See if the Oracle database is archive mode [1] 1.select name,log_mode from v$database; name log_mode ----------------- ------------------------- QUERY noarchivelog 2. Using the Archive Log LIST command Database log mode No Archive Mo de Automatic Archival disabled Archive destination/data/oracle/product/10.2.0/db_1//dbs/arch Oldest online log sequence 739 current log sequence 741 what is Oracle Archive mode Oracle database has an online redo log that records changes made to the database, such as inserting , delete, update data, and so on, these actions are recorded in the online redo log. A generic database must have at least 2 online redo log groups. When an online redo log group is written full, a log switch occurs, the online redo log Group 2 becomes the currently used log, when the online redo log Group 2 is full, the log switch, to write online redo log Group 1, so repeated. If the database is in non-archive mode, the online log is discarded when it switches. In archive mode, when a log switch occurs, the log that is toggled is archived. For example, in the current use of online redo log 1, when 1 is full, a log switch occurs, start to write online redo log 2, the contents of online redo log 1 will be copied to another specified directory. This directory is called the Archive directory, and the copied files are called archive redo logs. The database can be used for a catastrophic recovery only when it is running in archive mode. 1. Differences between archived and non-archived log Modes Non-archive mode can only be cold backed up, and only a full backup can be done when recovering. Data not recovered during the most recent full backup to system error . archive mode can do hot backups, and can do incremental backups, Can do partial recovery . with archive LOG LIST to see whether the current mode state is archive mode or non-archive mode . The archiving mode of the configuration database 1. Change non-returnFile mode to archive mode: 1) sql> conn/as sysdba (database connected as DBA) 2) sql> shutdown immediate; (Close database Now) 3) sql> startup mount (launch instance and load database but not open) 4) sql> ALTER DATABASE archivelog; (change databases to archive mode) 5) sql> ALTER DATABASE open; (Open database) 6) sql> alter system archive log start; (Enable auto-archive) 7) sql> exit Make a full backup because the backup log generated in non-archived log mode is not available for the archive mode. This step is not very important! 2. Change the archive mode to non-archive mode: 1) Sql>shutdown normal/immediate; 2) sql>startup mount; 3) sql>alter DATABASE NOARCHIVELOG;& nbsp 4) Sql>alter DATABASE open; 3. Enable AutoArchive: log_archive_start=true archive mode, the log file group is not allowed to be overwritten (rewritten), after the journal file is full, If manual archiving is not performed, then the system hangs, knowing that the archive is complete until . is read only and cannot be written . shut down and restart the archive log process during run time sql>archive log stop sql> ARCHIVE log start 4. Manual archive: log_archive_start=false Archive Current log file Sql>alter SYSTEM ARCHIVE log current;&n Bsp Log files with the archive sequence number 052 Sql>alter SYSTEM ARCHIVE log SEQUENCE 052; Archive all log files Sql>alteR SYSTEM ARCHIVE Log all; Change archive log target Sql>alter SYSTEM ARCHIVE log current to ' &path '; 5. Archive mode and non-archive Mode conversion Reverse process of 4th step . 6. Configuring multiple Archive Processes Q: When to use multiple archive processes? A: If the archiving process consumes a lot of time, you can start multiple archive processes, which is a dynamic parameter that can be used with alter You can specify up to 10 archive processes in the system dynamic modification . sql>alter system SET log_archive_max_processes=10; oracle9i Dynamic performance views related to the archive process v$bgprocess,v$archive_processes 7. Configure archiving targets, multi-archive targets, remote archive targets, archive log formats archive targets Log_archive_ dest_n Local archive target: sql>log_archive_dest_1 = "Location=d:oraclearchivedlog"; Remote archive destination: SQL> log_archive_dest_2 = "SERVICE=STANDBY_DB1"; mandatory archive target, if error, retry: sql>alter SYSTEM SET log_archive_ after 600 seconds Dest_4 = "Location=e:oraclearchivedlog MANDATORY reopen=600"; Optional archive target, if error, discard archive: sql>alter SYSTEM SET LO G_archive_dest_3 = "Location=e:oraclearchivedlog OPTIONAL"; Archive target status: Close archive target and open archive target Close archive target 1 sql> ALTER SYSTEM SET log_archive_dest_state_1 = defer Open Archive target2 sql>alter SYSTEM SET log_archive_dest_state_2 = enable Archive log format log_archive_format 8. Get archived logs Info v$archived_log v$archive_dest v$log_history v$database V$ARCHIVE_PROCESSES AR Chive LOG LIST;
See if the Oracle database is in archive mode
