Re: Resiliency To New Data Requirements

dawn wrote:
> Yes, I've read those terms. I do understand the use of "unstructured"
> within an attribute value, such as an attribute whose value is a
> document. That doesn't make the whole unstructured. The fact that a
> database holds music doesn't make the database any less structured.
> There can be a structured database that includes unstructured attribute
> values.

The word "structured" here is a waste of time. To use a programming analogy, a 10,000 line program of imperative spaghetti code has structure - one could argue too much, of the graph sort, while too little of the module sort or function sort. "Structured" as a boolean (or fuzzy-logic) function isn't the point - what matters is which structures we're discussing.

"Unstructured" just means uninterpreted in a given context, and that means a type or domain in the control of the users.

> R(URL, html, foreignKeyList)
>
> That's some structure, right?

Sure - without the pesky underlying semantics. Each user of a piece of such a "structure" is going to need to layer semantics atop this, with functions to decompose and combine pieces of it.

> For the subset of the web with xhtml
> backed by a schema, we would perhaps be able to show more structure.

None of the rules you'd find useful on any cohesive component of this structure can be expressed using the structure. "Showing more" structure is just a matter of derivation and interpretation (like showing that a point in time is "decomposable" into a month, day, and year in the Gregorian calendar).

> Maybe I'm misunderstanding the use of these terms, but I reallly,
> really dislike the term "semi-structured" for data that has a
> structure. --dawn

"Structured" means, roughly, having a form or pattern of composition (assumes component parts). In that sense, every "node" of a structure is equally unstructured (all domains are equal, and while each can have functions which evaluate to values of some type, these functions are all orthogonal to the structure).

• erk