why hierarchy?

From: JOG <jog_at_cs.nott.ac.uk>
Date: 26 Jul 2006 05:27:22 -0700
Message-ID: <1153916842.649074.95220_at_m79g2000cwm.googlegroups.com>

I spoke in a recent thread of my distaste for XML from a theoretical standpoint (nevermind the processing overhead of using an XML parser within any even vaguely time critical application). Well I wanted to highlight why I made the statement. Below are 4 examples of recent quotes concerning XML databases from academia, nevermind the business world:

"XML is capable of holding information that is far richer in structure
than the rows and columns of a relational database. If you don't feel that rows-and-columns are constraining you then either you don't really need XML at all, or you've become locked into a way of thinking that because tables are the only thing you can store, tables must be what users want."
- Michael Kay, xsl-list mailing list

"In the wild (that is, in documents, reports, and program data
structures as they are encountered in daily life), information takes forms rather different from third normal form. XML arose from efforts to represent documents in a device- and application-independent way, and it reflects the complexity of documents and their stubborn refusal to fit into tabular form."
- C. M. Sperberg-Mcqueen, ACM Queue 2005

"The popular schema languages are generally too simplistic to model the
increasingly complex and dynamic information structures. Because of this mismatch, in some cases, even if schemas exist, the result is unfortunately the same as in the previous cases: "rich structure" often translates in practice to "no structure." For example, the commonly used relational and object-oriented schema languages lack adequate support for describing alternative structures (e.g., authors or editors for books), and for conditional and correlated structures." - Daniela Florescu, ACM Queue 2005

"In XML, data can have an elaborate and intricate structure that is
significantly richer and more complex than a table of rows and columns. Calling this semi-structured is misleading, just as it would be to describe DNA molecules as semi-structured because they are less simply regular than those of table salt. XML seeks to make possible capturing and expressing the structure of the data as we understand it, without forcing it into a too-simple structure." - C. M. Sperberg-Mcqueen, ACM Queue 2005

The last 3 are from a top notch publication, and I find this return of focus to hierarchical models since 1995 extremely frustrating. Received on Wed Jul 26 2006 - 14:27:22 CEST

Original text of this message