Scanning of composite types -- is it possible? #3148

CREATE TABLE  foos (
    id BIGSERIAL PRIMARY KEY,
    title TEXT,
    description TEXT
 );

CREATE TABLE IF NOT EXISTS foos_history
(
   id           BIGSERIAL NOT NULL,
   foo_id BIGINT NOT NULL,
   changed_at   TIMESTAMP DEFAULT timezone('utc', now()) NOT NULL,
   new_value    foos,
   operation    TEXT NOT NULL
);

CREATE INDEX IF NOT EXISTS idx_id_time ON foos_history (foo_id, changed_at);
CREATE INDEX IF NOT EXISTS idx_time_id ON foos_history (changed_at, foo_id);

CREATE OR REPLACE FUNCTION foos_history_func() RETURNS TRIGGER AS
$foo_history$
BEGIN
   IF (tg_op = 'DELETE' OR tg_op = 'UPDATE') THEN
       INSERT INTO foos_history (foo_id, changed_at, new_value,
                                       operation)
       SELECT old.id, timezone('utc', now()), new, tg_op;
   ELSEIF (tg_op = 'INSERT') THEN
       INSERT INTO foos_history (foo_id, changed_at, new_value,
                                       operation)
       SELECT new.id, timezone('utc', now()), new, tg_op;
   END IF;
   RETURN NULL; -- this is an AFTER trigger. Return result ignored.
END;
$foo_history$ LANGUAGE plpgsql;

-- NOTE: TRUNCATE cannot be triggered on with a row level trigger
-- and will not be saved in history currently.
CREATE TRIGGER foos_history_trigger
   AFTER INSERT OR UPDATE OR DELETE
   ON foos
   FOR EACH ROW
EXECUTE FUNCTION foos_history_func();

-- name: ListFoosHistory :many
SELECT * FROM foos_history WHERE
    (sqlc.narg(filter_id)::bigint IS NULL OR sqlc.narg(filter_id)::bigint = foo_id)
    AND (sqlc.narg(start_timestamp)::timestamp IS NULL OR changed_at >= sqlc.narg(start_timestamp)::timestamp)
    AND (sqlc.narg(end_timestamp)::timestamp IS NULL OR changed_at <= sqlc.narg(end_timestamp)::timestamp)
ORDER BY
    id
LIMIT @limit_
OFFSET @offset_
;