Immediate materialized view definition cannot contain a SUM function over a nullable expression

Error constant SQLE_UPDATABLE_MATVIEW_SUM_NULL_EXPR
ODBC 2 State ERROR
ODBC 3 State ERROR
Severity 15
SQLCODE –1286
SQLSTATE 42WCD
Sybase error code 13668
Probable cause

You attempted to change the refresh type to immediate for a materialized view whose definition contains a SUM function over a nullable expression.