Confusion regarding logical standby database

While designing the logical standby database, Oracle recommends to add the supplement information in the primary database, so that the changed columns are uniquely recorded in redo log file.
In this case the amount of information in redo log files will increase,
So, redo log files will be filled on a faster basis and more archive log will be created, increasing the overhead on background proccess
Should such a trade -off be kept??

I believe Oracle does more than recommend that supplemental logging is enabled. In the Data Guard Concepts and Administration manual
http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96653/create_ls.htm#1071780
"Supplemental logging must be enabled on the primary database before you create the logical standby database."
Yes, this adds to the work that the primary database has to do, but that's the trade-off you get for having a logical standby. If you don't want this extra overhead, you might consider using a physical standby.
Justin
Distributed Database Consulting, Inc.
http://www.ddbcinc.com/askDDBC

Similar Messages

Logical Standby Database in NOARCHIVE Mode

Hi,
I have configured a Logical Standby Database for Reporting purposes. A Physical Standby Database is running for MAA. i.e. in case of Role Transition (switch/Failover) the Physical Stdby Db will get the role of the Primary.
The logical standby database is creating a lot of Archive Redologs files, nearly every minute. Redolog files are 50MB and there is no work done in db during the time. I'm NOT using Standby Redolog files.
Is there a need for logical standby database to be in NOARCHIVELOG mode? The Primary is definatley in ARCHIVELOG mode.
Thanks for any responses.
regards
Sahba

hi,
well there are two things to the above:-
1. there was an archive file nearly every minute:
this is due to a db recovery. for some reason, the db was in inconsistent state, after a sudden shutdownof the OS. I was on a test environment, on windows vista, unfortunately. unimportant ... a reboot solved it.
2. Logical standby db in NOARCHIVE MODE when setup for the purpose of Reporting.
As long as the MAA configured for the primary db, such as physical standby db, and a second, the logical standby db setup purely for the purpose of reporting, which then can run with NOARCHIVELOG mode, after converting the physical standby db to logical.
logical standby db uses Streams architecture, so this method brings cost, time and performance advantages to the customer.
regards
Sahba

Creation of Logical Standby Database Using RMAN ACTIVE DATABASE COMMAND

Hi All,
I am in confusion how to create logical standby database from primary database using rman active database command.
What i did:-
Create primary database on machine 1 on RHEL 5 with Oracle 11gR2
Create standby database on machine 2 on RHEL 5 With Oracle 11gR2 from primary using RMAN active database command
Trying to create logical standby database on machine 3 on RHEL 5 with Oracle 11gR2 using RMAN active database command from primary.
The point which confuse me is to start the logical standby in nomount mode on machine 3 with which pfile like i create the pfile for standby database do i need to create the pfile for logical standby db.
I done the creation of logical standby database by converting physical standby to logical standby database
I am following the below mentioned doc for the same:
Creating a physical and a logical standby database in a DR environment | Chen Guang&#039;s Blog
Kindly guide me how to work over the same or please provide me the steps of the same.
Thanks in advance.

Thanks for your reply
I already started the logical standby database with pfile in nomount mode. And successfully completed the duplication of database. by mentioning the DB_FILE_NAME_CONVERT and LOG_FILE_NAME_CONVERT parameter.
But i am not able to receive the logs on the above mentioned blog i run the sql command to check the logs but getting "no rows selected"
My primary database pfile is:
pc01prmy.__db_cache_size=83886080
pc01prmy.__java_pool_size=12582912
pc01prmy.__large_pool_size=4194304
pc01prmy.__oracle_base='/u01/app/oracle'#ORACLE_BASE set from environment
pc01prmy.__pga_aggregate_target=79691776
pc01prmy.__sga_target=239075328
pc01prmy.__shared_io_pool_size=0
pc01prmy.__shared_pool_size=134217728
pc01prmy.__streams_pool_size=0
*.audit_file_dest='/u01/app/oracle/admin/pc01prmy/adump'
*.audit_trail='db'
*.compatible='11.1.0.0.0'
*.control_files='/u01/app/oracle/oradata/PC01PRMY/controlfile/o1_mf_91g3mdtr_.ctl','/u01/app/oracle/flash_recovery_area/PC01PRMY/controlfile/o1_mf_91g3mf6v_.ctl'
*.db_block_size=8192
*.db_create_file_dest='/u01/app/oracle/oradata'
*.db_domain=''
*.db_file_name_convert='/u01/app/oracle/oradata/PC01SBY/datafile','/u01/app/oracle/oradata/PC01PRMY/datafile'
*.db_name='pc01prmy'
*.db_recovery_file_dest='/u01/app/oracle/flash_recovery_area'
*.db_recovery_file_dest_size=2147483648
*.diagnostic_dest='/u01/app/oracle'
*.dispatchers='(PROTOCOL=TCP) (SERVICE=pc01prmyXDB)'
*.fal_client='PC01PRMY'
*.fal_server='PC01SBY'
*.log_archive_config='DG_CONFIG=(pc01prmy,pc01sby,pc01ls)'
*.log_archive_dest_1='LOCATION=/u01/app/oracle/flash_recovery_area/PC01PRMY/ VALID_FOR=(ONLINE_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=pc01prmy'
*.log_archive_dest_2='SERVICE=pc01sby LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=pc01sby'
*.log_archive_dest_3='SERVICE=pc01ls LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES, PRIMARY_ROLE) DB_UNIQUE_NAME=pc01ls'
*.log_archive_dest_state_1='ENABLE'
*.log_archive_dest_state_2='DEFER'
*.log_archive_dest_state_3='DEFER'
*.log_archive_max_processes=30
*.log_file_name_convert='/u01/app/oracle/oradata/PC01SBY/onlinelog','/u01/app/oracle/oradata/PC01PRMY/onlinelog'
*.open_cursors=300
*.pga_aggregate_target=78643200
*.processes=150
*.remote_login_passwordfile='EXCLUSIVE'
*.sga_target=236978176
*.undo_tablespace='UNDOTBS1'
My logical standby pfile is:-
pc01ls.__db_cache_size=92274688
pc01ls.__java_pool_size=12582912
pc01ls.__large_pool_size=4194304
pc01ls.__oracle_base='/u01/app/oracle'#ORACLE_BASE set from environment
pc01ls.__pga_aggregate_target=79691776
pc01ls.__sga_target=239075328
pc01ls.__shared_io_pool_size=0
pc01ls.__shared_pool_size=125829120
pc01ls.__streams_pool_size=0
*.audit_file_dest='/u01/app/oracle/admin/pc01ls/adump'
*.audit_trail='db'
*.compatible='11.1.0.0.0'
*.control_files='/u01/app/oracle/oradata/PC01LS/controlfile/o1_mf_91g3mdtr_.ctl','/u01/app/oracle/flash_recovery_area/PC01LS/controlfile/o1_mf_91g3mf6v_.ctl'
*.db_block_size=8192
*.db_create_file_dest='/u01/app/oracle/oradata'
*.db_domain=''
*.db_file_name_convert='/u01/app/oracle/oradata/PC01SBY/datafile','/u01/app/oracle/oradata/PC01PRMY/datafile'
*.db_name='pc01prmy'
*.db_unique_name='pc01ls'
*.db_recovery_file_dest='/u01/app/oracle/flash_recovery_area'
*.db_recovery_file_dest_size=2147483648
*.diagnostic_dest='/u01/app/oracle'
*.dispatchers='(PROTOCOL=TCP) (SERVICE=pc01prmyXDB)'
*.log_archive_config='DG_CONFIG=(pc01prmy,pc01sby,pc01ls)'
*.log_archive_dest_1='LOCATION=/u01/app/oracle/flash_recovery_area/PC01PRMY/ VALID_FOR=(ONLINE_LOGFILES,ALL_ROLES) DB_UNIQUE_NAME=pc01prmy'
*.log_archive_dest_2='LOCATION=/u01/app/oracle/flash_recovery_area/PC01LS/ VALID_FOR=(STANDBY_LOGFILES,STANDBY_ROLE) DB_UNIQUE_NAME=pc01ls'
*.log_archive_dest_3='SERVICE=pc01ls LGWR ASYNC VALID_FOR=(ONLINE_LOGFILES, PRIMARY_ROLE) DB_UNIQUE_NAME=pc01ls'
*.log_archive_dest_state_1='ENABLE'
*.log_archive_dest_state_2='ENABLE'
*.log_archive_max_processes=30
*.log_file_name_convert='/u01/app/oracle/oradata/PC01SBY/onlinelog','/u01/app/oracle/oradata/PC01PRMY/onlinelog'
*.open_cursors=300
*.pga_aggregate_target=78643200
*.processes=150
*.remote_login_passwordfile='EXCLUSIVE'
*.sga_target=236978176
*.undo_tablespace='UNDOTBS1'
Kindly advice over the same

Logical Standby Database and XMLDB

I couldn't find a proper group to post this message and thought I would try here.
I want to set up a Logical Standby Database for our production database server 9.2.0.4.0 with XMLDB. I am having problem with some system tables that were created when I registered some XML schemas.
These tables are in the standby database but Oracle complains the object does not exist.
Any idea?

>
The "may be" is because I have tested flashback of a physical standby to before resetlogs, but not a logical standby.
>
A physical standby keeps the DBID of the primary - a logical standby does not. That is exactly the problem that restricts the reconversion into physical from logical, and you did not encounter that problem.
>
I haven't used "keep identity" but from what I read it relates to "convert to physical" not "flashback database".
>
Exactly. And that is what the OP wants to do: convert to physical (from logical).
You mentioned that this might be possible with flashback.
Problem: During the conversion from physical to logical, the DBID gets changed unless you specify (in 11g) KEEP IDENTITY. This would make it possible to reconvert into phyiscal from logical.
In short: If there is no solution for the changed DBID of the logical standby in order to flashback it into physical as you suggested, then it is not possible .
When I saw your first answer, I thought that you might have a solution in mind in order to solve that obvious problem. Sorry for having bothered you.
Kind regards
Uwe
http://uhesse.wordpress.com

Logical Standby databases

Hi,
When we say "Logical Standby Databases are logically identical to primary databases although the physical organization and structure of the data can be different." what does it exactly means?
Does it mean that in logical standby tablespace name, schema name, table name, column names etc can be different and still has the same data as primary?
Does it mean that we can exclude indexes and constraints as present in primary?
Only the data should match with primary word by word, value by value?
I am asking this as i have never worked in a logical standby database but i seriously want to know.
Please answer.
Regards,
SID

Physical standby differs from logical standby:
Physical standby schema matches exactly the source database.
Archived redo logs and FTP'ed directly to the standby database which is always running in "recover" mode. Upon arrival, the archived redo logs are applied directly to the standby database.
Logical standby is different from physical standby:
Logical standby database does not have to match the schema structure of the source database.
Logical standby uses LogMiner techniques to transform the archived redo logs into native DML statements (insert, update, delete). This DML is transported and applied to the standby database.
Logical standby tables can be open for SQL queries (read only), and all other standby tables can be open for updates.
Logical standby database can have additional materialized views and indexes added for faster performance.
Installing Physical standbys offers these benefits:
An identical physical copy of the primary database
Disaster recovery and high availability
High Data protection
Reduction in primary database workload
Performance Faster
Installing Logical standbys offer:
Simultaneous use for reporting, summations and queries
Efficient use of standby hardware resources
Reduction in primary database workload
Some limitations on the use of certain datatypes

Logical standby database to physical standby database

I already start my logical standby database and I want to return it again to physical standby database. So what should I do?

>
The "may be" is because I have tested flashback of a physical standby to before resetlogs, but not a logical standby.
>
A physical standby keeps the DBID of the primary - a logical standby does not. That is exactly the problem that restricts the reconversion into physical from logical, and you did not encounter that problem.
>
I haven't used "keep identity" but from what I read it relates to "convert to physical" not "flashback database".
>
Exactly. And that is what the OP wants to do: convert to physical (from logical).
You mentioned that this might be possible with flashback.
Problem: During the conversion from physical to logical, the DBID gets changed unless you specify (in 11g) KEEP IDENTITY. This would make it possible to reconvert into phyiscal from logical.
In short: If there is no solution for the changed DBID of the logical standby in order to flashback it into physical as you suggested, then it is not possible .
When I saw your first answer, I thought that you might have a solution in mind in order to solve that obvious problem. Sorry for having bothered you.
Kind regards
Uwe
http://uhesse.wordpress.com

Logical Standby Database with 10g+ASM on both sides??

Hi out there,
is there a known way to establish a logical standby database on 10g, if both
sides are running with an ASM setup?
I've tried to create one out of a physical standby database (which is set up
and running w/o any problems), like a book suggested me to do.
The procedure was:
1. switch on supplemental logging
2. prepare initiation parameters (for archive logging etc.) on both sides for
logical stb.
3. shut down the phyiscal standby
4. alter database create logical standby controlfile as '<path>'; on the
primary, transfer the controlfile to the standby db. Here I had to use RMAN
to copy the controlfile into the ASM System, and modify the initfile/spfile
in order to use the controlfile. No problem so far.
5. mount the standby database, alter database recover managed standby database
disconnect; -> At this point, the alert log complained about non-available
datafiles.
6. alter database activate standby database; --> fails ("needs recovery") due
to last point.
The trouble is, the controlfile created at point 4 cointains wrong paths to
the datafiles. Since I can not have the same disk group name on the standby
system, and since ASM renames the stored datafiles by its own, the complaints
of point 5 are comprehensible, but nevertheless annoying.
I tried to backup a controlfile to trace and change the paths, but at after
mounting the standby with this controlfile and proceeding at point 5, the
system says "<path> is not a standby controlfile"
Is there a different way of creating a "Logical Standby Database with 10g+ASM
on both sides"? Metalink said nothing about LogStby and ASM.
Best regards and thanks in advance,
Martin

I'm not sure if this will work but try:
1. create trace control file (you did it)
2. change paths (you did it)
3. recrate control file (you did it)
... there was error occured during mount before
so mount database (not as standby)
4. create standby control file (from recreated control file)
5. shutdown instance, replace control file with new standby control file or replace the control filename in parameter file.
6. mount as standby
What happend?
Update: Tested on my side and it has worked fine... How about you?
Message was edited by:
Ivan Kartik

Creating new tables in Logical Standby database

Hi
I have a requirement to create new tables in logical standby database. These tables will not be present on primary database. Is it possible to do this ?
I have a new schema already created which has the privilege to CREATE new table.
I have stopped the logical standby apply.
When I am now trying to create a new table but it is failing with error : insufficient privileges.
When I am trying to run below statement on new schema it is also failing with error of insufficient privileges.
alter session disable dataguard;
Please help.

user8819121 wrote:
Thanks Mahir,
I was able to create the table after logging in as sysdba.
But I need my user on that table to execute DML statements. My user has privileges to insert,delete and update any table.
I tried the following statements to disable the guard but it is sill not working
ALTER DATABASE GUARD STANDBY.
Do I need to skip the tables created using dbms_logstdby package to not making it part of SQL Apply ? I guess not since the table is not in primary database.
Amit
You can skip only on primary, your created schema on Standby is not in primary.
Then you must change Status of data guard to NONE. NONE is means is not any security on your data.
In Guard status NONE can change all schema data.
Please check link: http://docs.oracle.com/cd/E11882_01/server.112/e10700/manage_ls.htm#CHDGFGHG
Following tests on user created before guard status is change from ALL to STANDBY.
C:\Users\Administrator>sqlplus / as sysdba
SQL> conn test/test
Connected.
SQL> select table_name from user_tables;
TABLE_NAME
T
SQL> insert into t values(22);
insert into t values(22)
ERROR at line 1:
ORA-16224: Database Guard is enabled
SQL> conn / as sysdba
Connected.
SQL> select guard_Status from v$database;
GUARD_S
ALL
SQL> alter database guard standby;
Database altered.
SQL> conn test/test
Connected.
SQL> insert into t values(1);
insert into t values(1)
ERROR at line 1:
ORA-16224: Database Guard is enabled
SQL> conn / as sysdba
Connected.
SQL> select guard_Status from v$database;
GUARD_S
STANDBY
SQL> alter database guard none;
Database altered.
SQL> select guard_Status from v$database;
GUARD_S
NONE
SQL> conn test/test
Connected.
SQL> insert into t values(1);
1 row created.
SQL> commit;
Commit complete.And Now I want share with you new tests :)
Now user creating when after guard status change
SQL> drop user test cascade;
User dropped.
SQL> select guard_status from v$database;
GUARD_S
STANDBY
SQL> create user test identified by test;
User created.
SQL> grant create session, resource, create table to test;
Grant succeeded.
SQL> conn test/test
Connected.
SQL> create table t (n number);
Table created.
SQL> insert into t values(1);
1 row created.
SQL> commit;
Commit complete.
SQL>It means when guard status is ALL then all of user created guarding.
When you changed status to STANDBY then Logical Standby guard only primary schema and created schema before change.
NONE is not guard any schema. it means you can delete standby schema data too.
Regards
Mahir M. Quluzade
Edited by: Mahir M. Quluzade on Apr 19, 2013 4:07 PM

Steps to rollback when Logical Standby Database creation fails

Hi,
In case while creating a logical standby database it fails. What steps should be done on primary to rollback the earlier steps. Because while creating logical standby we do certain tasks on primary e.g.
1) create supplemental logging.
2) update init file.
Regards,
Tushar

Hi,
Thanks for the mail. Should I drop the supplemental logging using
"Alter database DROP Supplemental Log data;".
or if we need to disable, how can we do so?
Rest is ok. Anyways I would not be using force logging.
Droping of additional tablespace created to keep logminer tables on primary.
Removing of log_archive_dest_2 information from primary init.
I think the above should do.
Regards,
Tushar

Create table on Logical Standby Database

Dear DBAs,
here is my situation;
1. My primary database (where the tables' owner is "ICC" having a DBA) is used for insert/update transactions.
2. The logical stdby DB (dataguard structure with MAX availability) is used to generate reports, after updating some tables owned by the same user "ICC". note that these tables are excluded from the replication.
3. The developers might need to create this kind of tables to generate another kind of reports.
The issue is that when the standby apply is enabled or disabled, the user ICC is not able to create a new table, it gives ORA-01031: insufficient privileges. note that it's not practical to ask the DBA to disable the "APPLY" at any table creation.
Do you have an idea about how to resolve.
My database is 10gR2 path.10.2.0.4.0 on Windows 2003
Thank you in advance

If you stop applying log on the logical standby you can easily create a table over there. See oracle docs. The following list shows >how to re-create a table and restart SQL Apply on that table:
>
Stop SQL Apply:
SQL> ALTER DATABASE STOP LOGICAL STANDBY APPLY;
Ensure no operations are being skipped for the table in question by querying the DBA_LOGSTDBY_SKIP view:
SQL> SELECT * FROM DBA_LOGSTDBY_SKIP;
ERROR STATEMENT_OPT OWNER NAME PROC
N SCHEMA_DDL HR EMPLOYEES
N DML HR EMPLOYEES
N SCHEMA_DDL OE TEST_ORDER
N DML OE TEST_ORDER
Because you already have skip rules associated with the table that you want to re-create on the logical standby >database, you must first delete those rules. You can accomplish that by calling the DBMS_LOGSTDBY.UNSKIP >procedure. For example:
SQL> EXECUTE DBMS_LOGSTDBY.UNSKIP(stmt => 'DML', -
schema_name => 'HR', - object_name => 'EMPLOYEES');SQL> EXECUTE DBMS_LOGSTDBY.UNSKIP(stmt >=> 'SCHEMA_DDL', -
schema_name => 'HR', - object_name => 'EMPLOYEES');
Re-create the table HR.EMPLOYEES with all its data in the logical standby database by using the >DBMS_LOGSTDBY.INSTANTIATE_TABLE procedure. For example:
SQL> EXECUTE DBMS_LOGSTDBY.INSTANTIATE_TABLE(shema_name => 'HR', -
object-_name => 'EMPLOYEES', -
dblink => 'BOSTON');
Start SQL Apply:
SQL> ALTER DATABASE START LOGICAL STANDBY APPLY IMMEDIATE;Regards.

Physical Standby database Vs. Logical Standby database

I have few questions regarding capability of Logical Standby Database against Physical Standby database.
1. How efficient is Logical Standby database in terms of Physical Standby Database?? How both differ from each other and can I use Logical Standby Database for disaster Recovery?? Can It be use for recovering the failed Primary Instance?? If yes how efficient and reliable it is??
2. What are the known bugs and roadblocks for logical standby database on Oracle 10.2.0.1 on Soalris X86-64?
3.As logical standby database not going to replicate each and every schema of Primary database?? how is the change management effects to the logical standby from primary?? I mean there are some parameters and job that we create on primary how can it be transferred over to the logical standby??

1. How efficient is Logical Standby database in terms
of Physical Standby Database?? How both differ from
each other and can I use Logical Standby Database for
disaster Recovery?? Can It be use for recovering the
failed Primary Instance?? If yes how efficient and
reliable it is??I'm not sure what sort of "efficiency" you're talking about here...
Physical standby is just the old, tried and true application of archived logs to recover a database. Very solid, very old school.
Logical standby, on the other hand, is parsing the redo log, extracting logical change records, and applying them to the standby database. This obviously takes a bit more processing effort, it's newer technology, it doesn't have quite the level of support that physical standby does (i.e. certain data types are excluded), etc. You certainly can use it for failover, but it isn't quite as robust as a physical standby. Of course, this is getting better and better all the time and is definitely a focus of Oracle's development efforts.
On the other hand, logical standby systems can do things other than act as a warm standby. They can be open serving reports, for example. You can create additional structures (i.e. new materialized views) to support reporting. A physical standby is pretty much always going to be in managed recovery mode, so it cannot be queried.
2. What are the known bugs and roadblocks for logical
standby database on Oracle 10.2.0.1 on Soalris
X86-64?a) You'll want to do a Metalink search
b) If you're talking about a high-availability solution, why are you looking at a base release of the database? Why wouldn't you apply the latest patchset?
3.As logical standby database not going to replicate
each and every schema of Primary database?? how is
the change management effects to the logical standby
from primary?? I mean there are some parameters and
job that we create on primary how can it be
transferred over to the logical standby??I'm not sure I understand... Changes made to the primary generate redo. Oracle parses that redo, generates a LCR, and sends that to the standby database where that change record gets applied.
Justin

How to remove logical standby database configuration cleanly

Hello,
We are on RHL with 11.2.0.3 DB version. Due to various unknown reasons we would like to recreate logical standby database and for that purpose I would like to cleanly remove/uninstall/drop LOGICAL STANDBY DATABASE from the DATA GUARD configuration we have.
The DG setup already has 1 PHYSICAL STANDBY DATABASE which is working fine. PRIM,PHYSICAL, and LOGICAL all are on different HOSTS. Could you please guide or suggest us exact MOS Doc id regarding this? I have found one MOS Doc id which is close enough but its steps include removing dg configuration completely which I don't want. Only Logical Standby database needs to be remove cleanly so that it can be installed again properly.
We are using GRID CONTROL and DATA GUARD BROKER.
Bundle of thanks in advance.
Best Regards

Hello;
I would review this Oracle note:
How to remove a Data Guard Configuration from Primary Database (Doc ID 733794.1)
Best Regards
mseberg

How to create logical standby database without using Oracle Grid Control

Hi All,
I want to create Logical standby database on 11gr2 on RHEL 5 without using oracle Grid Control.
I already have a primary database as well as physical standby database.
What i want to create a logical standby database as well on the same machine where physical standby database is running.
So anyone of you help me out to do that
Thanks in advance

Hi,
Creating a Logical Standby Database
http://download.oracle.com/docs/cd/B19306_01/server.102/b14239/create_ls.htm#SBYDB00300
Regards,
Tom

How to create logical standby database?

Hi,
can i created logical standby database without creating physical stanby database? is it possible?
Thanks,

Hi,
Creating a Logical Standby Database
http://download.oracle.com/docs/cd/B19306_01/server.102/b14239/create_ls.htm#SBYDB00300
Regards,
Tom

Steps on Creating a Logical Standby Database

Hi,
I want to create a Logical Standby Database using 9.2.0.6. Anybody having steps of creating the same?
Regards,
Tushar

A good start from here
http://download-uk.oracle.com/docs/cd/A97630_01/server.920/a96653/createls.htm
Cheers
http://fiedizheng.blogspot.com/

Confusion regarding logical standby database

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