|SUMit Roster Software > Nut's Weekly > July 2001 > Object Id||Nederlands · Search...|
|Monday, 2 July 2001||May 2001 June 2001 Knot Cartrain Compiler Push August 2001 September 2001|
Does a modern database need
the third normal form?
Need the Third Normal Form?Yes! Yes! Yes! You do need the third normal form, for every database design.
The database designer must perform data analysis, even when using object ids. Object ids are just a possible technical implementation, but please let it be of an working logical model. Object ids are not a valid excuse to just skip data analysis. Behold: you need it for an object model too. Object model and database design are not identical twins. The are just half-brothers with a common parent: a conceptual model (for example an ERD).
Every object unique by own object idYes. In an OO world every object is unique, just like it is in the real world. However this is a fake reason, an irrelevant argument.
With object Ids the database looks just like an objectbase, but is that important? Thesis: Object Ids are just good for internal usage in the object layer. Please keep them hidden from the user interface and exchanges with other systems.
Object ids are so elegantly genericYes, how beautiful. So, what is it good for? Why is it an advantage to have something generic? If being generic truly is such an advantage, please take it one step further: Create a generic table with the following columns:
Fast joinsHmm. For performance no join is much better than a
And how do you avoid joins? Have a look at denormalisation. In third normal form keys are denormalised in a very natural way, available without join. And it is exactly this key information that often has the highest frequency of usage, so the biggest impact on the performance.
Yes, yes, you can still denormalise that key information. And yes, you can add an extra index for uniqueness. So, where is the advantage of the object id for the performance??
|Saturday 30 June 2001: Suzanne Piet passed her C diploma in swimming. Congratulations!|
· Object Id
· August 2001
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