DB restore Archives not lost mode redo log file... restore from controlfile tr

Similar Questions

• ORA-38754: FLASHBACK DATABASE not started; required redo log is not available

  Hello

  I am getting below error when executing the activities of flashback. Currently we have backups, so when I tried the command flashback in RMAN my question solved.

  But if I want to do the same thing using SQLPLUS what steps should I take?

  ERROR:

  ORA-38754: FLASHBACK DATABASE not started; required redo log is not available

  ORA-38762: redo logs needed for SNA to SNA 20062842936 20062842926

  ORA-38761: redo log sequence 4 in thread 2, 65 incarnation cannot

  consulted

  DATABASE:11.2.0.3.0 (UAT)

  RMAN will automatically restore logs archived redo required for the operation of blowback when they are not present on the drive, while (as meyssoun said) when using sqlplus required archived redo logs must be available on the disc.

  Concerning

  AJ

• Recreate the Member lost/damaged redo log in a group

  DB version: 11.2.0.4

  OS: Oracle Linux 6.5

  In this particular PB we have multiplexes recovery logs (2 members from each group of redo).

  If one member of a group of Redo log is corrupted then, regardless of whether the Member belonged to the Group that is CURRENT, ACTIVE or INACTIVE, can we just let GO and CREATE the file journal lost this group member by following the steps below?

  -Find the corrupted Member

  SELECT GROUP #, STATUS, MEMBER OF V$ LOGFILE WHERE STATUS = 'INVALID ';

  1 back UP the DB

  2. CHANGE THE SYSTEM CHECKPOINT;

  3 ALTER DATABASE CLEAR LOGFILE GROUP 3;  - , This step should not be executed. Right?

  4. ALTER DATABASE DROP LOGFILE MEMBER ' / oracle/oradata/wms/redo02.log';

  (Apparently, this removes not the logfile at the OS level, only the control file is updated in the DB)

  5 ALTER DATABASE ADD LOGFILE MEMBER ' / oracle/oradata/wms/redo02b.log' to GROUP 3.

  When I googled for steps, I found the table below in the official documentation of the Oracle. This table is applicable only if the ENTIRE REDO LOG disappeared.

  http://docs.Oracle.com/CD/E25054_01/backup.1111/e10642/osadvsce.htm#CACFJDBG

  I want just the steps if only 1 member of a multiplex group is lost/damaged.

  3. ALTER DATABASE CLEAR LOGFILE GROUP 3;  -This step should not be executed. Right?

  Yes. It's true. You can refer to the section 'Recovery after losing a member of the a multiplex online Redo Log group' under recovery after the loss of online redo log files: scenarios

  HTH

  -Jonathan Rolland

• What is the role of the archived in an incremental backup redo log files?

  I want to know, to which RMAN reads what block of data is changed after the last incremental backup.
  and what is the role of the archived in an incremental backup redo log files?
  
  Please guide.

  Hello

  First Querstion response->
  Each block of data in a data file contains a system change number (SCN), which is the SCN of the last change to the block. During an incremental backup, RMAN reads the RCS of each block of data in the input file and compares at the checkpoint SCN of the incremental backup from parent. If the RCS in the block of input data is greater than or equal to checkpoint SCN of the parent, then RMAN copies the block.

  2 - the archived redolog files are required for the restoration of the online of rman incremental backup in a consistent state.

  Thank you & best regards
  Rahul Sharma

• That redo log files waiting?

  Hello Experts,

  I read articles on the log redo and undo segment files. I was wondering something very simple. That redo log files waiting in there? It stores the sql statements?

  Lets say that my update statement to modify 800 blocks of data. A unique single update statement can modify different data 800 right blocks? Yes, it may be true. I think that these data blocks can not hold buffers to the log to roll forward, right? I mean I know exactly what to do redo log buffer and redo log file. And I know that the task of backgrounding LGWR. But, I wonder if she she holds the data blocks? It is not supposed to hold data like cache buffer blocks, right?

  My second question is, rollback isn't effect to restore the newspaper to the right buffer? Because it does not need log buffer for effect do it again. Conversely, the restoration; statement is included in the restore log buffer by progression when someone isse, am I right?

  As far as I know, rollback interact directly with UNDO TABLESPACE?

  I hope that I have to express myself clearly.

  Thanks in advance.

  Here's my question:

  My second question is, rollback isn't effect to restore the newspaper to the right buffer? Because it does not need log buffer for effect do it again. Conversely, the restoration; statement is included in the restore log buffer by progression when someone isse, am I right?

  As far as I know, rollback interact directly with UNDO TABLESPACE?

  Yes, where else would the undo data come from? Undo tablespace contains the Undo segments that contain the Undo data required for the restoration of your transaction.

  I can say that rollback does not alter the data of the log buffer rede to the past. In other words, change vectors will be remain the same before restoration. Conversely, rollback command is also recorded in the log file of restoration by progression. As the name, all orders are saved in the REDO LOGS.

  I hope that I am wrong so far?

  Not sure why you even the buffer log roll forward for Rollback? This is the reason why I asked you it was for, where occurs the dose the cancellation? And the answer for this is that it happens in the buffer cache. Before you worry about the drivers of change, you must understand that it is not serious what contains where as long as there is no transaction recorded in the operating of the Undo segment table. If the operating table indicates that the transaction is longer there, there must be a cancellation of the transaction. Vectors of change are saved in the file log roll forward, while the restore happens on blocks of data stored in the file "data" undo blocks stored in the undo file "data".

  At the same time I read an article about redo and undo. In this article process transaction is explained. Here is the link http://pavandba.files.wordpress.com/2009/11/undo_redo1.pdf

  I found some interesting information in this article as follows.

  It is worth noting that during the restore process, recovery logs never participate. The only time where redo logs are read is retrieving and archiving. This is the concept of tuning key: redo logs are written on. Oracle does not read during normal processing. As long as you have sufficient devices so that when the ARC is reading a file, LGWR's writing to a different device, then there no contention for redo logs.

  If redo logs are never involved in the restoration process, how is it Oracle will then know the order of the transaction? As far as I know it is only written in redo logs.

  I have thoughts very amazed to Aman.

  Why you ask?

  Now, before giving a response, I say two things. One, I know Pavan and he is a regular contributor to this forum and on several other forums Facebook and two, with all due respect to him, a little advice for you, when you try to understand a concept, to stick to the Oracle documentation and do not read and merge articles/blog-posts from the web. Everone, which publishes on the web, has their own way to express things and many times, the context of the writing makes it more confusing things. Maybe we can erase the doubts that you can get after reading the various search results on the web.

  Redo logs used for the restoration, not to restore. The reason is the redo log files are applied in sequential order, and this is not the case when we look for the restoration. A restore is required to do for a few blocks away. Basically, what happens in a restoration, is that the records of cancellation required for a block of data are sought in the reverse order of their creation. The entry of the transaction is in the slot ITL of the block of data that point to the necessary undo bytes Address (UBA) using which oracle also knows what that undo the blocks would be necessary for the restoration of your transaction. As soon as the blocks of data will be cancelled, the ITL slots would be cleared as well.

  In addition, you must remember, until the transaction is not qualified as finished, using either a commit or a rollback, the cancellation of this data would remain intact. The reason for this is that oracle would ensure that undo data would be available to make the cancellation of the transaction. The reason why Undo data are also recorded in the journals of recovery is to ensure that in the event of the loss of the cancellation of the data file, retrieving them would be possible. Because it would also require changes that's happened on the blocks cancel, restore the vectors change associated with blocks of cancellation are also saved in the buffer log roll forward and, in the redo log files.

  HTH

  Aman...

• bottleneck during the passage of the redo log files.

  Hi all
  
  I'm using Oracle 11.2.0.3.
  
  The enforcement team has indicated that they are facing slow at some point.
  
  I followed the database and I found that at some passage of redo log files (not always), I am facing a slow at the application level.
  
  I have 2 son since my database is CARS, each thread has 3 groups of multiplexed redo logs the FIU, with size of 300 MB each.
  
  Is it possible to optimize the switch of the redo log files? knowing that my database is running in ARCHIVELOG mode.
  
  Kind regards

  Hello

  Yes, Oracle recommends 1 validation by 30 calls from users or less. Of course, every database is different, so this rule cannot be taken too literally, but in your case, this rule seems to apply. In any case State, 900 undertakes seconds it looks like a very large number and the need for a high number of transactions should be questioned. You should talk to your analysts/application management/enterprise architect if warranted - that is to say if the application does in fact almost 2 000 business transactions per second.

  What about DB CPU: here is a link to a blog that I wrote on this subject, it should help to better understand this number:

  http://Savvinov.com/2012/04/06/AWR-reports-interpreting-CPU-usage/

  But briefly: DB processor isn't a real event, it is simply an indication that the sessions are on CPU (or waiting for CPU) rather than wait on i/o requests or events in the database. It is not necessarily a bad thing, because the database must perform tasks and he cannot do without loading the CPU. It may indicate a problem in two cases: when the CPU usage is close to the limit of the host (OS stats section indicates that you are very far from there) or when the CPU is a % of DB time - in the latter case, this could mean that you are making too many logical reads due to inefficient plans or analysis too. In any case, this does not apply to you, because 20 percent is not very high a number.

  Other items in the list of the top 5 deserve attention, too - gc buffer busy acquire, gc current block busy, enq: TX - line lock conflict.

  To summarize, your database under a lot of stress - whether it is the legitimate workload, and if this is the case, you may need to upgrade your hardware later. There is chance that it isn't - for example a high number of runs may indicate that rather than to bulk operations database code using PL/SQL loops, which is a big performance killer. Check "Top SQL by executions" about whether or not this is the case.

  Good luck!

  Best regards
  Nikolai

• new with OMF online redo log files

  Hi all
  
  I'm using Oracle 11 g 2, I created my DB using Oracle managed (OMF) files.
  
  I wanted to re size my recovery connects so I went in an old redo logs fall and create a new.
  
  That was how my redo logs resembles. It was created by the creation of the DB with OMF format:

  .../app/oradata/ORCL11/onlinelog/o1_mf_1_6pfncw81_.log
  .../app/flash_recovery_area/ORCL11/onlinelog/o1_mf_1_6pfncx5z_.log
  .../app/oradata/ORCL11/onlinelog/o1_mf_2_6pfncxps_.log
  .../app/flash_recovery_area/ORCL11/onlinelog/o1_mf_2_6pfncz1v_.log
  .../app/oradata/ORCL11/onlinelog/o1_mf_3_6pfnczhd_.log
  .../app/flash_recovery_area/ORCL11/onlinelog/o1_mf_3_6pfnd0vw_.log

  using the script I created new below redo logs

  alter database add logfile group 1 (
  '.../app/oradata/ORCL11/onlinelog/redo1.log',  
  '.../app/flash_recovery_area/ORCL11/onlinelog/redo1.log') size 76m reuse;

  .........
  and I added the new redo log group
  

  alter database add logfile group 4 (
  '.../app/oradata/ORCL11/onlinelog/redo4.log',  
  '.../app/flash_recovery_area/ORCL11/onlinelog/redo4.log') size 76m reuse;

  I was not able to create the recovery logs, where is the name of the redo log file: o1_mf_1_6pfncw81_.log, since this is the format OMF.
  
  My question by creating my recovery connects the way does it have an impact? on the archiving of newspapers of recovery? any impact on the database for now, this isn't OMF?
  
  How can I create my redo logs with OMF format?
  
  Kind regards

  try: -.
  alter database add logfile Group 4;

  for example; -.

  SQL> alter database add logfile group 4;
  
  Database altered.
  
  SQL> select member from v$Logfile;
  
  MEMBER
  --------------------------------------------------------------------------------
  /home/u01/app/oracle/oradata/dbtest/redo03.log
  /home/u01/app/oracle/oradata/dbtest/redo02.log
  /home/u01/app/oracle/oradata/dbtest/redo01.log
  /home/u01/app/oracle/flash_recovery_area/DBTEST/onlinelog/o1_mf_4_75nmw33l_.log
  
  SQL> alter database add logfile group 5 size 100m;
  
  Database altered.
  
  SQL> select member from v$logfile;
  
  MEMBER
  --------------------------------------------------------------------------------
  /home/u01/app/oracle/oradata/dbtest/redo03.log
  /home/u01/app/oracle/oradata/dbtest/redo02.log
  /home/u01/app/oracle/oradata/dbtest/redo01.log
  /home/u01/app/oracle/flash_recovery_area/DBTEST/onlinelog/o1_mf_4_75nmw33l_.log
  /home/u01/app/oracle/flash_recovery_area/DBTEST/onlinelog/o1_mf_5_75nmyvjg_.log
  

  Published by: rajeysh on August 28, 2011 20:00

• SIZE OF THE REDO LOG FILE

  
  Hello

  I got an error message when I add me new group. log files I searched and found the answer on the form. Ago 4 M minimum size of 11 g R2 log file size.

  My question is why a log file size depends on DB_BLOCK_SIZE? This parameter is set to the component structures of memory that create an instance when a log file is an operating system file that depend on the version of the OS not DB_BLOCK_SIZE.

  Thank you.

  
  SQL > alter database add logfile group 4 'c:\app\asif\oradata\employee\redo04.log' size 1 m;
  alter database add logfile group 4 'c:\app\asif\oradata\employee\redo04.log' size 1 m
  *
  ERROR on line 1:
  ORA-00336: 2048 blocks the size of the log file is minimum lower than 8192 blocks

  
  SQL > show parameter db_block_size

  VALUE OF TYPE NAME
  ------------------------------------ ----------- ------------------------------
  Whole DB_BLOCK_SIZE 8192
  SQL >

  You are assuming that the redo log block size is the same as the database block size. This is not correct.

  The error indicates that 8192 is the minimum number of blocks of a redo log file. The documentation states that the minimum size is 4 M. For example, you can deduct your redo log block size is 512 bytes.

  Here's some more information about the size of redo log, the documentation block.

  Unlike the database block size, which can always be between 2 K and 32 K, redo log default files to a block size that is equal to the size of physical sector of the disk. Historically, it is usually 512 bytes (512 b).

  Some new large disks offer 4K sizes byte (4K) to increase sector efficiency improved format and ECC capabilities. Most of the Oracle database platforms are able to detect this bigger sector size. The database then automatically creates files redo log with a block size of 4 K of these discs.

• What is the purpose of waiting for redo log files

  Hello
  
  What is the purpose of the log files waiting for redo in the Dr?
  
  What happens if the standby redo log files are created? or else is not created?
  
  Please explain
  
  Thank you

  Re: what is the difference between onlinelog and standbylog

  I mentioned the goal of the eve of the redo log in RD files in above thread.

  Concerning
  Girish Sharma

• How to find the configuration state of REDO logs files?

  I'm trying to move the redo log files.
  Before that, I want to know if it is set as a duplex or any other configuration.
  
  How to find the REDO log configurations.
  
  Oracle 10g R2
  
  Thank you
  Smith

  Example:

  Not in duplex redo log - if the number of members is 1, it is not duplex:

  SQL> select group#, members from v$log;
  
      GROUP#    MEMBERS
  ---------- ----------
           1          1
           2          1
           3          1
  
  SQL> select group#, member from v$logfile;
  
      GROUP# MEMBER
  ---------- --------------------------------------------------
           1 /u01/app/oracle/oradata/db1/redo01.log
           2 /u01/app/oracle/oradata/db1/redo02.log
           3 /u01/app/oracle/oradata/db1/redo03.log
  
  SQL> alter database add logfile member '/u01/app/oracle/oradata/db1/redo01_2.log' to group 1;
  
  Database altered.
  
  SQL> alter database add logfile member '/u01/app/oracle/oradata/db1/redo02_2.log' to group 2;
  
  Database altered.
  
  SQL> alter database add logfile member '/u01/app/oracle/oradata/db1/redo03_2.log' to group 3;
  
  Database altered.
  

  Duplex redolog

  SQL> select group#, members from v$log;
  
      GROUP#    MEMBERS
  ---------- ----------
           1          2
           2          2
           3          2
  
  SQL> select group#, member from v$logfile;
  
      GROUP# MEMBER
  ---------- --------------------------------------------------
           1 /u01/app/oracle/oradata/db1/redo01.log
           2 /u01/app/oracle/oradata/db1/redo02.log
           3 /u01/app/oracle/oradata/db1/redo03.log
           1 /u01/app/oracle/oradata/db1/redo01_2.log
           2 /u01/app/oracle/oradata/db1/redo02_2.log
           3 /u01/app/oracle/oradata/db1/redo03_2.log
  

• How to change the location of the redo log files... ?

  I want all my redo log files to be created in \u10 instead of/U01 current?
  How to do? NOARCHIVELOG mode database on Oracle 10 g R2.
  Thank you
  Smirh

  user517525 wrote:
  Thank you
  Smirh

  [Move Redo Log members | http://download.oracle.com/docs/cd/B19306_01/server.102/b14231/onlineredo.htm#sthref951]

• Could not open INSTALL. LOG file

  I tried to remove some programs from my xp, but some will not remove. They give me this message: could not open INSTALL. LOG file. Can anyone help.

  I tried to remove some programs from my xp, but some will not remove. They give me this message: could not open INSTALL. LOG file. Can anyone help.

  Download, install and use the trial version of Recuva Uninstaller.  With she and her advanced (more aggressive) scans, you should be able to get rid of the applications in question.  You can remove it later if so desired (or buy it and keep it around for the future) - up to you.  I just suggest because he did a great job on these things.

• Redo log entries to the online redo log files

  Hello

  I'm a little confused about the redo log entries.

  I learned that LGWR writes redo log entries in the SGA, in redo log files in the following situation:

  -3 seconds after the last validation

  -redo log buffer has 1 MB

  -redo log buffer data 1/3

  When I take a transaction and if I change the wrong data, I have to cancel this transaction BUT the right now,

  What happens if the LGWR writes redo log disk entries?

  Is the bad transaction committed at all times?

  2791011 wrote:

  Hello

  I'm a little confused about the redo log entries.

  I learned that LGWR writes redo log entries in the SGA, in redo log files in the following situation:

  -3 seconds after the last validation

  -redo log buffer has 1 MB

  -redo log buffer data 1/3

  When I take a transaction and if I change erroneous data, I have to cancel this transaction at this time, BUT

  What happens if the LGWR writes redo log disk entries?

  Is the bad transaction committed at all times?

  DML changes are "permanent" after that VALIDATION is issued.

  When any COMMIT is issued, then changes can be undone.

• I have to create the new group for waiting for redo log files?

  I have 10 group of files redo log with 2 members of each group for my primary database, I need to create new group for redo log files for the database of relief pending

  Group # members

  ==============

  1              2

  2              2

  3             2

  4             2

  5             2

  6             2

  7             2

  8             2

  9             2

  2 of 10

  If so, the following statement 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 wrong

  because when I run the statement I have error message saying: the group is already created.

  Thanks John

  I just found the answer

  Yes, it of recomeded to add the new group, for instnace if I have 10 group of 1 to 10, then the wait should be from 11 to 20

  Thanks I found the answer.

• number of redo log files

  Hello
  What is the best practice to determine the number of redo log files,
  3 groups with 1 member of each or,
  2 groups with 2 members of each?
  which is optimal and recommended?
  Thank you very much

  Agree with Deepak.

  http://download.Oracle.com/docs/CD/B19306_01/server.102/b14231/onlineredo.htm#i1306224

  Read the link. It will help you.

  Concerning
  Asif Kabir