-20365 A SIGNALING NAN WAS ENCOUNTERED, OR AN EXCEPTION OCCURRED IN AN ARITHMETIC OPERATION OR FUNCTION INVOLVING A DECFLOAT

Explanation
 A signaling NaN (sNaN) was encountered in an expression,
arithmetic operation, or function. This message could also be issued
because an expression, arithmetic operation, or function involving
a DECFLOAT column or value resulted in an exception. In either case,
the result is a NAN, and an error is issued.

System action
 The statement cannot be processed. In
the case of an INSERT, MERGE, or UPDATE operation, no data is updated
or deleted. If the statement is a cursor-controlled FETCH, then the
cursor will remain open, unless the exception occurred while processing
an aggregate function. If the exception occurred while processing
an aggregate function, it is indicated by an operation-type of AGGREGATE
FUNCTION. If this is the case, the cursor will be closed. If the cursor
is closed, subsequent attempts to use that cursor without first doing
an OPEN for it, receive an SQLCODE-501. If the statement was a cursor-controlled
OPEN, then the cursor will remain closed.

User response
 Examine the expression which prompted the warning
to see if the cause of the problem can be determined. The problem
might be data-dependent, in which case you must examine the data that
was being processed at the time the error occurred. 
 If the
arithmetic expression in error was within the SELECT list of the outer
SELECT statement, then you should include an indicator variable for
all expressions in the SELECT list. This allows processing to continue
so that non-error column and expression values can be returned.
 See
the explanation of SQLCODE -405 for allowed ranges of numeric data
types.

SQLSTATE:
   22502