Introduction to Oracle instance recovery and flashback

Introduction to Oracle instance recovery and flashback

Instance recovery phase:
1. data files are not synchronized

2. Roll Forward (redo)
3. submitted and unsubmitted data in the file

4. Open the database

5. Roll Back (Restore undo)

6. submit data in the file
Optimize instance recovery: (accelerate dirty Data Writing)
Use MTTR
Fast_start_mttr_target (do not set/increase system burden)
Db_writer_pricesses (DBWn process)

Flashback;
The location is specified by the DB_RECOVERY_FILE_DEST parameter and the size is specified by the DB_RECOVERY_FILE_DEST_SIZE parameter. This parameter can be used to store backup, archived logs, flash logs, image control files, and image redo logs and automatically manage them according to the retention policy
Flash query: flashback query
Flash back transaction query:
Flash back VERSION Query:
Flash Back table deletion:
Flash back database:
Flash back archive: 11 GB New Features

Flash recovery zone: the default location of all recovery-related files, which simplifies the management of files required for restoration and recovery.
Permanent file: Control File multiplexing copy
Online redo log file multiplexing copies
Temporary Files: Archived logs, rman backups, and copies
Automatic Backup of Control Files
Flash Back log files,
Except for the flash log, other files can be redirected.

Archive log list;
-- Check whether the archive is enabled
Select log_mode from v $ database;
-- Whether the database is archived

The is_recovery_dest_file of the data dictionary shows whether the data is stored in the Flash recovery zone.

V $ controlfile, v $ logfile, v $ archived_log
V $ recovery_file_dest
-----------------------------------------------------

Select GROUP #, BYTES/1024/1024 size_m, MEMBERS, STATUS from v $ log;
-- View a log Group
Alter system switch logfile;
-- Switch logs
Select GROUP #, STATUS, TYPE, MEMBER, IS_RECOVERY_DEST_FILE from v $ logfile;
-- View information in v $ logfile

Instance recovery: instance recovery
Crash recovery: crash recovery

Oracle 11g Flashback Data Archive (flash back Data archiving)

Oracle Flashback flash back Mechanism

Oracle Flashback database

Flashback table quick recovery of accidentally deleted data

Oracle backup recovery: Flashback flash back