ALTER TABLE par_cliente
  ADD COLUMN exibe_botao_transfere_pedido_filial character varying(1);
  
UPDATE par_cliente SET exibe_botao_transfere_pedido_filial = 'S' WHERE exibe_botao_transfere_pedido_filial IS NULL;
  
ALTER TABLE par_cliente
  ALTER COLUMN exibe_botao_transfere_pedido_filial SET NOT NULL;