XPost: comp.lang.java.programmer   
   From: chris.uppal@metagnostic.REMOVE-THIS.org   
      
   fishfry wrote:   
      
   > > Yes, I would agree with the relational database. ORDB are mainly hype   
   > > and usually promoted by coders that have never had to write a report or   
   > > mine data effectively.   
   > >   
   >   
   > Is this really true? I'm an experienced database programmer learning the   
   > Java/OO way of doing things and I'm puzzled that people use Hibernate   
   > and similar tools to define objects, with the database serving as just a   
   > passive serialization mechanism with no thought to database theory.   
      
   It may help to consider the difference between:   
      
   a)    a program (or group of closely related programs) that   
         happens to require (ACID) persistence.   
      
   b)    a program that is required to manipulate independently-existing   
         data in a more-or-less public repository (database).   
      
   The difference is in whether the program or the data is primary.   
      
   The two are not the same, although the same technology /can/ be used to   
   approach both kinds of requirement.   
      
   In my opinion, O-R technologies are mostly about (a) -- that is to say they   
   provide a poor man's object database.  As such the issues you raise are largely   
   irrelevant.  (Of course, that's not to say that a /real/ object database should   
   only be viewed as a mere persistency mechanism, but the only one of those I   
   know of is GemStone.)   
      
   Many real life uses of databases, though, don't fall into the (a) category.   
   The data itself is /at least/ as important as the program(s) that manipulate   
   it.  Relational databases (and relational DB theory) are mostly about that   
   scenario.   
      
   I, personally, think there's a fairly severe conceptual mismatch between   
   table-centric relational databases and object-centric programming.  That   
   manifests in a number of ways, one of them is that it's awkward to do clean OO   
   programming against externally defined data (scenario b).  As a result,   
   programmers looking for a "quick fix" will naturally tend to try to use OR   
   technology to paper over the gap.  Whether that works well must depend on a   
   number of factors, and I can see why Tom might characterise it as "mostly hype"   
   (I don't have enough experience of OR to agree or disagree), but I think that   
   what's really happening is that a tool designed for one purpose ("poor man's   
   object database") is being used for another purpose.  When you get right down   
   to it, that is little more than a hack.  Like all hacks, it /might/ work well,   
   even very well, for some purpose, but it's not the same thing as using the   
   right tool for the job.   
      
       -- chris   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)