SQLite Forum

Efficiency of updates versus replace when using the JSON1 extension functions.
UPDATE will never change the rowid, unless the rowid is mentioned in the SET field list. The number of fields int the table is irrelevant. SQLite may optimize the internal table away if the WHERE clause can be shown to limit the update to a single row, i.e. all the fields of any unique key are limited by an equality constraint.

UPDATE t SET b = ? WHERE id = ?;

is an example.