Media file location in database

Hi all,

I have Umbraco 4.7. When I created files (PDF, images and so on) in my media library I could see all the files are in file system.

However when I searched cmsContentXml table, I found some entries in <image> or <file> Xml, but not all the files are found in this table.

The reason I am asking is I need to move /media folder to somewhere else, and I need to globally update all media file reference path in tables.

Anybody could give me a headup, which talbes I should look into?

Thanks

Hardy