bounces@iiug.org >[mailto:informix-list-bounces@iiug.org] On Behalf Of Richard Harnden >Sent: Thursday, July 05, 2007 5:04 PM >To: informix-list@iiug.org >Subject: dual [was Re: Make MySQL syntax work in Informix] > >Southwell Schuyler wrote: > > I see that Cheetah has implemented a "sysdual" table > >"dual" is such an idiotic name for a table with exactly one row, why on >Earth did Informix feel that they needed to copy Oracle's mistake? > >"dum" or "sysdum" I could've lived with. >_______________________________________________ >Informix-list mailing list >Informix-list@iiug.org >http://www.iiug.org/mailman/listinfo/informix-list ><< SouthwellSchuyler.vcf >> >_______________________________________________ >Informix-list mailing list >Informix-list@iiug.org >http://www.iiug.org/mailman/listinfo/informix-list _________________________________________________________________ http://imagine-windowslive.com/hotmail/?locale=en-us&ocid=TXT_TAGHM_migration_HM_mini_2G_0507