Re: Object-relational impedence

From: Thomas Gagne <>
Date: Wed, 05 Mar 2008 09:57:23 -0500
Message-ID: <>

Dmitry A. Kazakov wrote:
> On Wed, 5 Mar 2008 01:10:01 -0600, Robert Martin wrote:
>> <snip>
>> You are confusing OO with static typing. In OO languages like Ruby,
>> Python, or Smalltalk you can pass any object to any function
>> irrespective of type.
> Which is a bad idea.
> Nevertheless you don't need dynamic typing in order to deal with that. You
> could have a class of relations in order to define operations (like join)
> on them. That will give a static type to the result of any join.
At what cost given a similar benefit can be gained without the extra effort?
> The problem is elsewhere. How do I know in *advance* that the result of
> join is a relation of certain narrower kind? Both "statically untyped" SQL
> and "dynamically untyped" fancy languages have no answer to that until run
> time. Note that this is a software design issue.
The result is what it is. If it answers the messages sent it predictably what does it matter?

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Received on Wed Mar 05 2008 - 15:57:23 CET

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