Question: How Do I Recover Lost Redo Log Files?

How do I manually use redo logs

To apply the archived redo logs in the archive gapStart up and mount the standby database (if it is not already mounted).

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Recover the database using the AUTOMATIC option: …

Cancel recovery after the Oracle database server has applied the available logs, by executing the following statement (or typing CTRL+C):.

What are the archived redo logs used for

Archived redo logs are used to recover a database or update a standby database. Before you restore, you must locate the file. When you locate the files, ensure that the database is in the Open state.

How do you recover from the loss of datafile if the DB is running in Noarchivelog mode

To recover from loss of an active online redo log group in NOARCHIVELOG mode:If the media failure is temporary, correct the problem so that Oracle can reuse the group when required.Restore the database from a whole database backup using an operating system utility. … Mount the database:More items…

How do you know if a redo log is corrupted

Step 1: Check the status of your redo log files. Step 2: Corrupt the redo log member of the inactive group and for this practical only choose the group which has only member in it. You will be able to see the actual error in the alert log document(Please scroll above for the information about alert log document.)

How do I know the size of my redo log

Find redo log members / redo log file size / redo log statusFind redo log file members. … To find redo log file size. … Combined view of both v$logfile & v$log.Aug 22, 2016

How do I restore a redo log file

To restore archived redo logs: If the database is open, shut it down and then mount it: shutdown immediate; startup mount; Perform the following operations within your run command: If desired, specify the new location for the restored archived redo logs using set archivelog destination.

How do I find the current redo log file

The V$LOGFILE view can be used to find the datafiles for the redo logs.

How do you open database when lost group current redo log

how to open database when lost a group current redo log shutdown. delete a group current redo logs which not mutiplexing and have no backe up.startup open force. error message as following. … SQL> shutdown; ORA-24324: service handle not initialized. … SQL> QUIT; SQL> connect / as sysdba. Connected to an idle instance. … SQL> select * from v$log;Jul 25, 2020

What if redo log file was corrupted

A redo log file might become corrupted while the database is open, and ultimately stop database activity because archiving cannot continue. In this situation the ALTER DATABASE CLEAR LOGFILE statement can be used to reinitialize the file without shutting down the database.

What is online redo log files

The most crucial structure for recovery operations is the online redo log, which consists of two or more preallocated files that store all changes made to the database as they occur. Every instance of an Oracle database has an associated online redo log to protect the database in case of an instance failure.

What is the difference between archive log and redo log

Archive logs are archived redo(online) log files. In redo log files are all changes that happened to your data. If your database is in archivelog mode, than redo logs can’t be overwritten, they are archived in some other location when they are full. Redo and archive logs are used in various database recovery scenarios.

How do you check for redo log multiplex

To multiplex the redo log: Sql> select group#, member from v$logfile order by group#, member; The above query helps to find out the existing groups and members’ information. For example, if your existing member filename is redo01.

Can we delete redo log files

It is permissible to drop redo log files so that a multiplexed redo log becomes temporarily asymmetric. For example, if you use duplexed groups of redo log files, you can drop one member of one group, even though all other groups have two members each.

How do I get rid of standby redo logs

How to drop the standby redo logsEnviroment.SET STANDBY_FILE_MANAGEMENT=’MANUAL’Drop SRL On Standby.SET STANDBY_FILE_MANAGEMENT=’AUTO’Enable MRP.Enviroment. … SET STANDBY_FILE_MANAGEMENT=’MANUAL’ … Drop SRL On Standby.More items…

How do I restore a redo log in Oracle

1. Run the following code to check to see what log is currently in use. 3. Drop and recreate logfile group 1….Drop and recreate logfile group 1.sqlplus / as sysdba.SQL> alter database drop logfile group 1;SQL> alter database add logfile group 1 (‘+REDO01′,’+REDO02’) size 1G;

How do I check redo logs

When testing for redo log usage, start the job by performing a redo log switch (alter system switch logfile), so you start with a fresh redo log. Then you simply measure the number of archived redo logs generated, plus the remaining space in the current redo log.

How do you calculate redo log

I discovered that I have 15 groups of 2 GB, so the redo log group size is 30 GB. Oracle says that “In general we recommend adding an additional 30% on top of the peak rate”, so that would mean I am expected to have 245mb/s*1.3 = 318.5 MB/S.

What is different about V Datafile and Dba_data_files

Can someone please explain to me what is the difference between dba_data_files and v$datafile views? Both have the same number of records, the only differences I see is that v$datafile view has more fields and some fields are different (v$datafile does not have user-bytes fiels.