update all sequences with some value in postgresql

inc-all-seq.sql

create or replace function update_all_seqs(inc integer) returns void as $$
DECLARE
    r pg_class%rowtype;
    i name;
    isit integer;
BEGIN 
	FOR i in SELECT c.relname from pg_class c where c.relkind = 'S' LOOP
		isit := POSITION('pv_' in i);
		IF (isit = 1) THEN 
			execute 'select last_value from visionr.' || i into isit;
			execute 'alter sequence visionr.' || i || ' restart with ' || (isit+inc);
			RAISE NOTICE 'update d(%)', i::varchar;
		END IF;
	END LOOP;
END;
$$ LANGUAGE plpgsql;

select f();