Query to check High Watermark in Datafiles

 set verify off

column file_name format a50 word_wrapped

column smallest format 999,990 heading "Smallest|Size|Poss."

column currsize format 999,990 heading "Current|Size"

column savings  format 999,990 heading "Poss.|Savings"

break on report

compute sum of savings on report

column value new_val blksize

select value from v$parameter where name = 'db_block_size';

/

select file_name,

       ceil( (nvl(hwm,1)*&&blksize)/1024/1024 ) smallest,

       ceil( blocks*&&blksize/1024/1024) currsize,

       ceil( blocks*&&blksize/1024/1024) -

       ceil( (nvl(hwm,1)*&&blksize)/1024/1024 ) savings

from dba_data_files a,

     ( select file_id, max(block_id+blocks-1) hwm

         from dba_extents

        group by file_id ) b

where a.file_id = b.file_id(+) order by savings desc

/

Query to check blocking sessions in Oracle database

 Query to check blocking sessions in Oracle database from v$lock:

SELECT DECODE(request,0,'Holder: ','Waiter: ') || sid sess,
  id1,
  id2,
  lmode,
  request,
  type
FROM v$lock
WHERE (id1, id2, type) IN
  (SELECT id1, id2, type FROM v$lock WHERE request > 0
  )
ORDER BY id1,
  request;

Script to check free space and used space in Oracle Database tablespaces

select a.tablespace_name,
       a.bytes_alloc/(1024*1024) "TOTAL ALLOC (MB)",
 a.physical_bytes/(1024*1024) "TOTAL PHYS ALLOC (MB)",
       nvl(b.tot_used,0)/(1024*1024) "USED (MB)",
       (nvl(b.tot_used,0)/a.bytes_alloc)*100 "% USED"
from ( select tablespace_name,
       sum(bytes) physical_bytes,
sum(decode(autoextensible,'NO',bytes,'YES',maxbytes)) bytes_alloc
       from dba_data_files
       group by tablespace_name ) a,
     ( select tablespace_name, sum(bytes) tot_used
       from dba_segments
group by tablespace_name ) b
where a.tablespace_name = b.tablespace_name (+)
--and   (nvl(b.tot_used,0)/a.bytes_alloc)*100 > 10
and   a.tablespace_name not in (select distinct tablespace_name from dba_temp_files)
and   a.tablespace_name not like 'UNDO%'
order by 1
 --order by 5
/ 

RMAN-03009: failure of allocate command on ORA_AUX_SBT_TAPE_1 channel

This is an error during Database Clone using RMAN. I was trying to restore database using RMAN Backup 

RMAN-00571: ===========================================================

RMAN-00569: ===============
ERROR MESSAGE STACK FOLLOWS ===============

RMAN-00571: ===========================================================

RMAN-03002: failure of Duplicate Db command
RMAN-05501: aborting duplication of target database

RMAN-03009: failure of allocate command on ORA_AUX_SBT_TAPE_1 channel 
ORA-19554: error allocating device, device type: SBT_TAPE, device name:

ORA-27211: Failed to load Media Management Library

Additional information: 

Cause: Backup Configuration was modified.

Solution:
Use the below command to Resolve the error and continue with Database Restore

rman auxiliary / 
run
{
allocate auxiliary channel c1 type disk;
allocate auxiliary channel c2 type disk;
duplicate database to 'DEV' backup location '/Daily_Backup/Backup_16042018';
}
exit;
EOF

How to add space in ACFS filesystem?

The below post explains the step-by-step process to add storage to a mountpoint in ACFS filesystem

1.Before extending the mountpoint storage we need to add an LVM of required Storage Capacity on the server.

For checking the LUN's available on the server, click here

For now, assume the LUN added is /dev/sdf1

2. As root User, check the available disks by running the below command

$ /usr/sbin/oracleasm listdisks
DATA01
OCR_VOTE01
OCR_VOTE02
OCR_VOTE03

3. Create a new disk using the below command

/usr/sbin/oracleasm createdisk DATA02 /dev/sdf1 

Where DATA02 is the name of new disk added
/dev/sdf1 is the LUN added for storage extension.

4. Verify the disk is added by running the below command.

 $/etc/init.d/oracleasm  listdisks
DATA01
DATA02
OCR_VOTE01
OCR_VOTE02
OCR_VOTE03

5. Navigate to the other cluster nodes and run the scandisks command to reflect the newly added disk on all the nodes of cluster.

$/etc/init.d/oracleasm  scandisks
Scanning the system for Oracle ASMLib disks:               [  OK  ]

 $/etc/init.d/oracleasm  listdisks
DATA01
DATA02
OCR_VOTE01
OCR_VOTE02
OCR_VOTE03

6. Now login to the database server as GRID user (Where ASM instance is running) to add space to ACFS.

Set the environment as required


export ORACLE_HOME=/u01/app/12.1.0/grid
export PATH=$PATH:$ORACLE_HOME/bin
export ORACLE_SID=+ASM1

$sqlplus / as sysasm

SQL> alter diskgroup DATA add disk '/dev/oracleasm/disks/DATA02';

Diskgroup altered.


7. Increase the space on filesystem

As root user,

$acfsutil size +1G /oradata
acfsutil size: new file system size: 591833071616 (564416MB)

How to Enable Database Vault in Oracle database Version 11gR1?

Steps to enable Database Vault in Oracle Database 11gR1:

1. In the command prompt, use DVCA utility to enable Oracle Database Vault.

e.g.

dvca -action enable 
  -oh /u01/app/oracle/product/11.1.0/db_1
  -service conn_alias 
  -instance orcl 
  -dbname orcl 
  -owner_account lbrown_dvowner 
  -logfile dvcalog.txt 

Enter SYS password: sys_password
Enter owner password: owner_password

Parameter Description:
======================

-service is the name of the database specifier. The specifier can be a connect descriptor or net service name. 

-instance is the name of the database instance.

-dbname is the database name.

-sys_passwd is the SYS password. If you use a cleartext password on the command line, you must include the nodecrypt option. If you omit the password, DVCA prompts you for it. Preferably, omit the password and then enter it interactively when prompted.

-owner_account is the Oracle Database Vault Owner account name.

-owner_passwd is the Oracle Database Vault Owner account password. If you use a cleartext password on the command line, you must include the nodecrypt option. If you omit the password, DVCA prompts you for it. Preferably, omit the password and then enter it interactively when prompted.

-logfile is an optional flag to specify a log file name and location. You can enter an absolute path, or enter a path that is relative to the location of the $ORACLE_HOME/bin directory.

-silent is the option to run in command line mode. This option is required if you are not running DVCA in an xterm window.

-nodecrypt is the option to read plaintext passwords.

-lockout is the flag to use to disable SYSDBA operating system authentication.

2. Stop the database, Database Control console process, and listener.

Enable the Oracle Database Vault option as follows:
 The make command enables both Oracle Database Vault (dv_on) and Oracle Label Security (lbac_on).
 You must enable Oracle Label Security before you can use Database Vault.

cd $ORACLE_HOME/rdbms/lib
make -f ins_rdbms.mk dv_on lbac_on

cd $ORACLE_HOME/bin
relink all

3.Restart the database, Database Control console process, and listener.

4. Verify Oracle Database Vault and Oracle Label Security are enabled.

SELECT * FROM V$OPTION WHERE PARAMETER = 'Oracle Label Security';

SELECT * FROM V$OPTION WHERE PARAMETER = 'Oracle Database Vault';

How to create directories in Oracle Database?

Database Directories are required to read/write to a filesystem location from plsql code.

Below is the syntax to create database directory

SQL> create directory PLSQL_DIR AS '/oratmp/code';

Directory created.

Grant Read/write privileges to Required Schema (e.g . APPS)

SQL> GRANT READ,WRITE ON DIRECTORY PLSQL_DIR TO APPS;

Grant succeeded.

How to use coe_xfr_sql_profile.sql to Improve performance of a sql query?

Oracle SQL Performance tuning is one of the frequently reported issues in a Oracle Database administrator's daily job.
Very often we notice that sql queries or concurrent Programs which were running within few minutes earlier are now taking hours to be completed.
Underlying reason is due to the plan_hash_value used by the query has been changed.
coe_xfr_sql_profile.sql is the script developed by Oracle Support which helps us to identify the plan_hash_value which will resolve the performance issue.

Steps to use the script coe_xfr_sql_profile.sql

1. Download the script to a temporary directory on the database server.
Script is also available in Oracle Metalink.

2. Before Running the coe_xfr_sql_profile.sql, we need to know the sql_id of the sql query which is taking longer time to complete than usual.

To find the sql_id use below query

2.1 If you know the database SID of the long running query.
select inst_id,sid,serial#,status,last_Call_et,sql_id from gv$session where sid= '&sessionid';

2.2 If you know the query test, Use gv$sql and gv$sqlarea views to get the sql_id.

3. Login to sqlplus as sysdba and run coe_xfr_sql_profile.sql at the SQL prompt.

$ sqlplus “/as sysdba”
SQL> @coe_xfr_sql_profile.sql
Parameter 1:
SQL_ID (required)

Enter value for 1: 0a3f7vuks8d7y   (--this is the sql_id of long running sql)
PLAN_HASH_VALUE AVG_ET_SECS
————— ———–
1484137450 15.6
3622468234 4560.76

[Output shows the list of available plan hash values, which can be forced on to the sql query. We need to select the plan_hash_value with low ETA to resolve the performance issue]

Parameter 2:
PLAN_HASH_VALUE (required)

Enter value for 2: 1484137450 


++Based on the inputs provided, it generates a sql script with naming convention coe_xfr_sql_profile_0a3f7vuks8d7y_1484137450.sql as output

coe_xfr_sql_profile_<sql_id>_<plan_hash_value>.sql

4. Run the script as sysdba

SQL>coe_xfr_sql_profile_0a3f7vuks8d7y_1484137450.sql 

5. Verify that Performance issue is resolved by Re-running the sql.

How to Resolve ACFS-03008 : The volume expansion limit has been reached?

Issue: ACFS Filesystem resize operation fails with "ACFS-03008: The volume could not be resized.  The volume expansion limit has been reached."

$acfsutil size +1G /oradata
acfsutil size: ACFS-03008: The volume could not be resized.  The volume expansion limit has been reached.
acfsutil size: ACFS-03216: The ADVM compatibility attribute for the diskgroup was below the required version (11.2.0.4.0) for unlimited volume expansions.

Analysis:

Compatible attribute for advm and rdbms is below the required version.

 SQL>  select group_number, name, value from v$asm_attribute where name like 'compatible%' ;

GROUP_NUMBER
------------
NAME
--------------------------------------------------------------------------------
VALUE
--------------------------------------------------------------------------------
           1
compatible.asm
12.1.0.0.0

           1
compatible.rdbms
11.2.0.0.0

           1
compatible.advm
11.2.0.0.0

           2
compatible.asm

12.1.0.0.0

           2
compatible.rdbms
10.1.0.0.0




Solution:

SQL> ALTER DISKGROUP DATA SET ATTRIBUTE 'compatible.advm'='11.2.0.4.0' ;

Diskgroup altered.

SQL>  ALTER DISKGROUP DATA SET ATTRIBUTE 'compatible.rdbms'='11.2.0.4.0' ;

Diskgroup altered.

Now verify the issue is resolved.
$ acfsutil size +10G /oradata
acfsutil size: new file system size: 603644231680 (575680MB)

ACFS-03171: Insufficient contiguous free ASM Diskgroup space

Issue:  

ACFS file resize operation operation fails with ACFS-03171: Insufficient contiguous free ASM Diskgroup space


[root@erptestdb01 ~]# cd /sbin
[root@erptestdb01 sbin]# acfsutil size +100M /oradata
acfsutil size: ACFS-03171: Insufficient contiguous free ASM Diskgroup space.  Check the ASM alert log.

Solution:

Increase size in smaller chunks until the required size is reached
[root@erptestdb01 bin]# acfsutil size +10M /oradata
acfsutil size: new file system size: 590625112064 (563264MB)

ORA-32771: Cannot Add File To Bigfile Tablespace

When trying to add a datafile to a tablespace , got the error – ORA-32771: cannot add file to bigfile tablespace.

SQL> ALTER TABLESPACE BIG_TBSP1 add datafile ‘+DATA/df01.dbf’ size 130G;
ALTER TABLESPACE BIG_TBSP1 add datafile ‘+DATA/df01.dbf’ size 130G;
*
ERROR at line 1:
ORA-32771: cannot add file to bigfile tablespace

SOLUTION:

A bigfile tablespace can contain only one datafile and no other datafile can be added to that.

SQL> select BIGFILE from dba_tablespaces where tablespace_name=’BIG_TBSP1’;

BIGFILE
———————– —
YES

How to increase space in Bigfile Tablespace?


BIGFILE tablespace stores its data in a single datafile with a much larger capacity.

We can resize the size of the datafile in BIGFILE tablespace using ALTER DATABASE Command


ALTER DATABASE DATAFILE '/+DATA/df0101.dbf' RESIZE 180G;

Since BIGFILE Tablespace has only one datafile, there is no need to identify the datafile and increase its size.
We can use ALTER TABLESPACE command to resize at the tablespace level.

ALTER TABLESPACE BIG_TBSP1 RESIZE 180G;

What is the difference between Switchover and Failover in Oracle Dataguard?

A switchover means just switching roles between the primary database and standby db.
nswitchover, the primary database chnaged to a standby role, and the standby database changed to the primary role.
This is typically done for planned maintenance of the primary db server.

A failover is when the primary database fails and one of the standby databases is 
transitioned to take over the primary role. Failover is performed only in the event 
of a catastrophic failure of the primary database, and there is no possibility of 
recovering the primary database in a timely manner. Failover may or may not result 
in data loss depending on the protection mode in effect at the time of the failover.

How to mirror database Privileges of a Oracle database user to another database user?

Script for Mirroring Privileges of a user:

Scenario: A Database schema named "TEST2" is created and business wants to grant the privileges for the user same as already existing Database user "TEST1".

Run the below queries as SYS or any Privileged user to get the DDL commands in Oracle for TEST1 user.

SELECT DBMS_METADATA.GET_GRANTED_DDL('ROLE_GRANT','TEST1') FROM DUAL;

 SELECT DBMS_METADATA.GET_GRANTED_DDL('SYSTEM_GRANT','TEST1') FROM DUAL;

 SELECT DBMS_METADATA.GET_GRANTED_DDL('OBJECT_GRANT','TEST1') FROM DUAL;


 The output will be a sequence of grant commands related to privileges assigned to TEST1 user. Now replace the string TEST1 with new user name "TEST2" and run the commands.

 This will grant all privileges same as TEST1 user to TEST2 user in Oracle Database.

Change Oracle Database to ArchiveLog Mode

Steps to change the database to Archivelog Mode:

1. Login to the database server. Connect to sqlplus as sysdba

$sqlplus / as sysdba

2. Shutdown the database

SQL> shutdown immediate

3. Take a full database Backup (Cold Backup in this case)

4. Startup the database in mount stage

SQL> startup mount

5. Enable Archivelog mode

SQL> alter database archivelog;

6. Open the Database.

SQL> Alter database open;

7. Verify the changes.

SQL> archive log list;

Enable ArchiveLog Mode on Oracle RAC database fails with ORA-00265

On a test RAC environment, while archiving is being enabled, "ALTER DATABASE ARCHIVELOG" command errored with ORA-00265: instance recovery required, cannot set ARCHIVELOG mode

Below are the steps performed to enable Archivelog mode on a 3-node RAC database environment.

test0115:TEST1011 $ srvctl status database -d TEST101
Instance TEST1011 is running on node test0115
Instance TEST1012 is running on node test0116
Instance TEST1013 is running on node test0117
test0115:TEST1011 $
test0115:TEST1011 $ srvctl stop database -d TEST101


test0115:TEST1011 $ srvctl status database -d TEST101
Instance TEST1011 is not running on node test0115
Instance TEST1012 is not running on node test0116
Instance TEST1013 is not running on node test0117
test0115:TEST1011 $


test0115:TEST1011 $ srvctl start database -d TEST101 -o mount
test0115:TEST1011 $  srvctl status database -d TEST101
Instance TEST1011 is running on node test0115
Instance TEST1012 is running on node test0116
Instance TEST1013 is running on node test0117
test0115:TEST1011 $


test0115:TEST1011 $ sqlplus / as sysdba

SQL*Plus: Release 11.2.0.4.0 Production on Sat May 9 14:13:54 2020

Copyright (c) 1982, 2013, Oracle.  All rights reserved.


Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, Real Application Clusters and Automatic Storage Management options

SQL> select name,open_mode from gv$database;

NAME      OPEN_MODE
--------- --------------------
TEST101   MOUNTED
TEST101   MOUNTED
TEST101   MOUNTED

SQL>SQL> alter database archivelog;
alter database archivelog
*
ERROR at line 1:
ORA-00265: instance recovery required, cannot set ARCHIVELOG mode

Solution:
=========

1. Shutdown the database cleanly

SQL> shutdown immediate (on 3 RAC nodes)

2. Startup the database in mount stage

SQL> startup mount

3. Enable Archivelog mode

SQL> Alter database archivelog;

Database altered.

4. Open the database

SQL> Alter database open.

5. Verify archielog mode is enabled.

SQL> ARCHIVE LOG LIST;

Impdp fails with error ORA-31604

Issue:

When tried to Import a table from one Oracle database to another using IMPDP utility,encountered the error ORA-31604: invalid transform NAME parameter "MODIFY" for object type PROCACT_INSTANCE in function ADD_TRANSFORM

Impdp logfile has the below error:

Starting "<LOGIN_SCHEMA>"."SYS_IMPORT_FULL_10":  <LOGIN>/******** parfile=<PARFILE_NAME>.par logfile=<LOG_NAME>.log dumpfile=<DUMPFILE_NAME>.dmp parallel=1

Processing object type TABLE_EXPORT/TABLE/PROCACT_INSTANCE

ORA-39126: Worker unexpected fatal error in KUPW$WORKER.LOAD_MD_TRANSFORMS []

ORA-31604: invalid transform NAME parameter "MODIFY" for object type PROCACT_INSTANCE in function ADD_TRANSFORM

ORA-06512: at "SYS.DBMS_SYS_ERROR", line 86

ORA-06512: at "SYS.KUPW$WORKER", line 8996

Cause: This is a bug in Oracle Database versio 11g, fixed in Oracle Database version 12c

Solution:

As a workaround, implement any of the below solutions:

1. Use an additional parameter that is exclude=PROCACT_INSTANCE during impdp

2. Redo the export with exclude=PROCACT_INSTANCE and perform import using new dumpfiles.

The use of the exclude=PROCACT_SYSTEM will exclude the resource manager objects such as resource plans and groups. We need to re-create resource plans and groups after impdp is successfully completed.

How to check if MRP Process is Running

Below Query is Used to verify if MRP process is running fine on Standby Database, after any maintenance activity that requires disconnect to Primary and Standby database.

SQL> SELECT CLIENT_PROCESS, PROCESS, THREAD#, SEQUENCE#, STATUS FROM V$MANAGED_STANDBY;

Below is the sample output from the query:

SQL> SELECT CLIENT_PROCESS, PROCESS, THREAD#, SEQUENCE#, STATUS FROM V$MANAGED_STANDBY;

CLIENT_P PROCESS      THREAD#  SEQUENCE# STATUS

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

ARCH     ARCH               2     101072 CLOSING

ARCH     ARCH               0          0 CONNECTED

ARCH     ARCH               1     298101 CLOSING

ARCH     ARCH               2     103073 CLOSING

ARCH     ARCH               3      95398 CLOSING

ARCH     ARCH               1     296100 CLOSING

ARCH     ARCH               3      95399 CLOSING

ARCH     ARCH               3      95400 CLOSING

ARCH     RFS                0          0 IDLE

ARCH     RFS                0          0 IDLE

ARCH     RFS                0          0 IDLE

LGWR     RFS                2     101074 IDLE

LGWR     RFS                1     296102 RECEIVING

UNKNOWN  RFS                0          0 IDLE

UNKNOWN  RFS                0          0 IDLE

LGWR     RFS                3      95401 IDLE

UNKNOWN  RFS                0          0 IDLE

17 rows selected.

Convert Physical database into a Snapshot Standby Database

What are the benefits of Snapshot standby database?

Snapshot Standby Database is introduced from Oracle 11gR1. A Snapshot Standby database is a physical standby that is temporarily disconnected from Data Guard configuration, and started in READ-WRITE mode.It functions as a updateable Stand-alone Database, which is an exact Replica of Primary Database which is normally used for testing purpose. We can revert the Snapshot standby database to Physical Standby database after the testing is completed.

Steps to convert Physical database into a Snapshot Standby Database:

1. First step to convert to Snapshot standby database is to enable FLASHBACK feature on the Physical Standby, if not already enabled.

Ensure there is sufficient space available in Flash Recovery Area (FRA) for Flashback Logs.

2. Stop redo apply on the physical standby database:

SQL>alter database recover managed standby database cancel;

3. Turn on flashback logging:

SQL>alter database flashback on;

4. Convert the standby database into a snapshot standby database:

( For RAC Configurations: Shutdown all other instances except one, which is used as Snapshot standby database)

SQL>alter database convert to snapshot standby;

5.Shut down the snapshot standby database and startup the database (it will be opened for read/write access):

SQL>shutdown immediate;

SQL>startup

After the Snapshot mode is enabled on the database, perform the required testing and revert back to Physical Standby mode after the testing is complete.

Steps to Revert the Physical Standby Database Back to its Original State

1. Change the standby database back into its standby mode (from snapshot mode) as follows:

SQL>startup mount force;

SQL>alter database convert to physical standby;

SQL>shutdown immediate;

SQL>startup nomount;

SQL>alter database mount standby database;

2. Enable redo log apply.

SQL>alter database recover managed standby database using current logfile disconnect;

3.On the primary database, issue the following statement to re-enable archiving to the physical standby database:

SQL>alter system set log_archive_dest_state_2=enable scope=both;

Protection Modes in Oracle Dataguard

We have 3 Protection modes available in Oracle DataGuard

1. Maximum Performance :

This is the default protection mode. It provides the highest level of data protection that is possible

without affecting the performance of a primary database. This is accomplished by allowing transactions to commit as soon as all redo data generated by those transactions has been written to the online log. 

2. Maximum Availability :

This protection mode provides the highest level of data protection that is possible without compromising the availability of a primary database. Transactions do not commit until all redo data needed to recover those transactions has been written to the online redo log and to at least one standby database.

3. Maximum Protection :

This protection mode ensures that no data loss will occur if the primary database fails. To provide this level of protection, the redo data needed to recover a transaction must be written to both the online redo log and to at least one standby database before the transaction commits. To ensure that data loss cannot occur, the primary database will shut down, rather than continue processing transactions.

How to create Oracle directory?

Database Directories are required to read/write to a filesystem location from plsql code.

Below is the syntax to create database directory

SQL> create directory PLSQL_DIR AS '/oratmp/code';

Directory created.

Grant Read/write privileges to Required Schema

SQL> GRANT READ,WRITE ON DIRECTORY PLSQL_DIR TO APPS;

Grant succeeded.