Flashback Pluggable Database Level in Oracle Multitenant Architecture 12cR2 (12.2.0.1)

First, the case of UNDO tablespace:

In Oracle 12cR1 the undo tablespace was common and shared between all container databases, so features like flashback was only feasible on the container-level.

In 12cR2 this is changed as you create a local undo tablespace.

By executing the following query:

SQL> SELECT con_id, tablespace_name

FROM   cdb_tablespaces

WHERE  tablespace_name LIKE ‘UNDO%’

ORDER BY con_id;

 

Only the root container has UNDO tablespace

 

pic1

An existing pluggable database with no local undo tablespace

pic2

To enable Local Undo Tablespace:

Access the database as sysdba to the root container CBD$ROOT

SQL>shutdown immediate;

SQL> startup upgrade;

SQL> alter database local undo on;

SQL> shutdown immediate;

SQL>startup;

To check that its successful, execute the following query:

SQL>set pages 1000

SQL>set lines 300

SQL> SELECT property_name, property_value

FROM   database_properties

WHERE  property_name = ‘LOCAL_UNDO_ENABLED’;

pic3

pic4

To Enable Flash Back:

 

Configure flash recovery area:

 

SQL> alter system set db_recovery_file_dest = ‘C:\app\emodb\oradata\oraclehero\fast_recover_area\’ scope=both;

 

SQL> archive log list;

pic5

 

SQL>  alter system set db_flashback_retention_target = 2880 scope = both;

 

**retention specified will be for 2 days 2880 minutes

Second, Enable flashback from CDB$root level:

SQL> alter database flashback on;

 

If you try to enable flashback from pluggable database level you will receive the following error:

 

SQL> alter session set container=PDB_EXPLORE;

 

SQL> alter database flashback on;

alter database flashback on

*

ERROR at line 1:

ORA-03001: unimplemented feature

Important remark: it’s important to enable force logging on the pluggable database level:

SQL> select pdb_name, force_logging, force_nologging from cdb_pdbs where pdb_name=’PDB_EXPLORE’;

pic6

To enable it:

 

SQL> alter session set container=PDB_EXPLORE;

SQL> alter pluggable database pdb_explore enable force logging;

 

pic7

Also, check that tablespaces are configured for flash back for pluggable database PDB_EXPLORE:

select name,flashback_on from v$tablespace;

pic8

Now to explore recover we can do it from different perspectives:

  • SCN
  • Specific date
  • Recovery point

 

SQL> Select dbms_flashback.get_system_change_number from dual;

 

GET_SYSTEM_CHANGE_NUMBER

————————

13524572

 

SQL> select to_char (sysdate, ‘mm-dd-yyyy hh24: mi: ss’) cdate from dual;

 

CDATE

———————

05-12-2017 12: 53: 35

 

SQL> create restore point test_flash guarantee flashback database;

 

 

Now to explore it, current Table called CITIES has the current data:

 

pic9

*** insert new records in the table:

INSERT INTO “EXP_SCHEMA”.”CITIES” (CITY_NAME, COUNTRY_NAME, TOURISM_LEVEL) VALUES (‘ BARCELONA’, ‘SPAIN’, ‘8’);

INSERT INTO “EXP_SCHEMA”.”CITIES” (CITY_NAME, COUNTRY_NAME, TOURISM_LEVEL) VALUES (‘ BERLIN’, ‘GERMANY’, ‘7’);

INSERT INTO “EXP_SCHEMA”.”CITIES” (CITY_NAME, COUNTRY_NAME, TOURISM_LEVEL) VALUES (‘TOKYO’, ‘JAPAN’, ‘6’);

Commit;

 

pic10

pic11

 

SQL> alter pluggable database pdb_explore close;

 

SQL> flashback pluggable database PDB_EXPLORE to restore point test_flash;

 

 

SQL> alter pluggable database pdb_explore open resetlogs;

 

 

Now check the table data again , its back as it was !!!

pic12

 

TDE (Transparent Data Encryption) Tablespace Live Conversion in Oracle 12cR2

One of the new exciting new security features in Oracle 12cR2 (12.2.0.1) , is the ability to encrypt your tablespaces “online“. In the past Implementing TDE required creating a new encrypted tablespace and then moving the data from the original tablespace to the encrypted tablespace (export/import data pump operations), which means a down time of your systems unless you use active data guard which minimizes TDE conversion implementation.

Let us now explore and simulate:

Current environment is: Oracle 12cR2 (Container Database Architecture) in Windows OS

Current ORACLE_HOME=C:\app\emodb\product\12.2.0\dbhome_2

Create a directory for the key store:

C:\app\emodb\product\12.2.0\dbhome_2\key_store

Go to sqlnet.ora file and add the below lines:

ENCRYPTION_WALLET_LOCATION=

(SOURCE=

(METHOD=file)

(METHOD_DATA=

(DIRECTORY=C:\app\emodb\product\12.2.0\dbhome_2\key_store)))

Set your COMPATIBLE Initialization parameter file to 12.2.0.0 :

SQL> ALTER SYSTEM SET COMPATIBLE = ‘12.2.0.0’ SCOPE = SPFILE;

Then execute:

SQL> ADMINISTER KEY MANAGEMENT CREATE KEYSTORE ‘C:\app\emodb\product\12.2.0\dbhome_2\key_store’ IDENTIFIED BY super_mario$88;

 

create keystore

ewallet will be created:

 

eWallet

Open the key store by executing:

SQL> ADMINISTER KEY MANAGEMENT SET KEYSTORE OPEN IDENTIFIED BY super_mario$88;

 

adminster key management

 

Now I will create the Master Key:

SQL> ADMINISTER KEY MANAGEMENT SET ENCRYPTION KEY IDENTIFIED BY super_mario$88 WITH BACKUP USING ‘mario_bck7’;

 

encryption key pass

Backup of key store generated (it’s better to place it in a different directory)

ewallet_backup

I have already created and activated a master key in the root container and, one in each of the pluggable databases. Now I will create local master key for pluggable database

 

SQL>alter session set container=PDBORCL;

 

SQL>ADMINISTER KEY MANAGEMENT SET KEYSTORE OPEN IDENTIFIED BY super_mario$88;

SQL>ADMINISTER KEY MANAGEMENT SET KEY IDENTIFIED BY super_mario$88 WITH BACKUP;

Now the interesting part…..the online tablespace conversion:

I will run the alter tablespace command to encrypt an existing tablespace named “COMPANY_INFO_TS”:

 

SQL>ALTER TABLESPACE COMPANY_INFO_TS  ENCRYPTION ONLINE USING ‘AES256’ ENCRYPT FILE_NAME_CONVERT = (‘COMPANY_INFO.DBF’, ‘COMPANY_INFO_ENC.DBF’);

tablespace conversion command

If you don’t specify the encryption algorithm, the default encryption will be AES128

Encrypted new data file is generated:

encrypted dbf file

 

of course you need to increase the tablespace size before your start the conversion, as the conversion process will require more space allocation.

You can use DataWalker for Oracle to test viewing the data file blocks that is not encrypted, and encrypted one:

http://www.toolswatch.org/2014/03/new-tool-datawalker-for-oracle-v1-0-in-the-wild/

 

Useful queries:

** to check wallet status

SELECT * FROM v$encryption_wallet;

** to check encryption keys created 1 in CDB and the other in PDB database:

SELECT con_id, key_id FROM v$encryption_keys;

 

ORA-30373: Object Data Types Are Not Supported In This Context , when creating Materialized View

If you face this error while creating materialized view:

 

ORA-30373: Object Data Types Are Not Supported In This Context

This means you are trying to create a Materialized View that references columns data types such as XMLTYPE or SDO_GEOMETRY or ESRI ST_GEOMETRY. This is a 12c limitation.

On the other hand, if you try to crate a materialized view with ST_GEOMETRY column this won’t be allowed.The workaround is not including the ST_GEOMETRY attribute in the materialized view.

 

Oracle Spatial Error ORA-29532: Java call terminated by uncaught Java exception ORA-06512: at “MDSYS.SDO_UTIL”, line 196

This error is received in 11g release, but fixed in 12c release :

 

ORA-29532: Java call terminated by uncaught Java exception: java.lang.RuntimeException
ORA-06512: at “MDSYS.SDO_UTIL”, line 196

is there any workaround for this problem in 11g …. YES:

1. Drop the spatial index on the geometry table
2. Run the update
3. Rebuild the spatial index

 

sqlplus error ORA-12560

This could be known and primitive to many people, however i am putting it to help the community in general from different technical-levels.

when you initiate sqlplus and trying to connect to your database instance you face the following error:

ORA-12560: TNS:protocol adapter error

 

if you are using windows OS, you need to check the following:

  1. check that the database services is up and running, go to the search icon and search for “services” and ensure all Oracle services are up and running.
  2.   if Oracle database is up and running fine, then check your environment variables in  CMD, you need to set the following:

 

set ORACLE_HOME=D:\app\db33\product\12.1.0\dbhome_33

set ORACLE_SID= ORACLE33

set PATH=D:\app\db33\product\12.1.0\dbhome_33\bin

to check that its reflected, execute the following to verify the value of ORACLE_HOME:

echo %ORACLE_HOME%

windows cmd oracle environment variables

now try initiating sqlplus and it will be working 🙂

 

 

INHERIT PRIVILEGES in Oracle 12c

Before Oracle 12c release, an Invoker Rights  unit always ran with the privileges of its invoker. If its invoker had higher privileges than its owner (for example, SYS, SYSTEM, or account with DBA role) then the IR unit might perform operations unintended by, or not authorized by the owner.

To explore first the behavior of invoker rights in 11g release, I have performed the following simulation test:

Oracle Database Release: 11.2.0.4.161018

Created a new user called “developer” with limited privileges:

CREATE USER developer

IDENTIFIED BY dodo_983

DEFAULT TABLESPACE TS_USER_DATA_01

TEMPORARY TABLESPACE TS_TEMP_DATA_01

PROFILE DEFAULT

ACCOUNT UNLOCK;

grant create session to developer ;

grant create procedure to developer ;

then the account will create a procedure:

CREATE OR REPLACE PROCEDURE priv_up  AUTHID CURRENT_USER AS

PRAGMA AUTONOMOUS_TRANSACTION;

BEGIN

EXECUTE IMMEDIATE ‘GRANT DBA TO developer’;

EXCEPTION

WHEN OTHERS THEN

NULL;

END;

/

Now the developer asks the DBA to execute multiple procedures under the schema (to trick him):

As SYS account you execute the SQL statement:

SQL> execute developer.priv_up();

 

11g-sys

 

And developer account now has DBA role !!!

Now this is a big security problem and its called “Privilege Escalation” …if your are a DBA and dealt with many third party applications, many of them provide *.sql scripts (tens of them sometimes) and you don’t have the time to inspect all sql code, this very difficult and hectic job.

 

In 12c This has been changed Invoker Rights unit can run with the privileges of its invoker only if its owner has either the INHERIT PRIVILEGES privilege on the invoker or the INHERIT ANY PRIVILEGES privilege.

A new account “developer” with the following definition:

CREATE USER developer

IDENTIFIED BY dodo_983

DEFAULT TABLESPACE TS_USER_DATA_01

TEMPORARY TABLESPACE TS_TEMP_DATA_01

PROFILE DEFAULT

ACCOUNT UNLOCK;

 

grant create session to developer ;

grant create procedure to developer ;

 

Now the developer creates a new function and a procedure (that has embedded SQL statement for granting):

 

CREATE OR REPLACE PROCEDURE priv_up  AUTHID CURRENT_USER AS

PRAGMA AUTONOMOUS_TRANSACTION;

BEGIN

EXECUTE IMMEDIATE ‘GRANT DBA TO developer’;

EXCEPTION

WHEN OTHERS THEN

NULL;

END;

/

A new account “super_user” with the following definition:

 

CREATE USER super_user

IDENTIFIED BY roro_983

DEFAULT TABLESPACE TS_USER_DATA_01

TEMPORARY TABLESPACE TS_TEMP_DATA_01

PROFILE DEFAULT

ACCOUNT UNLOCK;

 

grant create session to super_user ;

 

grant dba to super_user ;

 

SELECT grantee FROM   dba_role_privs WHERE  granted_role = ‘DBA’ ORDER BY grantee ;

 

users-with-dba

 

Connecting now as “superuser” account:

 

The powerful account “super_user” was tricked to execute the procedure:

SQL> execute developer.priv_up();

Now “developer” account has the “DBA” role!!!!

 

developer-dba-role

 

To remediate this:

 

SQL> REVOKE INHERIT PRIVILEGES ON USER super_user FROM PUBLIC;

 

revoke-inherit-privileges-from-public

 

Now if the super user tries to execute the procedure he will receive the below error:

 

ora06598

 

So, the procedure called by super_user wants to exercise one of super_user account privileges that the creator of the procedure (developer user) lacks.

Important Remark: executing the same procedure using “SYS” or “SYSTEM” accounts will by default lead to the same error ORA-06598 which is great since it will protect the SYS account from executing undesired (untrusted) SQL code.

its worth mentioning also, that if you try perform export data pump backup for schema  using SYS user after revoking INHERIT PRIVILEGE from all accounts from public, you will receive in the export log the below error:

ORA-06598: insufficient INHERIT PRIVILEGES privilege

To fix this export error:

SQL> GRANT INHERIT PRIVILEGES ON USER  SYS TO schema_Account;

 

This is a very nice security enhancement in 12c …..Thank You Oracle 🙂

Oracle Enterprise Manager 13c Error ORA-06512: at “SYSMAN.EM_TARGET”, line 9634

while installing Oracle Enterprise Manager 13c Cloud Control  i have faced the below errors:

ORA-01722: invalid number

ORA-06512: at “SYSMAN.EM_TARGET”, line 9634

ORA-06512: at “SYSMAN.EM_TARGET”, line 10403

ORA-06512: at “SYSMAN.EM_SYSTEM”, line 324

ORA-06512: at “SYSMAN.EM_SYSTEM”, line 242

ORA-06512: at “SYSMAN.MGMT_SYSTEM”, line 32

ORA-06512: at “SYSMAN.CFW_LIFECYCLE”, line 90

ORA-06512: at “SYSMAN.CFW_SERVICE_FAMILY”, line 58

ORA-06512: at line 15

 

To resolve this:

Set the following parameter:

 

SQL> alter system set optimizer_mode=all_rows scope=both;

 

Cheers ! 🙂