Re: S.O.D.A. database Query API - call for comments

From: Lee Fesperman <firstsql_at_ix.netcom.com>
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

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