[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Re: XML Database
Kenji, > We sometimes encounter a client who belives that making > XML(SGML)Documents means making Database. What they believe is if > they make their document in XML they will easily be able to find > information in it, and to manage it. > > We are having hard time to make them understand if they need data > base, they have to develop a data base system. > Then, they loose interest in XML(SGML). What they want is easy and > versitle data base system. As others have said, XML is an interchange format - i.e. the stuff that matters when you either transport information, or when you wish to file it without knowing/caring how it is going to be used in the future. It's also a "markup language", of course. > Do you have any good ideas to show the advantage of XML as the data > base format to this kind of people? Raw speed. > Are there any experience or information regarding XML(SGML) data base? Very, very tentatively, I'd say: yes, I've been doing some work in this area the explore the field. I'm the author of a cross-platform storage manager for structured data, called "MetaKit". Right now, there are interfaces for C++, Tcl, and Python (the library is written in C++). I wrote a small utility called "mk4xml", which reads any XML document into a flattened tree-structure (using "expat") and saves that as a MetaKit datafile. As an experiment, I wrote a small Tcl script called "ot_conf.tcl" which takes such a MetaKit datafile, generated by mk4xml from the "ot.xml" (Old Testament) document, and converts it into a nested datastructure that matches this specific document's DTD. You can see some of this in motion at: http://www.equi4.com/metakit/xml/ but as you'll see this is proof-of-concept stuff at this point... there's not even a decent index page there yet. There's a "summary.tcl" script which collects some stats on files generated by "mk4xml". The results are interesting: File sizes: ot.xml 3.9 Mb mk4xml ot.xml result: 4.1 Mb ot_conv.tcl result: 3.1 Mb Access speeds: ot.xml (take your pick, parse in seconds up to minutes) mk4xml ot.xml result: opens in 1.4 sec (on a fast PII/400) ot_conv.tcl result: opens in 60 mSec (on same system) Access method: ot.xml SAX/DOM, usually linear scan mk4xml ot.xml result: random access by element/subelement/... ot_conv.tcl result: random access by book, chapter, verse > Are there any good XML data base in commercial basis? Being such a general question, I do not feel qualified to answer this. > If there is such Database, how much will it cost? My first reaction would be: could be anything. The current market for XML software runs from free to 5-digit dollar amounts, and commercial businesses being what they are, the rule in a new field like XML is very likely to be "anything you can get away with"... oops, that's not a nice thing to say, let me rephrase that as "what the market will bear". MetaKit is free for non-commercial use, with binaries available for Unixes, Windows, Mac, VMS, and royalty free source code licenses for commercial use, at a price level which seems to cause some people to not take it seriously... see the website for details. Be your own judge. Feel free to contact me for further details. At this stage, suggestions and comments are most welcome - as I said, it's just a sneak preview... Regards, Jean-Claude ________________________________________________________________________ Jean-Claude Wippler MetaKit home page - http://www.equi4.com/metakit/ Equi4 Software "Portable database software for a changing world" xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev@i... Archived as: http://www.lists.ic.ac.uk/hypermail/xml-dev/ To (un)subscribe, mailto:majordomo@i... the following message; (un)subscribe xml-dev To subscribe to the digests, mailto:majordomo@i... the following message; subscribe xml-dev-digest List coordinator, Henry Rzepa (mailto:rzepa@i...)
|
PURCHASE STYLUS STUDIO ONLINE TODAY!Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced! Download The World's Best XML IDE!Accelerate XML development with our award-winning XML IDE - Download a free trial today! Subscribe in XML format
|