Talk:Object-relational impedance mismatch

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This page has much interesting information, but fundamentally flawed by the mix-up between SQL and relational. I have thus renamed it and changed most mentions of relational to SQL, but it really should be split between what are specifically SQL problems and what are OO misunderstandings of the relational model in particular or database administration in general.

OO is poorly defined, or at least inconsistently defined. It is hard not to have a misunderstanding of something that is poorly defined. It seems everybody's psychology about OOP is different from each other. Further, I believe that domain types and relational are or should be orthogonal. As long as domain types follow conventions that relational expects, there is no reason for tight integration between the two. If you marry the two, then you risk favoring some domains at the expense of others when choosing relational. Also, which are problems specific to SQL but not relational in general?

Nulls for one thing; repeated rows in the results for another. Read the many essays of Date (who worked with Codd to create the relational model) for more on why SQL is a bad implementation of the relational model. -- Derek Ross | Talk 05:08, 17 August 2006 (UTC)

"It has been argued that trying to inherit from a database record is a mistake." - This seems to me to be typical 'weasel words'. See http://en.wikipedia.org/wiki/Wikipedia:Avoid_weasel_words .

[edit] Uniqueness Observation

Uniqueness Observation — Row identities (keys) generally have a text-representable form, but objects don't require an externally-viewable unique identifier.

Externally-viewable they may not be, but unique identifiers are always present internally (e.g., pointers, reference values). They must be valid at least during execution, when OO is actually in effect. Doesn't that count? Cheers. --189.25.93.26 19:47, 2 July 2007 (UTC)

[edit] Allegedly

The fourth paragraph starts as follows: Access to objects in object-oriented programs is allegedly best performed via interfaces.... This is wrong use of the word allegedly, because that word implies that the statement is actually not true (as in he allegedly committed a murder, then they think he did, but in fact he did not), while from context it seems the intended meaning is something like probably, usually, generally or according to most textbooks. But since I was reading this to try to learn something, I am not savvy enough on the subject to make good changes myself. Please help out :) Dtuinhof (talk) 09:09, 14 March 2008 (UTC) Dtuinhof (talk) 09:09, 14 March 2008 (UTC)