On Mon, Feb 09, 2009 at 06:23:52PM +0100, Vanessa Tejada Muñoz wrote:
I'd like to know which is the filed who defines a disambiguation link/page/element in the database.
There isn't one. MediaWiki:Disambiguationspage is used by MediaWiki when it needs to make that determination (any page transcluding one of the templates there is considered a disambiguation page). On enwiki, you can also check the page for membership in [[:Category:All disambiguation pages]].
For a link, you have to determine if the target page is a disambiguation page. I don't know what a "disambiguation element" might be.