create table task_statuses (
  key text primary key not null,
  created_at timestamptz not null default now()
);

insert into task_statuses (key) values ('submitted');
insert into task_statuses (key) values ('runnable');
insert into task_statuses (key) values ('starting');
insert into task_statuses (key) values ('pending');
insert into task_statuses (key) values ('running');
insert into task_statuses (key) values ('failed');
insert into task_statuses (key) values ('succeeded');