The VARCHAR2 data type does not pad data with trailing spaces. However, Oracle CHAR does pad with trailing spaces. For example, in a CHAR column 20 characters wide, the entry MA includes the two characters and 18 spaces. Your application will find the entry only if a WHERE clause searches for the string that includes MA and the 18 spaces. If the column is a VARCHAR2 column, your application will find the entry if it searches for the two characters. The VARCHAR2 data type is more consistent with the OpenEdge CHARACTER data type.
