Ted, what you're saying is what I meant really. Yes, it's not an easy problem to solve. In most cases you just change the schema in a maintenance phase.
Cheers, Ara. > -----Original Message----- > From: Ted Neward [mailto:[EMAIL PROTECTED]] > Sent: Tuesday, April 16, 2002 11:20 PM > To: Ara Abrahamian; [EMAIL PROTECTED] > Subject: Re: Re: [EJB-INT] 3rd normal form & EJB > > You have GOT to be kidding me--bringing down a database should be the last > possible thing you consider, particularly if this database has any kind of > a > user population greater than 1. > > The problem with the "reserved columns" approach is multifold: > 1) Column names aren't indicative of data stored. > 2) No relational integrity can be applied to the columnar data, since we > don't know what the relationships are yet. > 3) Columnar data must be stored in some "transparent" fashion, usually > either a string or a blob, which leads to having to translate the data to > and from the database (if it's an int value, for example). > > Most of the major databases will allow you to *add* to the schema without > having to drop the database, but in general, whenever you're looking at a > schema change, you're looking at a major happening. Some Object-Relational > mapping layers have taken to storing the objects directly into the > database > as binary columns, but this is another last-resort idea, since it means > that > you lose the ability to do SQL queries on object attributes (which is part > of the whole reason you store data in an RDBMS in the first place, right? > :) ). > > In short, this is *not* an easy problem to solve. Your DBA should be > praised > for raising it. Now the question to your EJB vendor becomes how do *they* > want to deal with it? Some, if they created the schema in the first place, > will do some pretty drastic things that will anger and annoy your DBA if > you're not careful. > > Ted Neward > {.NET || Java} Course Author & Instructor, DevelopMentor > (http://www.develop.com) > http://www.javageeks.com/tneward > http://www.clrgeeks.com/tneward > > ----- Original Message ----- > From: "Ara Abrahamian" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Tuesday, April 16, 2002 10:10 AM > Subject: Re: [EJB-INT] 3rd normal form & EJB > > > > If you really care about it you can add some dummy/reserved columns of > > common types. Don't use them now, but when you need a new attribute just > > use one of those reserved columns!! I've seen this trick in an RPG app > > ;-) But who cares about this issue? Just bring down the server for > > maintenance and update the database. > > > > Ara. > > > > > -----Original Message----- > > > From: A mailing list for Enterprise JavaBeans development [mailto:EJB- > > > [EMAIL PROTECTED]] On Behalf Of Mindaugas Kairys > > > Sent: Tuesday, April 16, 2002 1:29 PM > > > To: [EMAIL PROTECTED] > > > Subject: 3rd normal form & EJB > > > > > > Hello, > > > I have such philosophical, but real problem. My Oracle admin asks me, > > why > > > are you using such plane database design, what will you do, when it > > will > > > come the need for new object attributes: alter tables, change program > > > code, > > > stop server....? > > > > > > I'd wanted to hear opinions, suggestions, the ways you solve that > > problem > > > from you and ask what tools, tips, patterns one should use to archieve > > > database design of 3rd normal form normalization level using EJB? I > > know > > > that CMP entity EJB will be solution to achieve that, but it takes too > > > much > > > time. Mhm... > > > > > > Mindaugas Kairys > > > > > > > > ======================================================================== > > == > > > = > > > To unsubscribe, send email to [EMAIL PROTECTED] and include in the > > > body > > > of the message "signoff EJB-INTEREST". For general help, send email > > to > > > [EMAIL PROTECTED] and include in the body of the message "help". > > > > > > _________________________________________________________ > > Do You Yahoo!? > > Get your free @yahoo.com address at http://mail.yahoo.com > > > > > > > ======================================================================== == > = > > To unsubscribe, send email to [EMAIL PROTECTED] and include in the > body > > of the message "signoff EJB-INTEREST". For general help, send email to > > [EMAIL PROTECTED] and include in the body of the message "help". > > _________________________________________________________ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.com =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff EJB-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
