Spool space issue - response (3) by M.Saeed Khurram

HI,
If you are talking about the sequence of joins execution, Teradata optmizer decides how to and in which sequence process the joins. 
In order to avoid spool space problem you can check and move any drived tables to Volatile tables. 
Also check that the appropriate spool is assigned to the user. Collect only those stats which are required.