alter session set nls_date_format = 'Dy DD-Mon-YYYY AD' ;
select sysdate, to_date('01-JAN-4712 BC','DD-MON-YYYY AD'), to_date('30-DEC-9999 AD','DD-MON-YYYY AD') from dual ;

Without encountering this error:

ORA-01841: (full) year must be between -4713 and +9999, and not be 0
01841. 00000 – “(full) year must be between -4713 and +9999, and not be 0″
*Cause: Illegal year entered
*Action: Input year in the specified range

But for processes running from cron, I found I had to additionally make the below changes (this is on old version: 32 bit Linux 2.4.21-27.ELsmp Red Hat Enterprise Linux AS release 3 (Taroon Update 4) – maybe not needed for newer versions).

vi /etc/init.d/crond

Add lines like:

ulimit -Hu 131072  # new line Jul 2011
ulimit -Su 131072  # new line Jul 2011
ulimit -Hn 262144  # new line Jul 2011
ulimit -Sn 262144  # new line Jul 2011

These should be the first commands in that file.

Restart cron with:

/etc/init.d/crond restart

Not relevant for cron, but file /etc/profile is loaded at login and may have been edited to contain ulimit settings – if so those lines would need changed or removed for normal (non cron) logins.

Thanks to Michael Heiming for this.

SQL> select password from dba_users where username = 'MYUSER';

PASSWORD
------------------------------
086FAA387C794B46

SQL> alter user MYUSER identified by mypassword ;

User altered.

SQL> conn MYUSER/mypassword
Connected.
SQL> alter user MYUSER identified by values '086FAA387C794B46';

User altered.

SQL> sho user
USER is "MYUSER"

The above works for versions up to 10g. For 11g, instead use:

SQL> set long 9999
SQL> select dbms_metadata.get_ddl ('USER', 'MYUSER') from dual ;

Source: Laurent Schneider.

SQL> alter system set pga_aggregate_target=1g comment='Andrew Fraser 13-May-2010 was 390m'  scope=spfile sid='*' ;

alter session set nls_date_format='Dy DD-Mon-YYYY HH24:MI:SS';

Then in Oracle SQL Developer, right click on the table or object in question, select ‘open‘, and look at the ‘details‘ tab.

Or alternatively still in SQL, look at the created column:

select object_name, created from user_objects order by 2;

That is for objects owned by you. For objects owned by others:

select object_name, created from all_objects order by 2;

Note that the column ‘last_ddl_time’ is not as useful as it sounds, since even operations like GRANTs on the table update the ‘last_ddl_time’.