ORM2

installing NORMA

akl — 2006-07-27T12:27:38Z

I have not gotten a reply as either. That’s why I posted here. I will continue to look for login to Sourceforge but for now I put VEA on my new laptop so I can continue with ORM. Thanks for the reply.

Allan Lindgren

"If I were a king" wish: to clearly separate conceptual modeling

Frankus — 2006-05-28T19:19:54Z

well, conceptual modeling isn´t something new introduced with orm and therefore the terms you mentioned are precisely defined by other authors. But as with the term "scheme" you seem to be right; it is used in another sense than usual (imho it means the usage of a data model on a concrete UoD).

proposal: to unambiguate ORM terms from the p.v. of O., R. and M.

g_vanine — 2005-06-25T13:04:22Z

I reprint here some ORM definitions:

Relation - a named table with a set of named columns and populated by a set of unnamed rows

Role - a part played ny an object type (again by a population, i.e. many objects?!) within a prediicate

Uniqueness - (sorry I just Copy&Pasted this "definition") - prevents duplication of role instances

These are really definitions how they are used (and not just proclaimed) in ORM. Meanwhile there are quite a bunch of other "definitions" with the use of underdefined, ambiguous and contradictory to each other terms and implications.

I understand that this is very comfortable to have a named table with unnamed rows for persistence and storage,

but if ORM is about Object , Role and Modeling than the notions/terms should not be about tables, rows and populations but about roles (and relations) played by each instance of an entity type:
for ex., Each Person(or ssn number) was born in how many Countries (i.e. CountryCodes)? In each Country (i.e. CountryCode) how many different Persons(i.e. ssn numbers) were born?

Really, such understandig and even such types of questions appear in ORM (and VEA, VisioModeler, InfoModeler), though without any real utilization and being immediately completely inverted into the terms of RDBMS persistence, i.e. instance populations like column table uniqueness but not object (of the same instance) role uniqueness
While the RDBMS conveniences shouldn't even appear at conceptual level modeling.

This is very nice to have uniquenes in column of persisted table. But in modeling I am interested, first of all, in uniqueness of roles (role instances) PER (one, each of the) instance/object. The same role instance among population (many different instances of object entity) is very helpful for storage but not for modeling.

Meanwhile there is a big confusion and even absence of unique unambiguous definitions of terms in ORM. This is also in odds with UML while it is written that ORM notation and terms are equivalent (ueaah, they are just proclaimed so).

Then appear obvious problems in tools mapping, interoperability which are attributed to tools implementation bugs and underdevelopment while they are theoretical ambiguities impossibilitating any simple and obvious practitioning .

But where is ado about ORM2?

g_vanine — 2005-06-19T09:13:11Z

Here is openable BSBR link
http://www.pdata.com/jMM/BSBR.htm
Though I could not clearly get (yet? or eventually?) how to navigate there

Welcome

Scot — 2005-03-22T13:09:26Z

Welcome to the ObjectRoleModeling.com ORM2 Discussion forum. Any (logged in) member of the site is welcome to post here. If your topic is related to a non-ORM2 topic for which there is a specific forum (e.g. ORM, Visio, Orthogonal Toolbox, General Discussion), please post in that forum instead.