Temporary tablespace in Oracle RAC

Usually when I design Oracle users choose to create a separate table space and temporary table space for the user, such as:

SQL> create tablespace sales_tbs datafile '/home/oracle/dbfile/cdb/pdb1/sales_tbs01.dbf' size 10m;

SQL> create temporary tablespace sales_tmp tempfile '/home/oracle/dbfile/cdb/pdb1/sales_tmp01.dbf' size 10m

SQL> create user sales identified by sales default tablespace sales_tbs temporary tablespace sales_tmp;

But I never considered changes in the user's temporary table space under the RAC. 

In RAC temporary table space shared between all instances, the number of instances should be created and as many temporary files. 

If we use the 2-node RAC, temporary table space is preferably provided as two temporary data files. 

If you are using 4-node RAC, temporary table space is preferably set to four temporary data files. 

Doing so can reduce the file header lock contention.

You can increase the temporary table space for temporary files by following methods to meet the needs of RAC under, of course, this is not a hard requirement.

SQL> alter tablespace temp add tempfile '/home/oracle/dbfile/cdb/pdb1/pdb1_temp02.dbf' size 20m;

SQL> alter tablespace sales_tmp add tempfile '/home/oracle/dbfile/cdb/pdb1/sales_tmp02.dbf' size 10m;

SQL> select tablespace_name, file_name, bytes / 1024/1024 mb from dba_temp_files;

TABLESPACE_NAME              FILE_NAME              MB

------------------------------ -------------------- -----

TEMP      /home/oracle/dbfile/cdb/pdb1/pdb1_temp02.dbf  20

TEMP      /home/oracle/dbfile/cdb/pdb1/pdb1_temp01.dbf  20

SALES_TMP /home/oracle/dbfile/cdb/pdb1/sales_tmp02.dbf  10

SALES_TMP /home/oracle/dbfile/cdb/pdb1/sales_tmp01.dbf  10