Using xml files for a web project.

The main question here is the following,
"Is it safe - ok - faster - lighter for the website (call it as you wish) to use an XML from server file or url directly and not storing them in the db, in order to get website entries?"

E.g.:
Let's say we have a website with multiple users in it and some of them having some blog posts. Is it ok and the most important, safe to use an XML to parse the data?


P.S.: I couldn't find any related subjects about this so i thought that it would be a good discussion subject for some newbies (like me )
Thanks!

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