RE: RE: (ROSE) ROSE: Generating a DDL script

[Walter Howard]

No argument from me.  The companies that care about data and recognize that it is an asset all have data analysts on staff that are an integral part of the requirements gathering process.  What I'm confused about is the previously suggested approach.  It's not feasible for a logical data model and the application class model to share the same class model.  The application class model has all sorts of artifacts that obfuscate the underlying data relationships.  Additionally, different rules apply to building class models than to data models.  How can someone share a design where the analysis techniques differ? Regards, Walter >>> "Maksimchuk, Robert" <[EMAIL PROTECTED]> 03/23/01 12:25PM >>> You are right Walter, a class model will not transform into a good data model automatically.  It still does require the skills of the database designer to turn it into a logical data model into "functional database".  No doubt about that.  And yes it will and should look very different.  I also agree that the physical stuff (precision, scale) should be specified in the physical model (sorry if I wasn't clear on that). However, having the database and application people work separately, with separate models is the way things have been done for a long time.  Now with the availability of the UML for database design and application design there are many advantages of having both teams working from the same design.  This is especially true if, as some of our customers are doing, the database people become involved early in the lifecycle, say at the Business Modeling level.  After all, they know the existing database entities.  Who better to "guard" those all important domain level concepts? Either approach can work, we are just striving to leverage improved communication between the app and DB teams. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Robert A. Maksimchuk Data Modeling Evangelist R a t i o n a l     the e-development company Phone: (610)-940-2124 [EMAIL PROTECTED] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~   -----Original Message----- From: Walter Howard [mailto:[EMAIL PROTECTED]] Sent: Friday, March 23, 2001 11:37 AM To: [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: RE: RE: (ROSE) ROSE: Generating a DDL script Interesting approach.  I don't think it will work though.  The problem is that a logical data model looks different that a class model of an application.  In fact it can look significantly different.  Just specifying attributes within a class model as persistent won't get you a good logical data model much less a functional database.  I always looked at the data modeler building his own class model in conjunction with the application folks building their class model.  This model is separate from the application class model.  IMO, this is the only way to accurately capture the data requirements without the excess application baggage.  Precision and scale should be specified at the physical model level.  Only the domain should be specified at the logical level.  The logical model is technology independent.  If you include physical characteristics of a target DBMS in your logical model, you lose the portability of the design. Regards, Walter >>> "Maksimchuk, Robert" <[EMAIL PROTECTED]> 03/23/01 07:59AM >>> 1. Precision and scale can be changed in the Table Specification.  Select the column and double click to open the Column Spec.  Go to the Type tab. 2. We recommend that the class diagram (logical model) be used as the common "blueprint" for both the application and database folks.  App developers use this diagram as they always have to build the apps and database folks transform the persistent classes into a data model to do the database design.  So when do you make the split?  There is not a black and white answer.  The earliest you should to this would be when all the attributes are fully elaborated in the class diagram.  The latest would be when all the operations are fully elaborated.  The challenge you run into is, the earlier you do the transform the more likely the database design will be impacted by changes.  And of course the later you transform, you may be less impacted by changes to the logical model, but your project schedule may not be able to stand the strain.  This is all heavily influenced by your schedule and your company's culture. 3.  Depends on the details of your specific situation. 4.  The help files contain the information you need. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Robert A. Maksimchuk Data Modeling Evangelist R a t i o n a l     the e-development company Phone: (610)-940-2124 [EMAIL PROTECTED] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: Thursday, March 22, 2001 2:57 PM To: [EMAIL PROTECTED]; [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Subject: Re: RE: (ROSE) ROSE: Generating a DDL script Todd and Davor, Thanks for the response. My question(s) now : 1. Where  does one specify the attribute data type & prescision targeted to the Oracle database(e.g. Number(15,2), Varchar2(50) etc)- in the class diagram or the data model diagram? 2. Are there any guidelines describing how much information should be entered in the class diagram as opposed to the data model diagram? 3.Is it recommended to import Oracle8 scalar data types and use them in the class diagram itself? 4. I tried to define a global domain package containing oracle domains to use in the class diagram but could not find any documentation on how exactly to do them Thanks, Abby ========================================== "Gornik, Davor" <[EMAIL PROTECTED]> wrote: > > Abby, > > We replaced the direct way with the design driven way of generating the > database with the data modelier add-in, which gives you all of the power to > optimize the physical design of the database and model constraints, > triggers, etc. If you need a good database design, data modeler is the tool > to go for. > This means you can not generate the table directly from a class, because > some physical information is missing. > However some scripts might exist for the class based ddl genreration. > > Cheers! > > Davor Gornik > Marketing Engineer Rose Business Unit > Rational Software > Phone: +1-425-497-4091 > Email: [EMAIL PROTECTED] > -------------------------------------------------------------------- > > Rational User Conference 2001 > July 22 - 26,  2001 * Denver, CO, USA > http://www.rational.com/ruc > > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] > Sent: Thursday, March 22, 2001 5:53 AM > To: [EMAIL PROTECTED] > Subject: (ROSE) ROSE: Generating a DDL script > > > > Is there a way to directly generate a ddl from a class diagram(all classes > tagged persistent)rather than going through the data modeler add-in and > first creating a schema. > I shall appreciate any feeback on this. > > Thanks, > Abby > > > __________________________________________________________________ > Get your own FREE, personal Netscape Webmail account today at > http://webmail.netscape.com/ > ************************************************************************ > * Rose Forum is a public venue for ideas and discussions. > * For technical support, visit http://www.rational.com/support > * > * Admin.Subscription Requests: [EMAIL PROTECTED] > * Archive of messages: > http://www.rational.com/products/rose/usergroups/rose_forum.jtmpl > * Other Requests: [EMAIL PROTECTED] > * > * To unsubscribe from the list, please send email > * > * To: [EMAIL PROTECTED] > * Subject:<BLANK> > * Body: unsubscribe rose_forum > * > ************************************************************************* > __________________________________________________________________ Get your own FREE, personal Netscape Webmail account today at http://webmail.netscape.com/ ************************************************************************ * Rose Forum is a public venue for ideas and discussions. * For technical support, visit http://www.rational.com/support * * Admin.Subscription Requests: [EMAIL PROTECTED] * Archive of messages: http://www.rational.com/products/rose/usergroups/rose_forum.jtmpl * Other Requests: [EMAIL PROTECTED] * * To unsubscribe from the list, please send email * * To: [EMAIL PROTECTED] * Subject:<BLANK> * Body: unsubscribe rose_forum * ************************************************************************* ************************************************************************ * Rose Forum is a public venue for ideas and discussions. * For technical support, visit http://www.rational.com/support * * Admin.Subscription Requests: [EMAIL PROTECTED] * Archive of messages: http://www.rational.com/products/rose/usergroups/rose_forum.jtmpl * Other Requests: [EMAIL PROTECTED] * * To unsubscribe from the list, please send email * * To: [EMAIL PROTECTED] * Subject:<BLANK> * Body: unsubscribe rose_forum * *************************************************************************