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dual [was Re: Make MySQL syntax work in Informix]

Posted in 2007

Topics: General Discussion

Richard Harnden — — source: Usenet: comp.databases.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.

↪ replying to Richard Harnden
Southwell Schuyler — — source: Usenet: comp.databases.informix

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

↪ replying to Richard Harnden
Jonathan Leffler — — source: Usenet: comp.databases.informix

On Jul 5, 5:03 pm, Richard Harnden <rich...@oninit.com> wrote: > 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. Surely, you had in mind dee or sysdee :) In Darwen and Date's work, DEE is the table with no columns and a single row, DUM is the empty table with no column. (I use 'DUM is dumb' - unable to speak - to memorize which is which.)

↪ replying to Jonathan Leffler
Richard Harnden — — source: Usenet: comp.databases.informix

Jonathan Leffler wrote: > On Jul 5, 5:03 pm, Richard Harnden <rich...@oninit.com> wrote: >> 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. > > Surely, you had in mind dee or sysdee :) Yep :) I always manage get them the wrong way round. > > In Darwen and Date's work, DEE is the table with no columns and a > single row, DUM is the empty table with no column. (I use 'DUM is > dumb' - unable to speak - to memorize which is which.) >