what does "total length columns imprisonment too long" error meant informix?

i sum length columns imprisonment too long. erro following

sql] unsuccessful execute:   emanate list gtw_workflow_mon ( workflow_name varchar(255) not
null, workflow_loaded numeric(20) null, activity_name varchar(255) null, flags    
integer null, monitor_name varchar(255) null, classname varchar(255) null, s

tr0 varchar(255), str1 varchar(255), str2 varchar(255), num0 varchar(255), num1 
varchar(255), num2 varchar(255), date0 varchar(255), date1 varchar(255), date2 
varchar(255), primary pivotal (workflow_name,workflow_loaded,activity_name,monitor_name) )

  [sql] java.sql.sqlexception: sum length columns imprisonment too long.