Oracle 11g OCP Notes (14)--database backup and recovery configuration

1. Understanding Backup and Recovery issues

Three indicators related to backup recovery are: MTBF average trouble-free time

MTTR mean failure recovery time.

Data loss: How much to lose the book data.

There are three advanced options for Oracle RAC Steam and DG that have an impact on performance (good bad)

2. Type of failure

1) Statement failure: DML statements are rolled back, other DML statements are not affected, and are not committed.

Use the statement Alter session enable Resumable to pause the use of tablespace problems. The parameter resumable _timeout provides a time-out configuration for the entire instance.

2) User Process failure

The Pmon process is processed on a regular basis.

3) network failure:

may be monitoring, network card, routing and other issues, the DBA is aware of configuration monitoring.

4) User error:

The following solutions can be used to prevent user errors: 1, Flashback query, flashback Delete, flashback database, and incomplete reply.

Note that commit is known within the DDL, and the DDL commits the previous thing.

5) Media failure

Use multiplexing technology to back up control files, log files,

Back up three large files regularly.

Use RM-RF commands with caution.

Use RAID or ASM to ensure data redundancy.

6) Instance failure

Power off or shut Abort command.  No DBA intervention is required to roll back and roll before the session. Smon process.

3. Instance Recovery

1) Instance recovery mechanism: Execute the startup command, Smon will roll back in the rollback.

Tip: The startup command can prevent data loss.

2) The database is not likely to receive corruption. View as an example.

3) Configure instance recovery. 1 understand the concept of checkpoints. 2 Setting Parameters Fast_start_mttr_target parameter (9i introduction)

4) Mttr Auto Adjust default is 0, the maximum is 3,600 seconds,

V$instance_recovery

Recovery_estimated_ios If the instance crashes, the number of reads and writes performed on the data file in order to recover

Actual--redo_blocks

Estimated_mttr If it fails, the time it takes to open the database.

Tartget_mttr the settings of the Fast_start_mttr_target.

Waites_mttr In addition to normal read and write, dbwn execution times.

The number of DBWN initiated by the Writes_autotune Auto-tuning mechanism.

If you set Fast_start_mttr_target to a value other than zero, the checkpoint auto-adjustment will start.

5) Checkpoint

Normal shutdown, and then boot does not require instance recovery. A full checkpoint will occur.

Checkpoints can also occur in the following situations:

① table Space Offline--all blocks of the table space

② data file offline-all blocks of the data file

③ Delete space,---make all the blocks of space?????????????????? Extend, how to delete?

④truncate table,--all data of the table

⑤ all data in the tablespace by placing the tablespace in Backup mode.

Alter system checkpoint manually perform checkpoints.

--------------------------

4 Prepare for recoverability of the database.

1) Protect control files

Multiplexing, up to 8, one corruption, immediate downtime

Off--Copy, boot to nomount status--Modify parameter-->startup force.??

Close data--Create pfile, modify Pfile. Create SPFile---> Copy control Files--Start the database-----that should be okay.

2) protect redo log files.

Multiplexing, a member corruption, can continue to work.

Select group#, sequence#, member,startus from V$log;

Select group#, Startus, member from V$logfile;

ALTER SYSTEM switch logfile

Add member ALTER DATABASE add logfile member ' D:\XXX.log ' to group 1;

3) archive mode and archive process

The mode of the Jin gear,

The archive process is started automatically.

Modified into archive mode.

1 Creating a Directory

2, alter system set log_archive_dest_1= ' Location=/arch ' scope=spfile.

Alter system set log_archive_format= ' Arch_d_r_s_t.arch ' scpoe=spfile

3 Shutting down the database (not abort)

4startup Mount

5. Alter DATABASE Archivelog

6. Alter DATABASE Open

7, check the update.

Select Log_mode from V$database.

Select Archiver from V$instance

4) Protect archive files

Log_archive_desc_n Multiplexing,

The arch process will hang if there is a problem with the database.

----------------------------------------------------------------------------

5. Configure the Flashback recovery area

1) Recover files

The multiplexed copy of the control file-----------Permanent

Redo Multiplexing Replicas----------------Permanent

Arch file

Rman Backup

Rman Copy

Automatic backup of control files

Flash back to the log.

2) configuration

Db_recovery_file_dest-----Path is dynamic, and if modified, the previous path is known.

Db_recovery_file_dest_size----Size (first set/)

Db_recovery_file_dest dynamic, if modified, the previous path is also known. The following views all contain Is_recovery_dest_file columns.

V$controlfile

V$logfile

V$backup_pace

V$archive_log

Use of the flashback reply area.

V$flash_recovery_area_usage query space using cleanup.

Oracle 11g OCP Notes (14)--database backup and recovery configuration