X-Received: by 10.224.130.195 with SMTP id u3mr30599012qas.1.1367778136775; Sun, 05 May 2013 11:22:16 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.49.105.234 with SMTP id gp10mr1405153qeb.1.1367778136731; Sun, 05 May 2013 11:22:16 -0700 (PDT) Path: news.cambrium.nl!textnews.cambrium.nl!feeder3.cambriumusenet.nl!feed.tweaknews.nl!209.197.12.246.MISMATCH!nx02.iad01.newshosting.com!newshosting.com!news.glorb.com!m7no2460090qam.0!news-out.google.com!y6ni0qax.0!nntp.google.com!m7no2460086qam.0!postnews.google.com!z14g2000vba.googlegroups.com!not-for-mail Newsgroups: comp.databases.theory Date: Sun, 5 May 2013 11:22:16 -0700 (PDT) Complaints-To: groups-abuse@google.com Injection-Info: z14g2000vba.googlegroups.com; posting-host=41.142.77.176; posting-account=ICwiDwoAAADmc5U6HcJXmtqEzRkHXlWU NNTP-Posting-Host: 41.142.77.176 References: <515dc4c8$0$6066$e4fe514c@dreader36.news.xs4all.nl> <43eee84c-61eb-41cd-87bd-a7cf13a46c82@googlegroups.com> <6bbcbec3-adb2-4014-aa5a-f89f66d5c29b@googlegroups.com> <15eccbc4-b53a-4196-91b2-011ac4f91012@f18g2000vbs.googlegroups.com> <74b5393d-a532-4960-ab28-278772b8a013@googlegroups.com> User-Agent: G2/1.0 X-HTTP-UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_4) AppleWebKit/534.56.5 (KHTML, like Gecko) Version/5.1.6 Safari/534.56.5,gzip(gfe) Message-ID: <6234b504-f60a-4ee7-986e-c11f3c54da65@z14g2000vba.googlegroups.com> Subject: Re: The same simple question to relational theorist (with video now). From: Cimode Injection-Date: Sun, 05 May 2013 18:22:16 +0000 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Xref: news.cambrium.nl On 30 avr, 20:03, Erwin wrote: > Op zaterdag 20 april 2013 21:57:19 UTC+2 schreef Evgeniy Grigoriev het vo= lgende: > > > > > > > > > > > =D1=81=D1=83=D0=B1=D0=B1=D0=BE=D1=82=D0=B0, 20 =D0=B0=D0=BF=D1=80=D0=B5= =D0=BB=D1=8F 2013=C2=A0=D0=B3., 14:45:04 UTC+4 =D0=BF=D0=BE=D0=BB=D1=8C=D0= =B7=D0=BE=D0=B2=D0=B0=D1=82=D0=B5=D0=BB=D1=8C Eric =D0=BD=D0=B0=D0=BF=D0=B8= =D1=81=D0=B0=D0=BB: > > > Hi Eric. > > > Thank you! Also I don't want to think about how data is mapped (in both= direction!) between realtional representation and object-oriented descript= ion. > > > >I doubt it, because such mappings are an > > > > unresolved and probably unresolvable problem. > > > LOL. Eric, just look my video. I'm sure you will forsed to take these w= ords back. I claim I solve the problem. Look my video and try to object. > > Just watched some 25 mins of the video. > > A few wild thoughts, not claiming I understand much of it. > > The query results in your examples often show empty cells. =C2=A0If their= contents are something like NULL, then no, your system can almost by defin= ition not be relational. > > The system seems to be based on hierarchies of classes. =C2=A0That makes = me wonder about situations where there are self-references (boss of employe= e3 is employee2, boss of employee2 is employee7, ...) and transitive closur= es in the processing. > > I'm wondering how transactions/commit/rollback fit into the system. =C2= =A0If there is "autocommit" upon each NEW GOODS() executed, then I wonder a= bout the situations that require SQL users to switch over to deferred const= raint checking. =C2=A0(And if there is no possibility to declare constraint= s, then no, what you've created is not worth being called a DBMS. =C2=A0But= I rather doubt this is the case.) > > You also use the term "inheritance" in connection with your classes, but = it is unclear to me what "inheritance" really means here, or how it could b= e useful to me as a user of this system. Inheritance is a mean not an end. Defining the end by the mean is a OO mindset favorite lost cause.