1 – *_(wildcard)
Specifies a wildcard character. If you use the * (asterisk) wildcard character, SQL includes in the editing buffer the number of statements specified in the last SET EDIT KEEP statement. If you do not use the SET EDIT KEEP statement, EDIT * puts the last 20 statements in your editing buffer. If you omit the * (asterisk) wildcard character, SQL includes the last statement issued in the editing buffer.
2 – number
Specifies the number of previous statements you want to edit, up to the number specified in the last SET EDIT KEEP statement. If you specify zero as the number, then SQL does not include any statements in the editing buffer. If you omit the number argument, SQL includes the last statement issued in the editing buffer.