Re: Unknown SQL

Bob Badour wrote:
> >Ideally object databases do not need specialized implementations.
>
> Object languages expose physical implementation details to programmers.
> Subsequently, when object languages differ, databases based on them must
> differ as well. Your 'ideal' was long ago defined out of existence.

Most object languages are very similar. You have classes, simple datatypes, arrays and inheritance. Lower level API classes that would typically be persisted like collections are also similar.

The database API would be exactly the same.

If you really need mixed language development (Do you do mix ORACLE- and Sybase-SQL-development ?) you would use class translators.

> >This is where we are headed:
> >- no need to derive from a specific class
>
> Who cares?
>
> >- no need to implement a specific interface
>
> So?
>
> >- support for all language constructs like two-way pointers, collections,
> >hashmaps
>
> And your point would be... ?

There simply is no (zero, nothing, rien, kein) administration work or maintenance work necessary to persist objects. The database engine analyzes classes automatically.

There is no need for normalization work, creating and maintaining tables, thinking about keys, no strings within code, no mismatch between inheritance hierarchies and tables.

The more complex your object model is, the higher the performance advantage on inserts and navigation will be.

> Provided you deal with a single programming language as implied by your
> 'respective programming language' statement above, and provided all OO
> databases for that language use the same OID format internally. You don't
> seem to get the fact that the value 10 remains constant no matter how one
> represents it. Philip gets it.

Yes of course I do.
You don't seem to get the fact, that object databases have to care about OIDs at all. They won't even need to see the value 10. Why care about internal linkage, if it does not provide any needed information?

> >Of course there are areas where standardization work will be necessary:
> >1.) Persistency callback functions
> >2.) Queries
> >3.) Locking and isolation level behaviour
>
> How will any of the above address the fact that the value 10 remains the
> same among all value based systems including all relational databases?

???
Why care about the value 10?

> How will any of the above address the fact that OIDs,
> ie pointers, are necessarily implementation specific.

The implementation specific work is done by the database vendor. It will be transparent to the user of the object database.

Kind regards,
Carl

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Carl Rosenberger
db4o - database for objects - http://www.db4o.com