NOARCHIVELOG Mode
Implications of NOARCHIVELOG Mode
- If a tablespace becomes unavaliable because of a failure,you cannot continue to operate the database until the tablespace has been dropped or the entire database has been restored from backups.
Auto and Manual Archiving
oracle server有归档模式与非归档模式之分，如果是归档模式，又分自动归档模式和手动归档模式；
archive log的启动与关闭
- 查看archive 状态信息命令
- archive log list
- 启动archive log
- alter system archive log start to '/u01/admin/denver/archdest';
- 停止archive log
- alter system archive log stop;
- 手动归档
- alter system archive log current;
- 异常排查
SQL> alter system set log_archive_start=true scope=both; alter system set log_archive_start=true scope=both * ERROR at line 1: ORA-02095: specified initialization parameter cannot be modified
ALTER SYSTEM ARCHIVE LOG
| Option | Description |
| THREAD | Specifies thread containing the redo log file group to be achived (for Oracle Parallel Server) |
| SEQUENCE | Archives the online redo log file group identified by the log sequence number |
| CHANGE | Archives based upon the SCN |
| GROUP | Archives the online redo log file group |
| CURRENT | Archives the current redo log file group of the specified thread |
| LOGFILE | Archives the redo log file group with members identied by filename |
| NEXT | Archives the oldest online redo log file group that has not been archived |
| ALL | Archives all online redo log file groups from the specified thread that are full but have not been archived. |
| START | Enables automatic archiving of redo log file groups |
| TO | Specifies the location to which the redo log file group is archived |
| STOP | Disables automatic archiving of redo log file groups |
问题跟踪：执行了alter system archive log stop;命令之后，Automatic archival 还是Enabled，这是为什么？
SQL> alter system archive log stop; System altered. SQL> archive log list; Database log mode Archive Mode Automatic archival Enabled Archive destination USE_DB_RECOVERY_FILE_DEST Oldest online log sequence 10 Next log sequence to archive 12 Current log sequence 12