Oracle：FRA,快速恢复区
Oracle的FRA是通过两个初始化参数启用的，它们分别为：
db_recovery_file_dest_size
db_recovery_file_dest
FRA为磁盘上的一块区域，主要用于存储以下文件类型：
归档文件
RMAN备份文件
闪回日志
控制文件
联机重做日志
关于初始化参数的细节：
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SQL> show parameter db_recovery_file_dest NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ db_recovery_file_dest string /u01/app/oracle/fast_recovery_ area db_recovery_file_dest_size big integer 4560M SQL> |
需要注意的是，归档日志到底会被存放在哪里，需要通过“archive log list”确认：
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SQL> archive log list; Database log mode Archive Mode Automatic archival Enabled Archive destination USE_DB_RECOVERY_FILE_DEST Oldest online log sequence 23 Next log sequence to archive 25 Current log sequence 25 SQL> |
如果如上显示“USE_DB_RECOVERY_FILE_DEST”，则表示重做日志正在被写入FRA。
它的具体路径为参数“db_recovery_file_dest”指定的值，即：/u01/app/oracle/fast_recovery_area。
如果设置了“log_archive_dest_n”，则归档日志将不会被写入FRA，而是被写入设定的：log_archive_dest_n，指定的路径。
具体情况如下所示：
首先，创建新的归档路径：
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[root@ora12c ~]# su - oracle [oracle@ora12c - allah:~]$ cd $ORACLE_BASE [oracle@ora12c - allah:/u01/app/oracle]$ ls -altr total 36 drwxr-xr-x 3 oracle oinstall 4096 Oct 15 20:58 product drwxr-xr-x 6 oracle oinstall 4096 Oct 16 00:23 .. drwxrwxr-x 19 oracle oinstall 4096 Oct 16 01:51 diag drwxr-x--- 4 oracle oinstall 4096 Oct 27 19:15 cfgtoollogs drwxr-x--- 5 oracle oinstall 4096 Oct 27 23:41 admin drwxr-xr-x 9 oracle oinstall 4096 Oct 27 23:41 . drwxr-x--- 4 oracle oinstall 4096 Oct 27 23:41 fast_recovery_area drwxr-x--- 5 oracle oinstall 4096 Oct 27 23:44 audit drwxr-xr-x 2 oracle oinstall 4096 Oct 27 23:49 checkpoints [oracle@ora12c - allah:/u01/app/oracle]$ [oracle@ora12c - allah:/u01/app/oracle]$ mkdir archive_data [oracle@ora12c - allah:/u01/app/oracle]$ cd archive_data/ [oracle@ora12c - allah:/u01/app/oracle/archive_data]$ ls [oracle@ora12c - allah:/u01/app/oracle/archive_data]$ |
然后，通过SQL*Plus，进入数据库修改：
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SQL> archive log list Database log mode Archive Mode Automatic archival Enabled Archive destination USE_DB_RECOVERY_FILE_DEST Oldest online log sequence 23 Next log sequence to archive 25 Current log sequence 25 SQL> SQL> show parameter log_archive_dest_1 NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ log_archive_dest_1 string log_archive_dest_10 string log_archive_dest_11 string log_archive_dest_12 string log_archive_dest_13 string log_archive_dest_14 string log_archive_dest_15 string log_archive_dest_16 string log_archive_dest_17 string log_archive_dest_18 string log_archive_dest_19 string SQL> show parameter log_archive_dest_state_1 NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ log_archive_dest_state_1 string enable log_archive_dest_state_10 string enable log_archive_dest_state_11 string enable log_archive_dest_state_12 string enable log_archive_dest_state_13 string enable log_archive_dest_state_14 string enable log_archive_dest_state_15 string enable log_archive_dest_state_16 string enable log_archive_dest_state_17 string enable log_archive_dest_state_18 string enable log_archive_dest_state_19 string enable SQL> SQL> SQL> alter system set log_archive_dest_1='location=/u01/app/oracle/archive_data'; System altered. SQL> show parameter log_archive_dest_1; NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ log_archive_dest_1 string location=/u01/app/oracle/archi ve_data log_archive_dest_10 string log_archive_dest_11 string log_archive_dest_12 string log_archive_dest_13 string log_archive_dest_14 string log_archive_dest_15 string log_archive_dest_16 string log_archive_dest_17 string log_archive_dest_18 string log_archive_dest_19 string SQL> SQL> archive log list; Database log mode Archive Mode Automatic archival Enabled Archive destination /u01/app/oracle/archive_data Oldest online log sequence 23 Next log sequence to archive 25 Current log sequence 25 SQL> |
在发出日志切换，手动触发归档前，目标路径的状态：
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[oracle@ora12c - allah:/u01/app/oracle/archive_data]$ pwd /u01/app/oracle/archive_data [oracle@ora12c - allah:/u01/app/oracle/archive_data]$ ls -altr total 8 drwxr-xr-x 10 oracle oinstall 4096 Nov 13 20:18 .. drwxr-xr-x 2 oracle oinstall 4096 Nov 13 20:18 . [oracle@ora12c - allah:/u01/app/oracle/archive_data]$ |
发起日志切换，触发归档进程：
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SQL> select * from v$log; GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM NEXT_CHANGE# NEXT_TIME CON_ID ---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- --------- ------------ --------- ---------- 1 1 25 52428800 512 1 NO CURRENT 2410291 13-NOV-14 2.8147E+14 0 2 1 23 52428800 512 1 YES INACTIVE 2298628 12-NOV-14 2400793 13-NOV-14 0 3 1 24 52428800 512 1 YES INACTIVE 2400793 13-NOV-14 2410291 13-NOV-14 0 SQL> SQL> alter system switch logfile; System altered. SQL> SQL> select * from v$log; GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM NEXT_CHANGE# NEXT_TIME CON_ID ---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- --------- ------------ --------- ---------- 1 1 25 52428800 512 1 YES ACTIVE 2410291 13-NOV-14 2415318 13-NOV-14 0 2 1 26 52428800 512 1 NO CURRENT 2415318 13-NOV-14 2.8147E+14 0 3 1 24 52428800 512 1 YES INACTIVE 2400793 13-NOV-14 2410291 13-NOV-14 0 SQL> |
再次查看归档路径的状态：
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[oracle@ora12c - allah:/u01/app/oracle/archive_data]$ ls -altr total 12356 drwxr-xr-x 10 oracle oinstall 4096 Nov 13 20:18 .. -rw-r----- 1 oracle oinstall 12624384 Nov 13 20:26 1_25_862098262.dbf drwxr-xr-x 2 oracle oinstall 4096 Nov 13 20:26 . [oracle@ora12c - allah:/u01/app/oracle/archive_data]$ du -sh * 13M 1_25_862098262.dbf [oracle@ora12c - allah:/u01/app/oracle/archive_data]$ [oracle@ora12c - allah:/u01/app/oracle/archive_data]$ |
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Ending。
