On Tue, 7 Jan 2003, [ISO-8859-1] Juan David Ibáñez Palomar wrote:

>
> But what happens if you reach production and you need
> to add a new view? Then, if you want something efficient,
> you have to change the data structure and to transform
> the existing data to the new model.
>

Unless you're changing the most trivial things with a
relational database backend you typically go through even more
steps! Modify the schema, change your data structures, then
modify all the query snippets that load/modify/store
those data structures.

>
> That's the point. Doing a join of tables is fast enough most
> of the time, and it is more simple. So you use it until performance
> becomes a problem, then you optimize and build your own data
> structures.
>
> Using your own data structures since the beginning just because
> they are faster is the typical problem of optimizing before you
> need it, what only raises development costs.
>

I don't know about you, but I use data structures primarily
for abstraction. They're there from the beginning because it's
The Logical Thing To Do. And if the data structures are not inherently
suited for storage in a relational database, then the elimination of all
the contortions you have to go through to make them persistent
on one actually lowers development time, complexity, and costs.
But yeah, you lose the ability to do completely generic queries.


--
Karl Boehnker
Programmer/System Administrator
University of Missouri - St. Louis