Values can be specified ( extended value spec ) by specifying values ( value spec ) or with one of the keywords DEFAULT or STAMP.

value spec

• DEFAULT keyword
  DEFAULT identifies the default value for the column in a CREATE TABLE statement or ALTER TABLE statement. DEFAULT cannot be used to specify values if one of these values is not defined.
  The DEFAULT keyword can be used in the following SQL statements:
  INSERT statement
  UPDATE statement
  The DEFAULT keyword can be used in a DEFAULT predicate.
• STAMP keyword
  The database system is able to generate unique values. This is a serial number that starts with X'000000000001'. The values are assigned in ascending order. It cannot be ensured that a sequence of values is uninterrupted. The STAMP keyword supplies the next value generated by the database system.
  The STAMP keyword can be used in the following SQL statements (only on columns of the data type CHAR(n) BYTE with n>=8, see DEFAULT specification):
  INSERT statement
  UPDATE statement
  If the user wants to find out the generated value before it is applied to the column, the following SQL statement must be used:
  NEXT STAMP statement