SELECT util.search_path_append('util');

UPDATE :table SET
denorm_kingdom = "Kingdom"
WHERE denorm_kingdom != "Kingdom"/*implies both NOT NULL*/ -- applies to 1 row (PLANTCONCEPT_ID 92372)
; -- rerun time: 0.5 s ("710.176 ms") @starscream; runtime: 2 s ("2211.789 ms") @starscream

UPDATE :table SET
denorm_genus = trim(denorm_genus, '{}') -- applies to 6 rows
WHERE denorm_genus LIKE '{%}' -- applies to 6 rows
; -- rerun time: 0.5 s ("492.670 ms") @starscream; runtime: 0.5 s ("543.942 ms") @starscream