Re: S.O.D.A. database Query API - call for comments
Date: Sat, 21 Jul 2001 18:02:09 GMT
Message-ID: <3AF3B6AB.2F54_at_ix.netcom.com>
Carl Rosenberger wrote:
>
> Lee Fesperman wrote:
> > FirstSQL/J uses SQL. A class is just another database type for a column.
The only change
> > to SQL is to allow you call the methods of a column object and a 'new'
operator for
> > creating objects.
>
> With your approach there is no possibility for server-side query
> optimization. Every single object needs to be instantiated completely, just
> to evaluate a simple member. This will perform very badly.
Not really. Column objects are not intended to be complex application objects but instead user-defined types. They tend to be small, and member references are minimal. Serialization works well in this circumstance. Caching also helps.
> > > Do you use Java serialization to store objects?
> >
> > Yes, in columns.
>
> What do you do, if user classes are modified?
Only 'serialization-safe' modifications can be done. This is less of a problem because of the way objects are used.
> Serialization and deserialization is very slow and produces lots of storage
> overhead by the way.
See above. Not a problem in this instance.
> What happens if:
> - object A has a member B
> - object A is stored to one column in one table
> - object B is stored to another column in another table
> - one query delivers object A
> - another query delivers object B
> How many instances of object B will be produced?
2 instances of B will be produced. In FirstSQL/J, we don't want the member B in object A
to change when the separately referenced object B is changed. Linking of entities is
through relational techniques. Navigating through member references in objects adds
unneeded complexity to a query language.
You see we are working towards evolving database, within a relational framework.
--
Lee Fesperman, FFE Software, Inc. (http://www.firstsql.com)
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Received on Sat Jul 21 2001 - 20:02:09 CEST