You are talking about the root seed list (the NS records for the root label .) - essentially the anycast IPv4/6 addresses for the 13 root servers. This file is

You are talking about the root seed list (the NS records for the root label .) - essentially the anycast IPv4/6 addresses for the 13 root servers. This file is provided in the first section of the linked page. The second file on the page contains the actual current root zone, which is a 2 MB file containing all the delegation entries for TLDs (like com., org. and de.) immediately below the DNS root (.). This is what the article is talking about caching locally at your ISP's recursive name server. The whole global DNS can never be downloaded or even built as a local database due to its distributed nature, and also for technical reasons. Below the root zone at TLD level (like com.) there is no way to enumerate all the individual registrations (like google.com., ycombinator.com., microsoft.com. etc) You always query for a specific individual name + record pair, instead of being allowed to download the entire zone. So even if you somehow would be able to contact every authoritative DNS server on Internet at some point in time, there is no standard query to ask them to give you all their records, making building a full local copy of the global DNS database impossible.