Standby redo log file

Hi,
From oracle document i know in the standby side the RFS process writes to Standby redo log file -> archive log and the MRP procees applys the archive logs to the standby database.
my question is ,if we dont create standby redo log file what happens?

Hello;
When redo is received by an RFS on the standby , the RFS process writes the redo data into archived redo logs or optionally to the SRL.
Standby Redo Logs is where the RFS process at your Standby database writes incoming redo, they help performance because the RFS does not have to create the Archive log file.
Standby redo logs are a component of the Data Guard setup. They should be the same size as the redo logs on the Primary.
Standby Redo Logs do not not to be multiplexed.
I would create SRL them on both the Primary and the Standby. Think of it as one database in either Standby or Primary Mode. If you have to switchover you still need them.
If you have SRL's setup and need to do either a failover or switchover it should occur faster and safer.
Best Regards
mseberg

Similar Messages

  • What is the purpose of standby redo log files

    Hi,
    What is the purpose of the standby redo log files in DR?
    what if the standby redo log files are created? or else not created?
    Please explain
    Thanks

    3.1.3 Configure a Standby Redo LogA standby redo log is required for the maximum protection and maximum availability modes and the LGWR ASYNC transport mode is recommended for all databases. Data Guard can recover and apply more redo data from a standby redo log than from archived redo log files alone.
    You should plan the standby redo log configuration and create all required log groups and group members when you create the standby database. For increased availability, consider multiplexing the standby redo log files, similar to the way that online redo log files are multiplexed.>
    Reference http://download.oracle.com/docs/cd/B19306_01/server.102/b14239/create_ps.htm#i1225703
    HTH
    Anand

  • Unassigned Status Of Standby Redo Log Files

    I created 2 standby redo log groups, and use LGWR in primary site to
    transfer redo data, all are good. But when I query the V$STANDBY_LOG
    view, I found that the status column of my both standby redo logs is UNASSIGNED".
    also sequence#
    THREAD# and all others are 0 and 0.
    Any explains.

    Thanks for the reply Sophie. I did perform log switch at my primary site but the status of standby redo log files remained unassinged. I am pasting here the message in my Alert Log file may be that can help you to diagonose the problem.
    ALTER DATABASE SET STANDBY DATABASE PROTECTED
    Tue Jul 26 15:35:18 2005
    Completed: ALTER DATABASE SET STANDBY DATABASE PROTECTED
    Tue Jul 26 15:35:22 2005
    ALTER DATABASE OPEN
    Tue Jul 26 15:35:23 2005
    LGWR: Primary database is in CLUSTER CONSISTENT mode
    LGWR: Primary database is in MAXIMUM PROTECTION mode
    LGWR: Destination LOG_ARCHIVE_DEST_1 is not serviced by LGWR
    LNS0 started with pid=18
    Tue Jul 26 15:35:28 2005
    LGWR: Error 16086 verifying archivelog destination LOG_ARCHIVE_DEST_2
    LGWR: Continuing...
    Tue Jul 26 15:35:28 2005
    Errors in file e:\oracle\admin\test\bdump\test_lgwr_1864.trc:
    ORA-16086: standby database does not contain available standby log files
    LGWR: Error 16086 disconnecting from destination LOG_ARCHIVE_DEST_2 standby host 'TESTstdb'
    LGWR: Minimum of 1 applicable standby database required
    Tue Jul 26 15:35:28 2005
    Errors in file e:\oracle\admin\test\bdump\test_lgwr_1864.trc:
    ORA-16072: a minimum of one standby database destination is required
    LGWR: terminating instance due to error 16072
    Instance terminated by LGWR, pid = 1864

  • Dataguard lost both Primary redo log and standby redo log files

    Hi,
    I am new to data guard, i came acorss a scenario where we loose both primary redo log file and standby redo log files.
    Can someone please help me understand how to recover from this situation.
    Thanks!

    >loose both primary redo log file and standby redo log files
    We have to be very clear.
    There are (set A) online redo log files  and (set B) standby redo log files at (location 1) Primary and (location 2) Standby.
    The standby redo log files, depending on the configuration, aren't strictly mandatory.  The standby can be applying redo without online redo log files present as well, depending on how it was setup.
    So, the question is  : Did you lose online redo log files at the primary ?  Didn't the primary shutdown itself then ? If so, you have to do an incomplete recovery at the primary OR switch over to the standby (which may or may not have received the last transaction, depending on how it was configured and operating)   OR restore from the standby (again, with possible loss of transactions) to the primary.
    Hemant K Chitale

  • Use of standby redo log files in primary database

    Hi All,
    What is the exact use of setting up standby redo log files in the primary database on a data guard setup?
    any good documents?

    A standby redo log is required for the maximum protection and maximum availability modes and the LGWR ASYNC transport mode is recommended for all databases. Data Guard can recover and apply more redo data from a standby redo log than from archived redo log files alone.
    You should plan the standby redo log configuration and create all required log groups and group members when you create the standby database. For increased availability, consider multiplexing the standby redo log files, similar to the way that online redo log files are multiplexed.
    refer the link,and Perform the following steps to configure the standby redo log.:-
    http://download.oracle.com/docs/cd/B19306_01/server.102/b14239/create_ps.htm#i1225703
    If the real-time apply feature is enabled, log apply services can apply redo data as it is received, without waiting for the current standby redo log file to be archived. This results in faster switchover and failover times because the standby redo log files have been applied already to the standby database by the time the failover or switchover begins.
    refer the link
    http://download.oracle.com/docs/cd/B19306_01/server.102/b14239/log_apply.htm#i1023371

  • Do I need to create new group for standby redo log files?

    I have 10 group of redo log files with 2 members for each group for my primary database , Do I need to create new group for standby redo log files for the standby database
    Group#     Members
    ==============
    1              2
    2              2
    3             2
    4             2
    5             2
    6             2
    7             2
    8             2
    9             2
    10           2
    If So, The following statment is correct? or nto
    ALTER DATABASE ADD STANDBY LOGFILE GROUP 1 ('D:\Databases\epprod\StandbyRedoLog\REDO01.LOG',D:\Databases\epprod\StandbyRedoLog\REDO01_1.LOG');
    please correct me if am doin mistake
    becuase when I issue the statment I getting error message sayin the group is already created.

    Thanks John
    I just find the answer
    Yes, it's recomeded to add new group , for instnace If I have 10 group from 1 to 10 then the standby shoudl be from 11 to 20
    Thanks I found the answer.

  • Dataguard Solution for standby redo log file groups

    Respected Experts,
    My database version is 10.2.0.1.0 and Red Hat 5 os.I want to create a standby database using RMAN.
    Can any one help me with the full steps.And i'm also confuse about number of standby redo log file members
    need to be created.
    Thanks and Regards
    Monoj Das

    My database version is 10.2.0.1.0 and Red Hat 5 os.I want to create a standby database using RMAN.To configure standby either you can use duplicate target database for standby
    or
    1) restore standby controlfile
    2) mount standby database
    3) restore database
    and configure standby paraemter then start MRP, will do.
    http://docs.oracle.com/cd/B19306_01/server.102/b14239/create_ps.htm
    Can any one help me with the full steps.And i'm also confuse about number of standby redo log file members
    need to be created.It depends which parameter you want to use, if you mention log_archive_dest_2='service ARCH ' then no need to create any standby redo log file groups,
    If you use log_archive_dest_2='service LGWR ' here transport will be in terms of redo and you need standby redo log files on standby database. Which is realtime.
    When you use LGWR, data lost will be less if in case of any online redo log file lost. which is recommended.
    HTH.

  • How do look if i have Standby Redo Log files

    How do look if i have Standby Redo Log files
    example of creating them..

    To check existence of Standby Redo Log Files:
    SQL> v$standby_log
    Name                                      Null?    Type
    ----------------------------------------- -------- ---------------------------- GROUP#                                             NUMBER
    DBID                                               VARCHAR2(40)
    THREAD#                                            NUMBER
    SEQUENCE#                                          NUMBER
    BYTES                                              NUMBER
    USED                                               NUMBER
    ARCHIVED                                           VARCHAR2(3)
    STATUS                                             VARCHAR2(10)
    FIRST_CHANGE#                                      NUMBER
    FIRST_TIME                                         DATE
    LAST_CHANGE#                                       NUMBER
    LAST_TIME                                          DATE
    SQL> select * from v$standby_log;
    no rows selected
    SQL>To Create a Standby Redo Log file:
    SQL> alter database add standby logfile group 11 ('/u01/app/test.log') size 5m;
    Database altered.
    SQL> set line 10000
    SQL> select * from v$standby_log;
        GROUP# DBID                                        THREAD#  SEQUENCE#      BYTES       USED ARC STATUS     FIRST_CHANGE# FIRST_TIM LAST_CHANGE# LAST_TIME
            11 UNASSIGNED                                        0          0    5242880        512 YES UNASSIGNED              0                      0
    SQL>and this is how you drop:
    SQL> alter database drop standby logfile group 11;
    Database altered.
    SQL> ! rm /u01/app/test.log
    SQL>Asif Momen
    http://momendba.blogspot.com
    Edited by: Asif Momen on Mar 16, 2010 1:32 PM
    Included DROP example

  • Standby Redo Log Files and Directory Structure in Standby Site

    Hi Guru's
    I just want to confirm, i know that if the Directory structure is different i need to mention these 2 parameter in pfile
    on primary site:
    DB_CONVERT_DATAFILE='standby','primary'
    LOG_CONVERT_DATAFILE='standby','primary'
    On secondary Site:
    DB_CONVERT_DATAFILE='primary','standby'
    LOG_CONVERT_DATAFILE='primary','standby'
    But i want to confirm this wheather i need to issue the complete path of the directory in both the above paramtere:
    like:
    DB_CONVERT_DATAFILE='/u01/oracle/app/oracle/oradata/standby','/u01/oracle/app/oracle/oradata/primary'
    LOG_CONVERT_DATAFILE='/u01/oracle/app/oracle/oradata/standby','/u01/oracle/app/oracle/oradata/primary'
    Second Confusion:-
    After transferring Redo Standby log files created on primary and taken to standby on the above mentioned directory structure and after restoring the backup of primary db alongwith the standby control file will not impact the physical standby redo log placed on the above mentioned location.
    Thanks in advance for your help

    Hello,
    Regarding your 1st question, you need to provide the complete path and not just the directory name.
    On the standby:
    db_file_name_convert='<Full path of the datafiles on primary server>','<full path of the datafiles to be stored on the standby server>';
    log_file_name_convert='<Full path of the redo logfiles on primary server>','<full path of the redo logfiles on the standby server>';
    Second Confusion:-
    After transferring Redo Standby log files created on primary and taken to standby on the above mentioned directory structure and after restoring the backup of primary db alongwith the standby control file will not impact the physical standby redo log placed on the above mentioned location.
    How are you creating the standby database ? Using RMAN duplicate or through the restore/recovery options ?
    You can create the standby redo logs later.
    Regards,
    Shivananda

  • Require 9i Primary and Standby redo logs files same size?

    Hi,
    We have 9.2.0.6 Oracle RAC (2 node) and configured data guard (physical standby).
    I want to increase redo log files size, but i can't this do same time primary and standby side.
    Is there a rule, primary and standby database instances have same size redo log files?
    If I increase only primary redo log files, is there any side effect? However I try this issue on test system. I increased all primary redo log files(if status='INACTIVE' drop redo log group and add redo log group, switch logfile,...)
    , but i couldn't changed standby side. So the system is work well. Is this correct solution or not? How can i increase both sides redo log files?
    Thank you for helps..

    Thank you for your helps.. I found this issue answer:
    http://download-west.oracle.com/docs/cd/B19306_01/server.102/b14239/manage_ps.htm#i1010448
    Consequently, when you add or drop an online redo log file at the primary site, it is important that you synchronize the changes in the standby database by following these steps:
    If Redo Apply is running, you must cancel Redo Apply before you can change the log files.
    If the STANDBY_FILE_MANAGEMENT initialization parameter is set to AUTO, change the value to MANUAL.
    Add or drop an online redo log file:
    To add an online redo log file, use a SQL statement such as this:
    SQL> ALTER DATABASE ADD LOGFILE '/disk1/oracle/oradata/payroll/prmy3.log' SIZE 100M;
    To drop an online redo log file, use a SQL statement such as this:
    SQL> ALTER DATABASE DROP LOGFILE '/disk1/oracle/oradata/payroll/prmy3.log';
    Repeat the statement you used in Step 3 on each standby database.
    Restore the STANDBY_FILE_MANAGEMENT initialization parameter and the Redo Apply options to their original states.
    bye..

  • Standby Redo Log Files ?

    Hi Everyone,
    Today after reading two different sources for Standby Protection Modes i found myself puzzled and stuck. One of the article from Burleson.com says 'Oracle supports the standby redo logs on a logical standby database and can now be configured in maximum data protection modes such as MAXIMUM PROTECTION ...'
    On the other hand on some of the blogs and other resources to read, i found it something opposite to what Burleson Consulting posted on their website.
    [http://4.bp.blogspot.com/-t0G_-xc8EAs/Tpvx9w2t8oI/AAAAAAAAAN4/Jw3U9s89Wtk/s1600/final.JPG|http://4.bp.blogspot.com/-t0G_-xc8EAs/Tpvx9w2t8oI/AAAAAAAAAN4/Jw3U9s89Wtk/s1600/final.JPG]
    or
    Blog from Jeff Hunter
    [http://www.idevelopment.info/data/Oracle/DBA_tips/Data_Guard/DG_3.shtml|http://www.idevelopment.info/data/Oracle/DBA_tips/Data_Guard/DG_3.shtml]
    Minimum Requirements for Data Protection Modes
         Maximum Protection      Maximum Availability      Maximum Performance
    Redo Archival Process      LGWR      LGWR      LGWR or ARCH
    Network Transmission Mode SYNC      SYNC      ASYNC when using LGWR process. Not applicable when using ARCH process.
    Disk Write Option      AFFIRM      AFFIRM      NOAFFIRM
    Standby Redo Logs Required?      Yes      Required for physical standby databases only (Standby redo logs are not supported for logical standby databases.)      Required for physical standby databases using the LGWR process.
    Database Type      Physical only      Physical and Logical      Physical and Logical
    Please help me to find true between the two.
    Or please provide any doc to read.
    Thanks
    Prashant Dixit

    Maximum Protection Maximum Availability Maximum PerformanceDepends on Business requirement, By default Performance[most of the clients]
    Redo Archival Process ? ? ?LGWR recommended in Max performance
    Network Transmission Mode ? ? ?Depends. If max performance asynchronous
    Disk Write Option ? ? ?Not clear
    Standby Redo Logs Required? ? ? ?If real time apply - YES
    Database Type ? ? ?not clear,
    Assuming physical or logical? --Depends on requirement , Preferably Physical.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           

  • Oracle standby/redo log file shipping keeps needing logs re-registering

    Hi
    We have Log File Shipping enabled and the prod system ships redo logs over to the LFS server. It's kept 24 hours behind. It usually ships the logs (and I believe automatically registers them) without issue.
    EXCEPT - it keeps complaining about missing redo log files.
    The file is usually there; but just needs registering with:
    alter database register or replace logfile '/oracle/S1P/saparch/S1Parch1_636443_654987192.dbf';
    (we found if we left out the 'or replace' it takes a very long time or even hangs)
    It then plods on and applies the next... can go for another 2 or 3... or 20... but then often gets stuck again, and you need to register the next.
    Can spend whole days on this...!!
    We did try running a script to register the next 1365 redo logs! It failed on 4, so I ran it again... it worked on those 4, but turned up 3 others it had worked with before! HUH?!? So manually did those 3 ... fine... it carried on rolling forward... but got stuck after 10 minutes again when it hit another it reckoned needed registering (we'd already done it twice!!).
    Any ideas?
    Ross

    Hi
    We have Log File Shipping enabled and the prod system ships redo logs over to the LFS server. It's kept 24 hours behind. It usually ships the logs (and I believe automatically registers them) without issue.
    EXCEPT - it keeps complaining about missing redo log files.
    The file is usually there; but just needs registering with:
    alter database register or replace logfile '/oracle/S1P/saparch/S1Parch1_636443_654987192.dbf';
    (we found if we left out the 'or replace' it takes a very long time or even hangs)
    It then plods on and applies the next... can go for another 2 or 3... or 20... but then often gets stuck again, and you need to register the next.
    Can spend whole days on this...!!
    We did try running a script to register the next 1365 redo logs! It failed on 4, so I ran it again... it worked on those 4, but turned up 3 others it had worked with before! HUH?!? So manually did those 3 ... fine... it carried on rolling forward... but got stuck after 10 minutes again when it hit another it reckoned needed registering (we'd already done it twice!!).
    Any ideas?
    Ross

  • Question on redo log files at the standby

    Oracle version: 10.2.0.5
    Platform : AIX
    We have 2 node RAC primary with 2 node RAC standby
    Primary Instance1 named as cmapcp1
    Primary Instance2 named as cmapcp2
    Standby Instance1 named as cmapcp3
    Standby Instance2 named as cmapcp4At standby side
    SQL> show parameter log_file_name_convert
    NAME                 TYPE                 VALUE
    log_file_name_conver string               cmapcp1, cmapcp3, cmapcp2, cmapcp4
    Despite the value set for log_file_name_convert, I don't see any change in names of Online and Standby redo logs at the Standby site.
    -- From primary
    SQL> select member,type from v$logfile;
    MEMBER                                             TYPE
    +CMAPCP_DATA01/cmapcp/cmapcp_log01.dbf             ONLINE
    +CMAPCP_DATA01/cmapcp/cmapcp_log02.dbf             ONLINE
    +CMAPCP_DATA01/cmapcp/cmapcp_log03.dbf             ONLINE
    +CMAPCP_DATA01/cmapcp/cmapcp_log04.dbf             ONLINE
    +CMAPCP_DATA01/cmapcp/cmapcp_log05.dbf             ONLINE
    +CMAPCP_DATA01/cmapcp/cmapcp_log06.dbf             ONLINE
    +CMAPCP_DATA01/cmapcp/cmapcp_log11.dbf             STANDBY
    +CMAPCP_DATA01/cmapcp/cmapcp_log12.dbf             STANDBY
    +CMAPCP_DATA01/cmapcp/cmapcp_log13.dbf             STANDBY
    +CMAPCP_DATA01/cmapcp/cmapcp_log14.dbf             STANDBY
    +CMAPCP_DATA01/cmapcp/cmapcp_log15.dbf             STANDBY
    +CMAPCP_DATA01/cmapcp/cmapcp_log16.dbf             STANDBY
    +CMAPCP_DATA01/cmapcp/cmapcp_log17.dbf             STANDBY
    +CMAPCP_DATA01/cmapcp/cmapcp_log18.dbf             STANDBY
    +CMAPCP_DATA01/cmapcp/cmapcp_log19.dbf             STANDBY
    +CMAPCP_DATA01/cmapcp/cmapcp_log20.dbf             STANDBY
    16 rows selected.-- From standby
    SQL> select member,type from v$logfile;
    MEMBER                                             TYPE
    +CMAPCP_DATA01/cmapcp/cmapcp_log01.dbf             ONLINE
    +CMAPCP_DATA01/cmapcp/cmapcp_log02.dbf             ONLINE
    +CMAPCP_DATA01/cmapcp/cmapcp_log03.dbf             ONLINE
    +CMAPCP_DATA01/cmapcp/cmapcp_log04.dbf             ONLINE
    +CMAPCP_DATA01/cmapcp/cmapcp_log05.dbf             ONLINE
    +CMAPCP_DATA01/cmapcp/cmapcp_log06.dbf             ONLINE
    +CMAPCP_DATA01/cmapcp/cmapcp_log11.dbf             STANDBY
    +CMAPCP_DATA01/cmapcp/cmapcp_log12.dbf             STANDBY
    +CMAPCP_DATA01/cmapcp/cmapcp_log13.dbf             STANDBY
    +CMAPCP_DATA01/cmapcp/cmapcp_log14.dbf             STANDBY
    +CMAPCP_DATA01/cmapcp/cmapcp_log15.dbf             STANDBY
    +CMAPCP_DATA01/cmapcp/cmapcp_log16.dbf             STANDBY
    +CMAPCP_DATA01/cmapcp/cmapcp_log17.dbf             STANDBY
    +CMAPCP_DATA01/cmapcp/cmapcp_log18.dbf             STANDBY
    +CMAPCP_DATA01/cmapcp/cmapcp_log19.dbf             STANDBY
    +CMAPCP_DATA01/cmapcp/cmapcp_log20.dbf             STANDBY
    16 rows selected.--- Another thing I noticed, v$log doesn't list Standby Redo Logs. This is expected behaviour , I guess
    Below is the output from Primary and Standby (it is the same)
    set linesize 200
    set pagesize 50
    col member for a50
    break on INST SKIP PAGE on GROUP# SKIP 1
    select l.thread# inst, l.group#,lf.member, lf.type
        from v$log l , v$logfile lf
        where l.group# = lf.group#
        order by 1,2 ;
          INST     GROUP# MEMBER                                             TYPE
             1          1 +CMAPCP_DATA01/cmapcp/cmapcp_log01.dbf             ONLINE
                        2 +CMAPCP_DATA01/cmapcp/cmapcp_log02.dbf             ONLINE
                        3 +CMAPCP_DATA01/cmapcp/cmapcp_log03.dbf             ONLINE
          INST     GROUP# MEMBER                                             TYPE
             2          4 +CMAPCP_DATA01/cmapcp/cmapcp_log04.dbf             ONLINE
                        5 +CMAPCP_DATA01/cmapcp/cmapcp_log05.dbf             ONLINE
                        6 +CMAPCP_DATA01/cmapcp/cmapcp_log06.dbf             ONLINE

    John_75 wrote:
    Thank you ckpt, mseberg.
    I think log_file_name_convert is set wrongly as you've mentioned. But If I don't want to any change to name of Online or standby redo log files in standby, I don't have to set log_file_name_convert at all. Right ?From Same link
    If you specify an odd number of strings (the last string has no corresponding replacement string), an error is signalled during startup. If the filename being converted matches more than one pattern in the pattern/replace string list, the first matched pattern takes effect. There is no limit on the number of pairs that you can specify in this parameter (other than the hard limit of the maximum length of multivalue parameters).

  • The file structure online redo log, archived redo log and standby redo log

    I have read some Oracle documentation for file structure and settings in Data Guard environment. But I still have some doubts. What is the best file structure or settings in Oracle 10.2.0.4 on UNIX for a data guard environment with 4 primary databases and 4 physical standby databases. Based on Oracle documents, there are 3 redo logs. They are: online redo logs, archived redo logs and standby redo logs. The basic settings are:
    1. Online redo logs --- This redo log must be on Primary database and logical standby database. But it is not necessary to be on physical standby database because physical standby is not open. It doesn't generate redo log. However, if don't set up online redo log on physical standby, when primary failover and switch standby as primary. How can standby perform without online redo logs? In my standby databases, online redo logs have been set up.
    2. Archived redo logs --- It is obviously that primary database, logical and physical standby database all need to have this log file being set up. Primary use it to archive log files and ship to standby. Standby use it to receive data from archived log and apply to database.
    3. Standby redo logs --- In the document, it says A standby redo log is similar to an online redo log, except that a standby redo log is used to store redo data received from another database. A standby redo log is required if you want to implement: The maximum protection and maximum availability levels of data protection and Real-time apply as well as Cascaded destinations. So it seems that this standby redo log only should be set up on standby database, not on primary database. Am my understanding correct? Because I review current redo log settings on my environment, I have found that Standby redo log directory and files have been set up on both primary and standby databases. I would like to get more information and education from experts. What is the best setting or structure on primary and standby database?

    FZheng:
    Thanks for your input. It is clear that we need 3 type of redo logs on both databases. You answer my question.
    But I have another one. In oracle ducument, it says If you have configured a standby redo log on one or more standby databases in the configuration, ensure the size of the current standby redo log file on each standby database exactly matches the size of the current online redo log file on the primary database. It says: At log switch time, if there are no available standby redo log files that match the size of the new current online redo log file on the primary database. The primary database will shut down
    My current one data gurard envirnment setting is: On primary DB, online redo log group size is 512M and standby redo log group size is 500M. On the standby DB, online redo log group size is 500M and standby redo log group size is 750M.
    This was setup by someone I don't know. Is this setting OK? or I should change Standby Redo Log on standby DB to 512M to exactly meatch with redo log size on primary?
    Edited by: 853153 on Jun 22, 2011 9:42 AM

  • Logical Standby 'CURRENT' log files

    I have an issue with a Logical Standby implementation where although everything in the Grid Control 'Data Guard' page is Normal, when I view Log File Details I have 62 files listed with a status of 'Committed Transactions Applied'.
    The oldest (2489) of these files is over 2 days old and the newest (2549) is 1 day old. The most recent applied log is 2564 (current log is 2565).
    As for the actual APPLIED_SCN in the standby, it's greater than the highest NEXT_CHANGE# for newest logfile 2549. The READ_SCN is less than the NEXT_CHANGE# of the oldest log (2489) appearing in the the list of files - which is why all these log files appear on this list.
    I am confused why the READ_SCN is not advancing. The documentation states that once the NEXT_CHANGE# of a logfile falls below READ_SCN the information in those logs has been applied or 'persistently stored in the database'.
    Is it possible that there is a transaction that spans all these log files? More recent logfiles have dropped off the list and have been applied or 'persistently stored'.
    Basically I'm unsure how to proceed and clean up this list of files and ensure that everything has been applied.
    Regards
    Graeme King

    Thank you Larry. I have actually already reviewed this document. We are not getting the error they list for long running transactions though.
    I wonder if it is related to the RMAN restore we did where I restored the whole standby database while the standby redo log files were not obviously restored and therefore were 'newer' than the restored database?
    After I restored I did see lots trace files with this message:
    ORA-00314: log 5 of thread 1, expected sequence# 2390 doesn't match 2428
    ORA-00312: online log 5 thread 1: 'F:\ORACLE\PRODUCT\10.2.0\PR0D_SRL0.F'
    ORA-00314: log 5 of thread 1, expected sequence# 2390 doesn't match 2428
    ORA-00312: online log 5 thread 1: 'F:\ORACLE\PRODUCT\10.2.0\PR0D_SRL0.F'
    I just stopped and restarted the SQL apply and sure enough it was cycled through all the log files in the list from the (READ_SCN onwards) but they are still in the list. Also there is very little activity on this non-production database.
    regards
    Graeme

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