Re: What is an OODBMS?

From: H. S. Lahman (h.lahman_at_verizon.net)
Date: 01/08/05 

Date: Sat, 08 Jan 2005 15:33:26 GMT

Responding to Frebe...

>>one of
>>the key differences between the RDB view and OO applications. The RDB
>>view is geared to ad hoc data retrieval (i.e., there is no assumption of
>>what data will be selected of why) while the OO view is tailored to very
>>specific problems (i.e., the problem solution defines /exactly/ what
>>data will be selected).
>
>
> Isn't the main reason why the old database paradigm was abandoned, that
> every view has to be tailored to very specific problems? In the
> relational model you don't need to know every future feature request
> when you design your database. Indexes can be added later without
> changing the interface to the applications.

A database provides a service to applications. Since many applications
may need to share the same data for different reasons, modern databases
are geared to optimizing for ad hoc access to the stored data.

However, the applications are solving individual problems so they are
optimized around the particular problem context. The RDB index & search
paradigm is relatively inefficient for individual applications,
especially when the same data is processed repeatedly.

>>If one wants to select from a collection based upon non-identity data,
>>then one will have to have explicit selection logic for that.
>
> Does this logic belong to the "business layer" or the "persistence
> layer"? I just want to check...

The business layer.

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H. S. Lahman
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