Date formatting in PostgreSQL

select action_type, to_char(action_date,'DD Mon YYYY'), count(*) from actions group by action_type,

action_type     |   to_char   | count
-----------------+-------------+-------
 action1 | 27 Oct 2020 | 47831
 action1 | 22 Oct 2020 |   640
 action1 | 20 Oct 2020 |     1
 action1 | 22 Oct 2020 |  1654
 action1 | 26 Oct 2020 |   290
 action2 | 21 Oct 2020 |     8
 action2 | 27 Oct 2020 |   140
 action2 | 26 Oct 2020 |   900

Documentation here

How to change the control_files parameter used in the spfile

Mind your syntax when you are changing certain multi-value parameters directly in the spfile. Oracle will tell you that the syntax is accepted, but it will give you an error later. The following example is from an attempt to change the control_files parameter.

Won't work:

SQL> alter system set control_files='/oradata/proddb01/control01.ctl, /fra/proddb01/control02.ctl' scope=spfile;

System altered.

During mount stage, this will give you the following message in the database's alert log:

ORA-205 signalled during: ALTER DATABASE   MOUNT...
ORA-00202: control file: /oradata/proddb01/control01.ctl, /fra/proddb01/control02.ctl
ORA-27037: cannot obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 7

Works:

SQL> alter system set control_files='/oradata/proddb01/control01.ctl','/fra/proddb01/control02.ctl' scope=spfile;

System altered.

You should enclose both values within ' ' apostroph characters.