How to add supplemental logging on a table

alter table scott.emp 
add supplemental log group gg_feed (feed_id) always;

To reverse:

alter table scott.emp
drop supplemental log group gg_feed;

What is the meaning of the "10G 11G 12C" value in DBA_USERS.PASSWORD_VERSIONS?

Since I wrote my post What is the meaning of the "10G 11G" value in DBA_USERS.PASSWORD_VERSIONS?, Oracle 12c added yet another value to this column.

It's now common to see the string

PASSWORD_VERSIONS
10G 11G 12C

when you query the password_versions column of dba_users view.

What does it mean?

It's a list of password versions that was generated at the time the account was created.
This list will look a little different depending on your setting of the parameter SQLNET.ALLOWED_LOGON_VERSION_SERVER in your $TNS_ADMIN/sqlnet.ora at the time of account creation.

Oracle explains:

"The PASSWORD_VERSIONS column shows the list of password versions that exist for the account. 10G refers to the earlier case-insensitive Oracle password DES-based version, 11G refers to the SHA-1 version, and 12C refers to the SHA-2-based SHA-512 version."


In my 12.2 database, I have set the following parameter in my $TNS_ADMIN/sqlnet.ora file:

SQLNET.ALLOWED_LOGON_VERSION_SERVER=11

to allow older clients to connect.

When I then create a user with the CREATE USER statement, it will automatically generate all three password versions. Since my SQLNET.ALLOWED_LOGON_VERSION_SERVER was set to 11 at the time of creation, my password will indeed by case-sensitive, since case sensitive password was introduced in version 11.1 of the Oracle software.

If I adjust the parameter sqlnet.ora parameter:

SQLNET.ALLOWED_LOGON_VERSION_SERVER=12

and drop/recreate the user, my password version will have changed:

PASSWORD_VERSIONS
11G 12C

The setting of SQLNET.ALLOWED_LOGON_VERSION have the following effects:

SQLNET.ALLOWED_LOGON_VERSION_SERVER=11 will keep generating 10G, 11G and 12c password versions
SQLNET.ALLOWED_LOGON_VERSION_SERVER=12 will generate both 11G and 12C password versions, and also remove the 10G password version.
SQLNET.ALLOWED_LOGON_VERSION_SERVER=12a will generate only 12c password versions

Oracle call these three settings Greatest level of compatibility, Medium level of security, and Highest level of security, respectivly.

If you for some reason want the old-school case-insensitive password versions to apply, set your SQLNET.ALLOWED_LOGON_VERSION_SERVER to 10 or lower, and make sure the parameter sec_case_sensitive_logon is set to FALSE.

Any user created after setting SQLNET.ALLOWED_LOGON_VERSION_SERVER to 10 or lower, will be able to logon using case-insensitive passwords.

How to list all schemas and their sizes

If you want a list of schema sizes, join dba_segments with dba_users to limit the extract to users that are non-oracle maintained:

set lines 200
col owner  format a30
col "GB" format 999999
SELECT s.owner,sum(s.bytes/1024/1024/1024) "GB"
FROM dba_segments s join dba_users u
on (s.owner = u.username)
where u.oracle_maintained = 'N'
group by owner
ORDER BY 2 desc;

Example output

OWNER                               GB
------------------------------ -------
USER1                            19577
USER2                             6144
USER3                             2306

How to work around ORA-38338: incorrect ILM policy scope for row-level ADO policies

When adding an ADO policy on a table, like this:

CREATE TABLE TEST_TABLE1
(
  col1 NUMBER(38),
  col2 NUMBER(38),
  col3 DATE
)
NOCOMPRESS 
TABLESPACE USERS
ILM ADD POLICY ROW STORE COMPRESS ADVANCED 
ROW AFTER 1 DAY OF NO ACCESS;

oracle returned

ORA-38338: incorrect ILM policy scope

This policy is not valid for row-level ADO policy. The only valid option is

ILM ADD POLICY ROW STORE COMPRESS ADVANCED 
ROW AFTER X DAY OF NO MODIFICATION;

How to deinstall an old oracle installation using oui

You can use the following command to remove an obsolete oracle software installation from the central inventory:

$ORACLE_HOME/oui/bin/runInstaller -silent -deinstall REMOVE_HOMES={"/u01/oracle/product/11204"}

Remember to clean out the physical files with an appropriate operating system command.

The above method is an alternative to the method outlined in this post.

Parameters that can be removed after upgrade to 12.2

From Information For Parameters _upgrade_optim and _upgrade_capture_noops (Doc ID 2182783.1):


Below parameters gets added after upgrade to 12.2:

_upgrade_optim = FALSE
_upgrade_capture_noops = FALSE

These parameters are part of upgrade optimizations. They do not have any effect on upgrade currently.

Since these parameters does not have any impact, it can be removed safely after upgrade to 12.2.


Can be removed, like this:

echo "alter system reset \"_upgrade_optim\" scope=spfile SID='*';" | sqlplus / as sysdba
echo "alter system reset \"_upgrade_capture_noops\" scope=spfile SID='*';" | sqlplus / as sysdba

How to load a plan from the AWR into the SMB

To load a plan found in an AWR snapshot into the SMB, you need to add it to an STS first, then load it into the SMB.
Here is how:

1. create an empty STS:

exec dbms_sqltune.create_sqlset(sqlset_name=>'mysts');

2. Note the snapshots where your plan was recorded, and add the plans to your STS:

DECLARE
  my_cur  dbms_sqltune.sqlset_cursor;
BEGIN
  OPEN my_cur FOR
     SELECT VALUE(x)
     FROM   TABLE( dbms_sqltune.select_workload_repository(begin_snap=>5840, 
                                                           end_snap=>5841, 
                                                           basic_filter=>'sql_id = ''45wmakdh9ak9s''')) x;

     dbms_sqltune.load_sqlset(sqlset_name => 'mysts', populate_cursor => my_cur);
END;
/

You can now check your STS for its contents:

select sqlset_name,
     sql_id,
     plan_timestamp,
     parsing_schema_name "schema",
     plan_hash_value,round(elapsed_time/1000000) "duration in seconds",
     cpu_time,
     buffer_gets,
     disk_reads,
     executions
from   dba_sqlset_statements
where  sqlset_name = 'mysts'
;

SQLSET_NAME	SQL_ID	PLAN_TIMESTAMP	schema	PLAN_HASH_VALUE	duration in seconds	CPU_TIME	BUFFER_GETS	DISK_READS	EXECUTIONS
mysts	45wmakdh9ak9s	11.09.2018 15:22:13	SH	3827183161	0	0	0	0	0
mysts	45wmakdh9ak9s	06.09.2018 16:45:26	SH	4026264003	579	85550842	24062750	101808	3278857

We can see from the output that there are actually two different plans in the STS now, one with plan_hash_value=3827183161 and another one with plan_hash_value=4026264003.

In my case I wanted only the one with plan_hash_value=3827183161.

3. Finallly, load the contents of your STS into your SMB:

VARIABLE cnt NUMBER
EXECUTE :cnt := DBMS_SPM.LOAD_PLANS_FROM_SQLSET( -
                    sqlset_name=>'mysts', basic_filter=>'plan_hash_value=3827183161', sqlset_owner=>'SYS');

print :cnt;