Re: object oriented vs object relational

From: David McCarthy <>
Date: Wed, 29 May 2002 16:23:20 GMT
Message-ID: <Yf7J8.12267$>

Akmal & Carl,

Thanks a lot for your answers, they were very informative. Akmal, I pulled down one of the briefings & I found it to be very helpful.

Thanks again.

"Carl Rosenberger" <> wrote in message news:ad2m2n$9m8$07$
> David McCarthy wrote:
> > Would someone please explain to me the difference between a
> > object-oriented data base model and an object relational database model?
> David,
> there is a wide range of products that call themselves
> "object databases" or "object-relational databases"
> and in some cases the marketing term has very little to
> do with the technology.
> Looking at the "typical" representatives, I would describe
> the principal differences as follows:
> Object-Relational
> -----------------
> - tables
> - powerful query language, typically SQL with possible
> extensions for "object" capabilites
> - no automatic association between objects in the programming
> language and "objects" in the database. You have to write
> your own insert and update code.
> Object Databases
> ----------------
> - no tables, objects are stored directly
> - weak querying functionality
> - very tight association between objects in the programming
> language and objects in the database. Most systems monitor
> the objects that are loaded from the persistent storage to
> be able to perform updates automatically.
> To sum it up as simple as possible:
> Object databases provide you with far better capabilities
> to store objects and to navigate through them. They will
> save you a lot of implementation work and they will provide
> excellent performance for this task.
> Object-Relational databases will provide you with better
> querying functionality.
> There are quite a few object databases that are currently
> improving their querying functionality and I could imagine
> that we will see a wide support of SQL at some time in the
> future.
> > I would also appreciate it, if you could point me to a reference,
> > preferably on the web, that I could use to research the advantages,
> > disadvantages , features, strength and market share of each.
> Akmal has posted references to some very old papers but
> the theory has not changed dramatically in the past years.
> I do not share Akmal's impression at all that object databases
> are going down. I have not seen too many productive statements
> from Akmal throughout the last year other than references to
> links in the web and to his dusty books and papers so I doubt
> that he really is in contact with practitioners. I see lots and
> lots of demand for systems that map objects to tables. If the
> interfaces to do so are further standardized (as JDO tries to,
> not too good and not too successful, I am afraid) it will not
> make a difference, whether a relational database runs behind
> the interface or an object database. Object databases will
> provide the better performance for the task, since the path
> from object to disk is more direct, so they will continue to
> catch market share for new systems.
> ...especially in the mobile and embedded market, where
> low ressource-consumption is essential.
> Kind regards,
> Carl
> ---
> Carl Rosenberger
> db4o - database for objects -
Received on Wed May 29 2002 - 18:23:20 CEST

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