ALTER TABLE task
  ADD COLUMN IF NOT EXISTS committee_id BIGINT REFERENCES committee(id) ON DELETE SET NULL,
  ADD COLUMN IF NOT EXISTS agenda_item_id BIGINT REFERENCES meeting_agenda_item(id) ON DELETE SET NULL;

CREATE INDEX IF NOT EXISTS idx_task_committee_id ON task(committee_id);
CREATE INDEX IF NOT EXISTS idx_task_agenda_item_id ON task(agenda_item_id);