I am working on a project(asp.net 2.0)

I have to take a decision between XML or SQL Server 2005

Problem:
1) In future 1 million users will access the site.
2) If i store data in xml files with an "index xml file" to track the files, reading bulky index file(suppose 250-700GB) is very difficult when million people access the site and search content.
3) Project owner requirement: Response to user search query must be 1-2 seconds maximum.
4) What will be the hardware configuration for such a bulk access?


Please help.

No question: you should be using a database engine. You are building a "big boy" application that needs a "big boy" data storage platform.

-Peter
compiledthoughts.com

It seems to me you have to make two decisions: what data model to use, and what storage engine to use. It sounds as if it's appropriate to use XML as your data model and a database engine for data storage, so you should do that: they aren't in conflict. Whether SQL Server 2005 is the best database engine for storing XML is another question.

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference