BYTE and TEXT
The only default value valid for a BYTE or TEXT variable
is NULL. The following example defines a TEXT global variable that
is called l_blob:
CREATE PROCEDURE use_text()
DEFINE i INT;
DEFINE GLOBAL l_blob REFERENCES TEXT DEFAULT NULL;
...
END PROCEDURE
Here the REFERENCES keyword is required, because the DEFINE statement cannot declare a BYTE or TEXT data type directly; the l_blob variable is a pointer to a TEXT value that is stored in the global environment.