PREHOOK: query: DESCRIBE FUNCTION isnull
PREHOOK: type: DESCFUNCTION
POSTHOOK: query: DESCRIBE FUNCTION isnull
POSTHOOK: type: DESCFUNCTION
isnull a - Returns true if a is NULL and false otherwise
PREHOOK: query: DESCRIBE FUNCTION EXTENDED isnull
PREHOOK: type: DESCFUNCTION
POSTHOOK: query: DESCRIBE FUNCTION EXTENDED isnull
POSTHOOK: type: DESCFUNCTION
isnull a - Returns true if a is NULL and false otherwise