One more follow up, how the inter table `links` in your schema was draw using DB Designer, or it is using external program?
It was entirely drawn using DB designer.
If you'd like, you can get the raw data file used to generate the image from http://files.nickj.org/MediaWiki/mediawiki-dbdesigner-schema-data.xml (I tried uploading this data file Commons, but '".xml" is an unwanted file type List of allowed file types: png, gif, jpg, jpeg, xcf, pdf, mid, sxw, sxi, sxc, sxd, ogg, svg, djvu' http://commons.wikimedia.org/wiki/Commons:File_types )
Then install DB designer, run it, go File -> Open, point it at this XML file, and what you see when it loads should match the image.
-- All the best, Nick.