Re: Object-relational impedence

From: S Perryman <>
Date: Thu, 06 Mar 2008 17:39:12 +0000
Message-ID: <fqpa85$np9$>

Bob Badour wrote:

> S Perryman wrote:

>> Yagotta B. Kidding wrote:

>>> 'Match' is cool,  but what about more interesting operations like 
>>> 'project(join(R1,R2)), R1.a1, R2.b3)'  where R1 is a set of 
>>> <c,a1,a2,a3> tuples and R2 is a set of <c, b1,b2,b3> tuples  ?  How 
>>> do you express that in your fav OO language ?

>> As I have said on numerous occasions, the semantics of "joins" are an
>> issue for OO (specifically the fact that in OO any of the "values" of
>> c/a1..a3/b1..b3 could be a computational operation and not a data value
>> etc) .

> How is that any different than a relational view? Whether the data is > calculated or stored directly is irrelevant.

I know this should be true, but something in my head keeps screaming "its' not that simple !!!" . :-( :-)

I feel that thoughts of specific impls of both RDBs and OO prog langs are perhaps preventing me from stepping back and seeing things cleanly.

But I am interested in exploring the notion of an 'ADT join' and how it might be implemented by an OO prog lang.

Steven Perryman Received on Thu Mar 06 2008 - 18:39:12 CET

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