XML or a (relational) database for HUGE files

[hakhan]

Hello,

I need to store huge(+/- 100MB) data. Furthermore, my GUI application
must select data portions from these huge data files in order to do
some post-processing. I wonder in which format I should put my data
in? XML or just a (relational) database? Or should I use an XML
database (native or xml-enabled?)??? I am a little bit confused ....

If I'd put the data in XML files, then loading the entire XML tree in
memory(DOM) would result to a performance problem. However, SAX could
be the solution. But I am afraid that I have to parse my XML files
every time I do a query on the data.
How would the performance be like if I put the XML files in a XML
database?
Or would dividing the XML file in smaller XML files be a considerable
solution?

IS XML a solution for my problem or should I just use a relational
database?

Do you have any other ideas? Any suggestions by giving links to
articles and web sites are welcome!

Here are some factors that count for our case:
- the target application only has to view and query the data (adding
and updating data is not necessary;
- the data is semi-structured and;