ORA-1652: unable to extend temp segment by 21446 in tablespace SYSTEM

ORA-1652: unable to extend temp segment by 21446 in tablespace SYSTEM 

ORA-1652: unable to extend temp segment by 21446 in tablespace SYSTEM reported in the alert.log.

This occurs when Users have the SYSTEM tablespace assigned as their default temporary tablespace.

The following query displays the default tablespace of all the users

SQL> SELECT USERNAME, DEFAULT_TABLESPACE, TEMPORARY_TABLESPACE FROM DBA_USERS; 

change the default temporary tablespace for users who have the SYSTEM tablespace assigned as their default temporary tablespace to use TEMP tablespace instead. 

SQL> ALTER USER username TEMPORARY TABLESPACE TEMP;