find corrupted database fields in postgres

pg_search_corrupt_field.sql

DO $f$
declare
    read_data TEXT;
    bad_id INT;
begin
FOR bad_id IN SELECT id FROM <TABLE_NAME> LOOP
    begin
        SELECT <TABLE_FIELD>
        INTO read_data
        FROM <TABLE_NAME> where id = bad_id;
        read_data := substr(access_data,1000,2000);
    exception
        when others then
            raise notice 'data for row with id % is corrupt', bad_id;
            continue;
    end;
end loop;
end;
$f$;