A tempfile is a file that is part of an Oracle database. Tempfiles are used with TEMPORARY TABLESPACES and are used for storing temporary data like sort spill-over or data for global temporary tables.
 Using tempfiles
To see what tempfiles are used:
SELECT * FROM dba_temp_files;
Create a tablespace with TEMPFILE:
CREATE TEMPORARY TABLESPACE temp1 TEMPFILE '/u01/oradata/orcl_temp1_01.dbf' SIZE 100M;
Remove a tempfile from the database:
ALTER DATABASE TEMPFILE '/u01/oradata/orcl_temp1_01.dbf' DROP;