Sizing Spool Space
Spool space, which is a form of temporary space, is frequently overlooked in capacity planning, yet it is critical to the operations of the database. Spool space needs vary from table to table, user to user, application to application, and with frequency of use. Very large systems use even more spool than smaller systems. Unlike all other row types, spool file rows have a maximum length of approximately 1MB rather than 64KB.
Spool falls into these categories: