DB or XML or both for storing large amount of data???

[Raseswari Achanta]

Hi All,
This is the problem related to where to store large amount of data. Either in XML or in DB???
I need the pros and cons of both XML and DB. And I heard that we can as well use both xml and db for storing data. But what are the advantages of using that(XML+DB) as I'm very novice of using xml with db. In which situation we go for both xml and db???
Hope I get the reply to my question from u friends..
Thanks in Advance
Regards,
Raseswari.

[This message has been edited by Raseswari Achanta (edited October 12, 2001).]

[Mapraputa Is]

XML is non-proprietary data format great for exchange data between applications.
XML can be used (perhaps) to store small amount of data if you do not need functionality provided by DBs:
transactional integrity,
security
authentication
concurrency control
data validation and conversion
search mechanism...
but it was not designed for this proposal. And certainly it is not a good choice for storing large amounts of data. In this case you are better off with DB.
"In general, XML is the right choice when you need to
* Share enterprise data. Using XML is a great way to share data because it eliminates application dependencies.
* Transfer transient data. XML is easy to transfer across the Internet.
* Collect and work with meta data. If you're cataloging Web content, for example, XML enables easier Web searches.
* Conduct client-side rendering of Web pages with Extensible Style Language (XSL). This approach can relieve some of the burden from your Web server.
In general, XML is NOT the best choice for
* Updating, storing, and retrieving large amounts of data on disk. These tasks best suit a relational database management system (RDBMS).
* Working with internal data structures that aren't exposed to outside applications. Iterating through XML is much slower than iterating through an ADO Recordset object, and the ADO Recordset object has a slightly easier programming model than the XML Document Object Model (XMLDOM).
* Use as an argument in a method call. XML isn't always a bad choice in this case. The main drawback is that you need to instantiate an object (XMLDOM) inside the method to access the XML fields and records. You might find it simpler to pass in a multidimensional array, ADO Recordset object (which is self-marshalling), a string, or even a user data type (UDT) or structure (in C programming)." http://www.sqlmag.com/Articles/Index.cfm?ArticleID=8875

[Raseswari Achanta]

Hello Mapraputa,
Thanku for giving me the valuable information abt using xml for storing large amt. of data. To some extent my doubt got clarified.
But still the doubt of when to use both xml and RDBMS isn't clarified? And storing small amount of data in the sense upto howmuch data we can store and retrieve from xml? We already used xml files in the personalization screen for storing, retrieving as well as updating the data. In that searching of the data was also done. And we faced no problem with that as we maintained xml files for the single user separately.
But for storing multiple user info how far is this helpful? And in our application a provision should be provided for searching the data according to the user name. In this constraint I got a doubt upto howmuch of data we can store in xml files.
Plz. help me out in this aspect.
Once again thanku for the detailed explaination given.
Regards
Raseswari.