Temporary tablespaces are created automatically by Oracle to store temporary data generated by user sessions. These temporary tablespaces are used to store data that is needed for the duration of a user session, such as intermediate results of queries or data that is being processed by a stored procedure. Temporary tablespaces are also used to store data that is generated by Oracle itself, such as data that is needed for sorting or hashing operations.
It is important to monitor the free space in temporary tablespaces to ensure that there is enough space to store all of the data that is needed by user sessions and Oracle itself. If a temporary tablespace runs out of space, then Oracle will be unable to store new data in the temporary tablespace, which can lead to errors and performance problems.