Investigating phantom and leftover spool issues
Spool space is the total amount of space on the system that has not been allocated. The primary reason for the spool space is to store intermediate results or queries that are being processed in Teradata. For example, when executing a conditional query all the qualifying rows that satisfy the given conditions will be stored in the spool space for further processing by the query. Any permanent space on the system that is currently unassigned is available as spool space for the queries.
Each user on the system is assigned certain spool space to complete and execute queries. Spool space can be assigned to users individually or can be enforced by the profile.
An intermediate spool is created while executing queries are released by the system automatically once the step is completed, and in the case of volatile tables it is released once the session is disconnected.
Sometimes, these work tables are not dropped and the spool is not released.
