Friday, March 23, 2007
Wednesday, March 14, 2007
We all know that the following limitations in DTD pushed for a new schema standard.
- DTD is expressed in its own language. We need to master another set of notations to work with DTD.
- We have no way to specify data types and data formats.
There’s been a schema war among industry experts for a quite some time. You won’t disagree with me that XML schema enjoys a wider acceptance in the current software market (at least in the areas I am working on). But, which one is better, XML Schema or RELAX NG? I being a novice in this area, went on to browse through old archives at IETF XML USE newsgroup.
I agree that RNG is easy to understand with this excellent tutorial. At the same time, I was able to grab the concept behind XML Schema (which I currently use) quite easily. On the surface, it seems to me that the major difference lies in the style: while XML Schema categorize patterns into distinct components such as elements, attributes, complex/simple types, etc., RNG introduces generic patterns. I need to dive deep into both schemas in order to provide an objective and practical comparison. Wait..what about Schematron? I like the fact that it (schematron) does not impose any ordering of sibling elements (in contrary to XML Schema and RNG), which is quite valid and sufficient for data centric applications.
Friday, March 9, 2007
Although we see a rise in billionires, the question we need to ask is 'has the condition of the poor improved over the year?' I think the opposite has happened. One thing these people can do is to translate their success to more jobs, striking a balance between the rich and the poor.
Wednesday, March 7, 2007
Here's a summery I jotted down.
- rise of XML technologies - XSLT (XQuery and XForms are still a couple of years out from wide adoption) (and of couse job listings)
- XHTML becoming "standard" at least at the corporate level
- rise in demand for ontologists and RDF specialists (harnessing the ability to create metadata structures)
- transitional shift towards the declarative web architecture
- rise of JSON, E4X, Linq (unlikely that these languages will replace XML)
- XML Binding languages will be the next arena of development (and contention) - the ability to assign a behavior to an XML tag is profoundly useful, and provides both the bones of the declarative structures and the muscles of the imperative one, while keeping the presentation layer safely off to one side (AJAX).
- more commercial level XSLT2 transformations
- the interesting things being done in XML are increasingly occurring in the application and vertical markets
- HL7 in the health care field
- GML in the mapping and geographical location space
- XBRL or UBL in the business space
- while RDFa may have a fairly major hill to climb in terms of adoption, it will likely end up becoming integral to the semantic web fairly soon
Link: where is xml going?
Isn't this a good example about 'history repeats'?
The idea of declarative programming has been around for about half a century. Until I started to learn ML last year, I thought I knew fairly well about programming languages, which turned out to be wrong. Why is declarative programming in the form of Lisp, Haskell, ML, etc not commercially successful these days? The main reason might be that compared to imperative languages such as C, C++, Java, etc. it's harder to come up with a solution, at least initially or it may be that I am so used to imperative languages that I couldn't do away with it initially. Is there a marketing glitch attached to it as well (for not succeeding)? Having said all this, now we see a rise in XML declarative behavior bindings..isn't it a good example of 'history repeats'!
Read an interesting
Here’s the abstract of Microsoft TerraServer: a spatial data warehouse, published in Proceedings of the 2000 ACM SIGMOD international conference on Management of data.
TerraServer demonstrates that general-purpose relational database technology can manage large scale image repositories, and shows that web browsers can be a good geo-spatial image presentation system.