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

On 15 Nov 2004 06:36:52 -0800, lajos.nagy_at_gmail.com (Josh Hewitt) wrote:

>However, when you add a getOrders() method to your User class
>things do get complicated.

Indeed, when you add something like that, you are starting to manage the database from the application, which is a great blunder that is not Date's 1GB.

>In my opinion, the 'impedance mismatch' between relational DBMSs
>and OO languages comes into picture only when we want to map object
>graphs to relational tables.

The impedance mismatch is inherent to the languages because they don't allow relation variables.

You can not match a relational database if you don't have relations.

>This might be the explanation why your example of a simple User class that
>maps to a User relation works perfectly in practice.

An User class can't map to an User relation because it is an absurd to map types to variables or values (Date's 1stGB).

An unidimensional collection of User objects maps to an User relation. This is perfectly possible and it is not a great blunder.

> Although you still have to do some
>(more or less) manual mapping to construct User objects from result set
>rows and to store User objects to the relational DBMS.

Indeed, and without any gain.

Regards Received on Mon Nov 15 2004 - 16:17:22 CET