More than ever we use and relay on search engines to find things in the Web (i.e. Google, Bing, etc).
Oracle has a history of changing link around (OTN, etc..) and not maintaining an internal redirection list or even issuing for a time the HTTP 301 Moved Permanently (with the new URL) to web clients (including the crawlers of the search engines).
So we keep on getting oracle site pages in the first places of the search answer list but with no information and search in oracle site means you have to logon. OK using the "Single Sign-On" it's free but even so it's for the normal web user a "wall" and they will leave.
An example of this (at the time of the post) ? Easy!
Search: "Java Stored Procedures" and you will get a link to
http://www.oracle.com/us/technology/sample_code/tech/java/jsp/index.html in the first page (OK it depends on search engine features, country and if you logged on , but should be there)
That link will get you to a page "Error Page 404 - We're sorry, the page you requested was not found." :-(
You can try to use the "Internet Archive: Wayback Machine" but will no success :-(
A possible workaround? Try to check the cache result of Google for the link if available.
Why can't Oracle (a "Database also" Company) maintain their links or keep a database (!) of old link-> new ("related" if not equal) link and search on it when it would display the "Error Page 404" and or redirect the person to that page or show in that 404 page the new link (or list of links)?