Re: The IDS, the EDS and the DBMS

Marshall Spight wrote:

> Laconic2 wrote:

>>Marshall Spight wrote:
>>...One of the issues that deserves a whole lot more
>> attention than it gets is this: 
>>"WHY use a DBMS, and WHEN to avoid using one".

Well, then, the two of you. Don't keep us in suspense. When *should* we avoid using a DBMS?

> ...It comes from Zen. The novice looks at the mountain and sees only a mountain.
> The initiate looks at the mountain, and understands that "seeing" is the projection
> of ideas onto the mind. He understands that in a very real sense, his experience
> is not the mountain, but simply his experience. There is not mountain.
>
> The master looks at the mountain and sees a mountain.

Beautiful :-)

> ...A novice writes code. An initiate considers the definition of interfaces,
> carefully considers what algoritms to use, meticulously divides code
> into modules, etc. A master writes code.

>>In fact,  I've seen Oracle databases where a given application has its own
>>schema,  and the schema consists largely of synonym definitions that make
>>database objects in other schemas visible inside that schema.  Functionally,
>>it works like a "subschema".
>>The term "subschema" comes from CODASYL databases.

The RDBMS equivalent of a CODASYL subschema would be a coherent set of views, in a context where the base-tables would not be visible at all - so an application would *need* the views for any data-access. The trivial case would of course be a subschema containing a one-to-one view for every base-table. In fact, in CODASYL environtments these all-encompassing 'sub'-schemata were used for ad-hoc queries.

> In these cases, if the application looks in the catalog, will it see all
> 200 tables in the system, or will it only see the 37 tables it uses itself?
> I've never heard of the latter situation, but maybe it's just my lack
> of experience.
>

>>>>Again,  in expressing what I think is obvious,  
>>>>I don't mean to slam you.  I value your opinions.
>>>I must have missed the part where you slammed me.

Enough kissing, already! ;-)

> Let's talk about views some more. Clearly it's an area
> I have a lot to learn about.
Received on Wed Sep 08 2004 - 01:12:46 CEST