Rewriting even a sublist generates unnecessary updates—on both the table and associated indexes. (While the article doesn't specifically describe using sublists

Rewriting even a sublist generates unnecessary updates—on both the table and associated indexes. (While the article doesn't specifically describe using sublists, this is likely for pedagogical reasons: he doesn't include surrogate keys either. The pathological case of a full table rewrite on any update would be avoided in any event.) As for storage, the rational datatype described in the submission has the same size as a BIGINT (64 bits), so there's no storage disadvantage there.