ALTER TABLE rpc_automatica_tabela
  ADD COLUMN dblink character varying(1);
  
UPDATE rpc_automatica_tabela SET dblink = 'N' WHERE dblink IS NULL;

ALTER TABLE rpc_automatica_tabela
  ALTER COLUMN dblink SET NOT NULL;
  
UPDATE rpc_automatica_tabela SET dblink = 'S' WHERE sequencia IN(10, 11);