implement INFORMATION_SCHEMA.PARAMETERS.PARAMETER_DEFAULT column

DELIMITER ||

CREATE OR REPLACE PROCEDURE p(a INTEGER DEFAULT 9999)

    DETERMINISTIC

BEGIN

    SELECT a;

END ||

DELIMITER ;

SELECT * FROM information_schema.PARAMETERS WHERE SPECIFIC_NAME = 'p' \G

*************************** 1. row ***************************

        SPECIFIC_CATALOG: def

         SPECIFIC_SCHEMA: test

           SPECIFIC_NAME: p

        ORDINAL_POSITION: 1

          PARAMETER_MODE: IN

          PARAMETER_NAME: a

               DATA_TYPE: int

CHARACTER_MAXIMUM_LENGTH: NULL

  CHARACTER_OCTET_LENGTH: NULL

       NUMERIC_PRECISION: 10

           NUMERIC_SCALE: 0

      DATETIME_PRECISION: NULL

      CHARACTER_SET_NAME: NULL

          COLLATION_NAME: NULL

          DTD_IDENTIFIER: int(11)

            ROUTINE_TYPE: PROCEDURE