DB Link to Physical Standby

How can we execute explain plan for queries connecting to Physical standby database over DB link.
explain plan for select * from test.test_table@stby;
Getting ORA-16000 when trying to that.
Tried to set transaction to read only.
Then tried to run explain plan, that gives error for ora-02047 cannot join the distributed
Any insight will be appreciated.
MM

You cannot use "explain plan" as it means inserting into "plan_table" table. So your standby is in read only mode, isnt it :)
Activate the sql trace and execute the query
Best would be convert your standby to snapshot standby :), Use it for any kind of testing like explain plan or even run that query and monitor, when you are satisfied come back to physical standby.
Perform the following steps to convert a physical standby database into a snapshot standby database:
Stop Redo Apply, if it is active.
On an Oracle Real Applications Cluster (RAC) database, shut down all but one instance.
Ensure that the database is mounted, but not open.
Issue the following SQL statement to perform the conversion:
SQL> ALTER DATABASE CONVERT TO SNAPSHOT STANDBY;
The database is dismounted after conversion and must be restarted.
Edited by: Karan on Feb 8, 2013 12:00 AM

Similar Messages

DB link for physical standby database

Hi All ,
I'm facing the below error on primary while trying to create a db link pointing to the 10g standby database which is in mount stage.
SQL> create database link synct connect to system identified by 123 using 'stdby';
Database link created.
SQL> select max(sequence#) from v$archived_log@synct where applied='YES';
select max(sequence#) from v$archived_log@synct where applied='YES'
ERROR at line 1:
ORA-02068: following severe error from SYNCT
ORA-01033: ORACLE initialization or shutdown in progress
Database version is 10.2 standard edition
My requirement is i need to get max(sequence#) of standby database from primary database using db link.
what i was trying to do is
on primary get max(sequence#) & get max(sequence#) of standby using db link and compare both if the gap differene is more than 10 send a mail.
Any suggestions will be really helpful

976422 wrote:
Hi All ,
I'm facing the below error on primary while trying to create a db link pointing to the 10g standby database which is in mount stage.
SQL> create database link synct connect to system identified by 123 using 'stdby';
Database link created.
SQL> select max(sequence#) from v$archived_log@synct where applied='YES';
select max(sequence#) from v$archived_log@synct where applied='YES'
ERROR at line 1:
ORA-02068: following severe error from SYNCT
ORA-01033: ORACLE initialization or shutdown in progress
Post Standby/DataGuard/ADG all questions further in Oracle Discussion Forums » High Availability » Data Guard
If you try to connect any users other than SYS in standby the error is very much expected. Of course you can connect with other users if you open database in OPEN READ ONLY mode, from 11gRx you can connect with other users even MRP is running if you are using ADG(active Data Guard licensed) .
I like to know, what you want to achieve by creating DB Link on physical standby database? Which is not allowed.
Database version is 10.2 standard edition
My requirement is i need to get max(sequence#) of standby database from primary database using db link.
what i was trying to do is
on primary get max(sequence#) & get max(sequence#) of standby using db link and compare both if the gap differene is more than 10 send a mail.
Any suggestions will be really helpfulNote:- Standard edition, Data Guard not enabled.
To use this you should use Oracle Net Service, you no need of DB Links.
Ex:- sqlplus sys/****@standby as sysdba
Here standby refers to Oracle net service, Where you will have entries in $ORACLE_HOME/network/admin/tnsnames.ora file.
Edited by: CKPT on Dec 12, 2012 2:01 PM

Data guard synchronization after link down b/w primary and physical standby

Hi All,
I have configured data guard on oracle 11gr2 db. Normally switchover between my primary and physical standby happens smoothly and the Apply lag would be zero. Recently We had to test a scenario when the network link between Primary and Physical standby is completely down and Physical standby is isolated completely for more than half an hour.
When we brought up the link every thing worked smoothly but apply lag started increasing from 0 to around 3 hrs. And then it started reducing to 0. Currently Apply lag and transport lag shows 0.
But is this normal behaviour of oracle data guard that when the link between primary and physical standby is completely down, It requires 3-4 hrs for resynchronization ??? Even when during isolation, there were very few transactions happend on primary database ??
Are there any documents available for this scenario??
Thanks

Hi, after the link is up, if there were some transactions and produced archive logs it's normal to take some time for resync. To check if 3-4 hours is normal or not, you can repeat the scenario and this time check
- how many archivelogs does primary produce in this period.
- after the link is up, does archivelog transfer immediately starts from primary to standby? Is primary able to send these archivelogs parallel?
- Is there anything wrong with the apply process?
check primary & standby alert log files, and run this query on standby to check the transport and apply processes:
SELECT PROCESS, STATUS, THREAD#, SEQUENCE#, BLOCK#, BLOCKS FROM V$MANAGED_STANDBY;
regards

Folders created thru DB link not showing in Discoverer on physical Standby

Hi All,
We are using Oracle Database 10g Enterprise Edition Release 10.2.0.4.0. We have configured a physical standby database that we open in read only mode for reporting purpose.
We have configured the Oracle Discoverer 9.0.2.00.00 for reporting on both production and physical standby.
We have another database called legacy database, we moved 3 years old data from production to legacy database.
To access some legacy tables from production we have created a DB link in production and we have also added these tables in discoverer thru DB Link.
Now when user executes the discoverer desktop from standby database, the folders pointing the legacy database are not showing, while when we connect thru Discoverer Administrator it is showing in EUL.
I then connected to standby database thru a user and executed a select statement as
Select id, performed, performer from my_events@bkuplnk it gives me below error,
ORA-16000 database link read only query fails on physical standby 10.2.4.0Then I execute the command
Set transaction read only; and execute the select statement, it gave me results.
After that I have started the physical standby database in read only mode and issue the command set transaction read only as SYS user , but in discoverer desktop these folders are still not available

Hi,
The folders are not showing up in Desktop because the folder was not valid when the business area was opened from Desktop. By default, Discoverer checks the metadata for all the folders in a business area when the BA is opened. I think there is a preference you can set to change this behaviour so that Discoverer so not validate folders.
Usually with database links you are better off hiding the link in a database view so that the metadata for the folder is held locally.
Rod West

Logical and Physical Standby Practice

Hello Gurus
I am now attempting to practice Oracle Data Guard and in this direction I understand since 10g we have logical standby server as well as a physical standby server. While I am gathering information and knowledge about the data guard as is and varisous modes and types possible with oracle 10g and 11g in specific, an attempt to upgrade my self and learn these set-ups and understand them in detail.. I come to you for some guidence..
I am referring to Oracle Documentation for these details. At the same time I also approach you to share your experiences .. may be a link apart from the documentation of oracle which you might want to refer me to use as a quick reference.. some thing that a person like me .. fairly new to this set-up understand it and then attempt to come up with one..
This is for my practise and learning purpose.
Sarat.

Logical Standby was already introduced in 9i. It differs from physical standby in the way, the redo protocol, transmitted from the primary, gets used to actualize the standby. With logical standby, you have SQL APPLY - basically, we try to generate the same SQL that was done on the primary from the redo protocol that was written on behalf of that SQL on the primary. That SQL then is done on the OPEN instance at the logical standby.
In case of a physical standby, the redo protocol from the primary is used to do RECOVERY - called REDO APPLY - to actualize the standby.
Since 10g, the sames protection levels can be achieved with logical or physical standby.
Drawback of logical standby: Not all kinds of SQL and all datatypes are supported
Drawback of physical standby: It is mounted (versions before 11g) while being recoverd - or in 11g, REDO APPLY in READ ONLY status is possible but comes with an extra charge (ACTIVE DATA GUARD feature).
If you look on my Blog, I have some examples about creating physical & logical standby DBs
Kind regards
Uwe
http://uhesse.wordpress.com

How Real Time Apply works while physical standby is open in Read Only mode

Hi,
With Active data guard option, we can open physical standby DB in read only mode, while redo log are being applied. (Real Time Query)
Standby Redo log (SRL) enables Real Time Apply (with "USING CURRENT LOGFILE" clause in recover database command on standby DB)
I am interested to know, how Real Time Query works ?
What is the mechanism with allows us to open physical standby DB in read only mode while redo logs are being applied continuously ?
Regards,
Sujit

Dear user7419391,
That is a new feature in Oracle Database 11g. MRP can use the real time apply in 10g but the concept here is different.
Taken from the following document;
http://www.ascent.co.za/documents/oracle/Oracle%20databse%2011g%20Active-Data-Guard%20datasheet.pdf
*Unique Advantages of Oracle Active Data Guard*
+Active Data Guard is an evolution of Data Guard technology, providing unique+
+performance advantages while leveraging all other enhancements included in Oracle+
+Data Guard 11g. For example, any Data Guard 11g physical standby database can+
+be easily converted to a Snapshot Standby. A Snapshot Standby is open read-write+
+and is ideally suited as a test system, able to process transactions independent of the+
+primary database. A Snapshot Standby maintains protection by continuing to receive+
+data from the production database, archiving it for later use. When tests are+
+complete, a single command discards changes made while open read-write and+
+quickly resynchronizes the standby database with the primary.+
The other link in the previous post is excellent and you really have to read it to understand the active data guard aspects.
Regards.
Ogan

Error raised when opening physical standby in read only

Hi,
I've a physical standby 11.2.0.2 created using RMAN duplicate from active database which is configured with data guard. When I open the database in READ ONLY mode
SQL> alter database open read only;
Database altered.
SQL> select open_mode from v$database;
OPEN_MODE
READ ONLY
I get this error in the alert log
Physical standby database opened for read only access.
Fri Aug 12 15:14:01 2011
db_recovery_file_dest_size of 256000 MB is 4.72% used. This is a
user-specified limit on the amount of space that will be used by this
database for recovery-related files, and does not reflect the amount of
space available in the underlying filesystem or ASM diskgroup.
Errors in file /oradata/admin/ORAINT/diag/diag/rdbms/oraintsb/oraintsb/trace/ora intsb_ora_8692.trc:
ORA-00604: error occurred at recursive SQL level 1
ORA-00931: missing identifier
ORA-06512: at "SYS.DBMS_UTILITY", line 156
ORA-06512: at "SYS.DBMS_SHARED_POOL", line 72
ORA-06512: at "SYS.DBMS_SHARED_POOL", line 84
ORA-06512: at "SYS.PROC_PKGS_KEEP", line 26
ORA-06512: at line 2
Completed: alter database open read only
the tracefile is showing this,
Trace file /oradata/admin/ORAINT/diag/diag/rdbms/oraintsb/oraintsb/trace/oraintsb_ora_8692.trc
Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
ORACLE_HOME = /opt/oracle/product/11.2.0/ORAINT
System name: Linux
Node name: c4p-db01
Release: 2.6.18-194.0.0.0.3.el5xen
Version: #1 SMP Mon Mar 29 18:27:00 EDT 2010
Machine: x86_64
VM name: Xen Version: 3.4 (PVM)
Instance name: oraintsb
Redo thread mounted by this instance: 1
Oracle process number: 17
Unix process pid: 8692, image: oracle@c4p-db01 (TNS V1-V3)
*** 2011-08-12 15:14:03.367
*** SESSION ID:(24.1) 2011-08-12 15:14:03.367
*** CLIENT ID:() 2011-08-12 15:14:03.367
*** SERVICE NAME:(SYS$USERS) 2011-08-12 15:14:03.367
*** MODULE NAME:(sqlplus@c4p-db01 (TNS V1-V3)) 2011-08-12 15:14:03.367
*** ACTION NAME:() 2011-08-12 15:14:03.367
Error in executing triggers on database startup
*** 2011-08-12 15:14:03.367
dbkedDefDump(): Starting a non-incident diagnostic dump (flags=0x0, level=0, mask=0x0)
----- Error Stack Dump -----
ORA-00604: error occurred at recursive SQL level 1
ORA-00931: missing identifier
ORA-06512: at "SYS.DBMS_UTILITY", line 156
ORA-06512: at "SYS.DBMS_SHARED_POOL", line 72
ORA-06512: at "SYS.DBMS_SHARED_POOL", line 84
ORA-06512: at "SYS.PROC_PKGS_KEEP", line 26
ORA-06512: at line 2
if I disable the system triggers using
ALTER SYSTEM SET "_system_trig_enabled"=FALSE scope=both;
The error doesn't appear but when trying to switch to active dataguard the open_mode goes from READ ONLY to MOUNTED rather than READ ONLY WITH APPLY
Any help much appreciated
Edited by: phil74 on 12-Aug-2011 07:22

Have you checked what your guard status is set to?
SQL> SELECT guard_status from v$database;I've had a similar issue before but with a standby, whereby the status was set to ALL. This means all users apart from SYS are unable to make changes on the database.
My resolution was to set the status to standby:
SQL> ALTER DATABASE GUARD STANDBY;You may wish to set the guard status to NONE however.
I took some notes:
http://juniororacledba.wordpress.com/2011/07/17/oracle-logical-standby-dataguard-error However, I do not have a link to any Oracle documentation on the subject to hand. But might give you a head start.

Enterprise Manager on Physical Standby

Hi,
I have switched over from my production database to the physical standby database as the production failed. When I try to use the Enterprise Manager on the new production database (previous standby) I get problems.
Basically when I try to click on any of the links such as 'performance' etc EM attempts to log me into the old production database. I get the login screen to login to the previous production database. Seems that this information (connection string / ip address to the database) is somehow in the config. Is there anyway to reset EM to say - yes this physical standby in now in charge - please use this connection! or do I have to uninstall and re-install EM??
Anyone ever try this.
thx.
S.

Solved!
The problem is that the standby server has a different IP address from that of the production. EM writes the IP address to some config tables so when the IP address changes you cannot use EM again until you change these values. Not documented anywhere.
Once I changed these values everything was working as normal.

RE logical/physical standby database

1. Why logical standby database is SQL apply, and Physical standby database is redo apply? What ‘s the meaning/objective for that? (pls don’t tell me what is SQL/redo apply)
2. As we know, a logical standby database can be used for reporting and querying if primary database is down, why we still need a physical standby database (it can’t do that during recovering process, it just a same copy of primary database)? Why not just go ahead to set up only a perfect logical standby database? (just because logical one can’t accommodate all kinds of data type???)
3. Combined with Real time Apply and maximum protection, we can achieve a zero data loss, but could we achieve a zero downtime? Why or why not?

Go Through Below link
>>>Can you convert a Logical standby to a Physical Standby?

ASM_PRIMARY_to_ASM PHYSICAL STANDBY

HI All,
Can any one please share Some good documents for creating - ASM primary to ASM standby creation .
any links...
PRIMARY AND STANDBY:
in ASM : Datafiles in +DATA01 archive in +FRA01
DB - 11gR2
OS - Linux-64 bit.
using +FRA01 for archive dest.
Thanks,

Hello;
http://askdba.org/weblog/oracle11g/dataguard/11gr2-rac-dataguard-setup-using-asm/
Data Guard &#8211; ASM primary to filesystem physical standby &#8211; using RMAN duplicate | 老庞闲话
Dataguard DB/LOG FILE NAME CONVERT has been set but files are created in a different directory (Doc ID 1348512.1)
Clarification on Data Guard Broker Config Files in ASM (Doc ID 1508241.1)
Creating a physical standby from ASM primary (Doc ID 787793.1)
Best Regards
mseberg

About physical standby database

We have physical standby database(10g). what are steps to put standby database in ready only mode for time being and then put it back in primary-secondary relationship once cheking is done?

Cancel the redo Apply
SQL>ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;Open The database
SQL>ALTER DATABASE OPEN;Do your stuff.
Once done, shut it down, then mount it again and resume the redo apply
SQL>SHUTDOWN IMMEDIATE;
SQL>STARTUP NOMOUNT;
SQL>ALTER DATABASE MOUNT STANDBY DATABASE;
SQL>ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT;If you use real-time redo apply, you may want to issue the following command instead of the previous one.
SQL>ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT;...and pretty much that is it.
Be aware that while running it in read-only mode, no logs from the primary are being applied. Also you may hit some bugs when you open your standby database. So if this standby is your production one, make sure you know how to deal in a situation when you need to resolve possible issues.
Jason Arnell has explained one possible buggy scenario on his blog - LINK.
--Mihajlo

Question-Recovering tablespace in physical Standby...Oracle 10g?

Hello:
I have an interesting issue. I thought I will ask the group.
I have a physical standby database in 10g. Once of the datafile is in inconsistent state due to a crashed DB during recovery from the last time around.
I do not have any archivelogs, either on standby or primary .. Unfortunately.
However, the primary database is alive and well.
How do I recover my datafile selectively? Is a complete restore/recreation of the standby is the only option?
Any ideas?
Thanks in advance.
Ganesh

read that link
http://download.oracle.com/docs/cd/B19306_01/server.102/b14239/scenarios.htm#CIHIAADCKhurram

How to create physical standby database without dataguard

Hi,
Can anyone please help me how to create Physical Standby Database without dataguard. As i am using Oracle 10.2.0.1 Standard Edition for production databases.
Please find the specifications of my server :
Database : Oracle 10.2.0.1(Standard Edition)
Server : Linux 4.0(32 bit machine)
As we know that Dataguard cannot be created in Standard Edition as we dont have that option in this edition. So please help me how to create the physical standby database.
Thanks in advance.
Regards,
Farooq

Hello,
I hope this link helps you out...
http://download.oracle.com/docs/cd/B19306_01/server.102/b14239/rcmbackp.htm
http://www.dbasupport.com/oracle/ora10g/manual_standby.shtml
Thanks & Regards
Pratik Lakhpatwala
Jr Oracle DBA
Edited by: Pratik.L on Dec 31, 2009 12:03 PM

Physical standby database, dblinks derived frn schemas help

I observed that many of the procedure,function,trigger of the database using dblinks which are derived from two schemas within the same database (i.e. eg: DBlink "CIS_TO_HIS" created in CISPROD schema connecting HISPROD schema of the same database). Now Oracle doesn't recommend this type of coding as a suitable.
But I am more concerned about implementing the same code over data guard in Physical standby database as it will be in read only mode and will have different TNS names entry. Therefore since database link uses TNS entry and physical standby would be using a separate TNS entry from primary, this might be a risk of transaction using those dblinks will fail. Hence can you please let me know the risk areas in physical standby of using dblink within same database?

The best solution for you is to stop using DB links between different DB schemas in the same DB.
If you do not use RAC, one workaround would be to use the loopback IP (127.0.0.1) to define your TNS connection over.
<Your DB>=
(DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)
(HOST = 127.0.0.1)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = <Your DB>)))That way, if you hit the production server, the TNS will lead you to the production DB, and if you hit the standby server, you’ll go to the standby DB.
You would need to create another TNS entry for the production DB on the standby server and use it for standby replication.
Since this change might affect production operation and failover abilities, you need to thoroughly test it.
Iordan Iotzov
http://iiotzov.wordpress.com/

Physical standby database fail-over

Hi,
I am working on Oracle 10.2.0.3 on Solaris SPARC 64-bit.
I have a Dataguard configuration with a single Physical standby database that uses real time application. We had a major application upgrade yesterday and before the start of upgrade, we cancelled the media recovery and disabled the log_archive_dest_n so that it doesn't ship the archive logs to standby site. We left the dataguard configuration in this mode incase of a rollback.
Primary:
alter system set log_archive_dest_state_2='DEFER';
alter system switch logfile;
Standby:
alter database recover managed standby database cancel;Due to application upgrade induced problems we had to failover to the physical standby, which was not in sync with primary from yesterday. I used the following method to fail-over since i do not want to apply any redo from yesterday.
Standby:
alter database activate physical standby database;
alter database open;
shutdown immediate;
startupSo, after this step, the database was a stand alone database, which doesn't have any standby databases yet (but it still has log_archive_config parameter set and log_archive_dest_n parameters set but i have 'DEFER' the log_archive_dest_n pointing to the old primary). I have even changed the "archive log deletion policy to NONE"
RMAN> configure archivelog deletion policy to none;After the fail-over was completed, the log sequence started from Sequence 1. We cleared the FRA to make space for the new archive logs and started off a FULL database backup (backup incremental level 0 database plus archivelog delete input). The backup succeded but we got these alerts in the backup log that RMAN cannot delete the archivelogs.
RMAN-08137: WARNING: archive log not deleted as it is still neededMy question here is
1) Even though i have disabled the log_archive_dest_n parameters, why is RMAN not able to delete the archivelogs after backup when there is no standby database for this failed-over database?
2) Are all the old backups marked unusable after a fail-over is performed?
FYI... flashback database was not used in this case as it did not server our purpose.
Any information or documentation links would be greatly appreciated.
Thanks,
Harris.

Thanks for the reply.
The FINISH FORCE works in some cases but if there is an archive gap (though it didn't report in our case), it might not work some times (DOCID: 846087.1). So, we followed the Switch-over & Fail-Over best practices where it mentioned about this "ACTIVE PHYSICAL STANDBY" for a fail-over if you intend not to apply any archivelogs. The process we followed is the Right one.
Anyhow, we got the issue resolved. Below is the resolution path.
1) Even though if you DEFER the LOG_ARCHIVE_DEST_STATE_N parameter's on the primary, there are some situations where the Primary database in a dataguard configuration where it will not delete the archive logs due to some SCN issues. This issue may or may not arise in all fail-over scenarios. If it does, then do the following checks
Follow DOCID: 803635.1, which talks about a PLSQL procedure to check for problematic SCN's in a dataguard configuration even though the physical standby databases are no available (i.e., if the dataguard parameters are set, log_archive_config, log_archive_dest_n='SERVICE=..." still set and even though corresponding LOG_ARCHIVE_DEST_STATE_N parameters are DEFERRED).
If this procedure returns any rows, then the primary database is not able to delete the archivelogs because it is still thinking there is a standby database and trying to save the archive logs because of the SCN conflict.
So, the best thing to do is, remove the DG related parameters from the spfile (log_archive_config, log_archive_dest_n parameters).
After i made these changes, i ran a test backup using "backup archivelog all delete input", the archive logs got deleted after backup without any issues.
Thanks,
Harris.
Edited by: user11971589 on Nov 18, 2010 2:55 PM

DB Link to Physical Standby

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