Character Data Types
Character data types are strings of ASCII characters. Upper and lower case alphabetic characters are accepted literally. OpenSQL supports one fixed‑length character data type, character, and two variable‑length character data types, varchar and long varchar.
The maximum size of a character column varies according to the DBMS being accessed. Additional space requirements for character columns are as follows:
• Varchar columns require two additional bytes to store a length specifier.
• Nullable columns require one additional byte to store a null indicator.
Note: Unicode data types are an extended feature of OpenSQL, which means that not all OpenSQL servers support Unicode. If an OpenSQL server supports Unicode, the iidbcapabilities catalog has a row with a cap_capability of NATIONAL_CHARACTER_SET and a cap_value of Y. To see if a particular OpenSQL server supports Unicode, refer to the documentation for that server.