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Re: 1GB Tables as Classes, or Tables as Types, and all that refuted

From: Dawn M. Wolthuis <dwolt_at_tincat-group.comREMOVE>
Date: Thu, 9 Dec 2004 20:42:18 -0600
Message-ID: <cpb2es$t9m$>

"Alfredo Novoa" <> wrote in message
> On Tue, 7 Dec 2004 18:33:27 -0600, "Dawn M. Wolthuis"
> <dwolt_at_tincat-group.comREMOVE> wrote:
>>So, the 1GB has nothing at all to do with using a class to define a
>>type, such as "Person" -- is that correct?

I can use an OO language to define a

public class Relation

just as easily as any other type, right?

> It is not possible to use a class to define a relation type, but the
> 1GB has nothing to do with defining a class such as "Person".

So, you can use a class to define a relation, but not to define the type Relation, if I understand correctly. Since I've done both, I'm not sure what makes this not possible. I'm sure I only provided a subset of the possible operators for Relation in my class definition -- just those I needed for my purposes, but I'm not sure what wall I would have hit in continuing and defining more operators. Can you clue me in on where the problem comes in? I'm really perplexed by this -- genuinely -- not baiting you at all, so thanks for bearing with me.

>> Then if a variable is declared
>>to be of the type Person, does the 1GB refer to that situation?
> No, it refers to the products that mix classes and tables.

That is what I thought, which is why I used the example of Person (which implements the interface "Relation" and could have a method of showAsTable in it). Where is the problem?

> You only have to review the first chapter of TTM to see that.

I don't have it here right now, but have read it and still don't understand where there is a blunder, although I do see problems with terminology.

>>I guess I'm
>>asking for more precision in stating what practical is being identified
>>the 1GB. It seems like it is a flap about how one person says, for
>>"relation" when they really mean "relation variable" (translated to OO
> It is about existing products, but I don't use such products.
> Fortunately OODBMSs are almost dead, but it is probable that we still
> can find the 1GB in some OR Mappers.

Hmmm. So, the 1GB is only relevant when using OODBMS's and not when using OO languages with RDBMS's? I'm remembering it wrong, then. I'll have to read it again and see if I can understand the issue any better this time.

>>the "cause of many confusions". My question is where the blunder really
>>I think I posted a question on this a year or so ago too and I still don't
>>see a practical blunder
> Because it is probable that you are not using a product that makes
> such blunder.

I'm probaby not using such a product, but I do have an imagination and cannot yet imagine what the blunder is. Even if this is only relevant to "persisting objects" in an OODBMS.

>>Date seems to argue that there is a practical problem in this mix. Do you
>>think there is?
> Of course there is, but only if you use an OODBMS or an OR Mapper.

OK, so not just OODBMS's are the issue-- it is also an issue if you use an OO language and an RDBMS too, right? I just not seeing a problem, either in theory or in practice. cheers! --dawn

> Regards
Received on Thu Dec 09 2004 - 20:42:18 CST

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