Re: Object support in the relational model??

Costin Cozianu wrote:
> Why don't you put the documentation of your product online, so we
> could form an independent opinion, instead of taking your half-baked
> advertising ?

With the risc of being called for trolling, because I respond to your request, the documentation is online: http://www.db4o.com/db4o/doc/index.html

> Yes, it does seem like a serious contender aginst ObjectOutputStream.
> Not against Oracle though. You fail to see the difference.

Oracle will not run on a handheld and it is not a good idea to download an Oracle database engine with a Java Webstart application. The JDBC driver on it's own has a size of 1.5 MB. I do see the difference.

> > I could bore you with other dozens of features but I would rather continue
> > to call our product a database engine.
>
> Please do bore me on how you provide queries. Is QBE what you call
> decent query capability ?

The following API will be released shortly: http://www.odbms.org/soda/

If you remember, I had a long flamewar here with Bob Badour a year ago, when I asked (friendly) for productive comments, without advertising anything. This was one of the "real" discussions without a commercial background, that Leandro was asking for, but all I received here was flames.

In the meanwhile there are some other products that have considered to adopt the API. I even received some mails from interested Oracle people.

OJB, an open source object-relational mapper, and just about to become an Apache project, already provides parts of S.O.D.A. with the download: http://objectbridge.sourceforge.net/

> Do bore me on exactly how you do provide concurrency control through
> logical isolation levels, backup and recovery and other DBMS features.

We provide one isolation level only:
read committed

Currently there is no online-backup system implemented. The engine shuts down and starts up in a second so you may simply backup the database file. You also have the possibility to open multiple concurrent database files and move objects (and all attached objects of course) freely between them.

Concerning crash recovery:
If the JVM/OS/hardware/whatever crashes during transaction commit, the commit will be restarted and finished with the next start of the engine.

> Last time I read your postings some time ago, you referred to a db4o
> VS SQL bechmark that was so badly written (the Java/Jdbc part), that I
> could hardly have presumed you as knowledgeable about databases.

I agree that the code is very ugly, since it was not written with love for SQL, but it tests, what it is supposed to. If you remember, someone else reading along here tried to optimise the code for speed, with little success.

> Your
> public attitude of misrepresenting your product and the ignorance
> exposed in your early postings were enough for me to form a judgement
> (and for some others apparently).

I can see that and since there has not been a single friendly response in this thread, I guess there may be more people annoyed. Should there be further questions concerning db4o, please ask by private mail.

> Maybe in the meantime your product has grown and you read more books.

Maybe. The benchmark code is still awfully ugly.

> You just don't get the presumption of innocence anymore :)

Did I ever get the presumption?
I didn't notice.

Cheers,
Carl Received on Wed Jun 12 2002 - 21:32:56 CEST