log_archive_dest 和log_archive_dest_1 设置归档的区别

查看是否开启归档
SQL> archive log list;
Database log mode        No Archive Mode
Automatic archival        Disabled
Archive destination        /u01/app/oracle/product/12.2.0.1/db_1/dbs/arch
Oldest online log sequence     164
Current log sequence        165


开启归档
[root@rac1 bin]#su - grid
[grid@rac1 ~]$ srvctl stop database -d rac
[grid@rac1 ~]$ srvctl start database -d rac  -o mount
[grid@rac1 ~]$ exit
[root@rac1 bin]# su - oracle
[oracle@rac1 ~]$ sqlplus /nolog
SQL> alter database archivelog ;  
Database altered.

查看空间

SQL> select name, ROUND(FREE_MB/(1024), 2) from v$asm_diskgroup;

NAME        ROUND(FREE_MB/(1024),2)
------------------------------ -----------------------
CRS  29.15
DATA  36.07

MGMT  13.31

主要区别

1、设置方法不同

对比log_archive_dest 和log_archive_dest_1 设置归档的区别
alter system set log_archive_dest='+DATA'
alter system set log_archive_dest_1='location=+DATA'

2、这两个参数不能共存

3、

LOG_ARCHIVE_DEST_n参数可以设置最多10(n=[1..10])个不同的归档路径，通过设置关键词location或service，该参数指向的路径可以是本地或远程的。
log_archive_dest 使用log_archive_dest参数最多可设置2个归档路径，通过log_archive_dest设置一个主归档路径，通过LOG_ARCHIVE_DUPLEX_DEST 参数设置一个从归档路径





测试设置归档路径

方法一：log_archive_dest
alter system set log_archive_dest='+DATA'
SQL> show parameter dest 
log_archive_dest      string+DATA

SQL> alter system switch logfile;
System altered

[root@rac1 bin]#su - grid
[grid@rac1 ~]$asmcmd
ASMCMD> ls
thread_1_seq_165.279.958561519
thread_2_seq_173.280.958561585
ASMCMD> pwd
+DATA/rac/ARCHIVELOG/2017_10_28

方法二：log_archive_dest_1


alter system set log_archive_dest_1='location=+DATA'


SQL> alter system set log_archive_dest_1='location=+DATA'
  2  ;
alter system set log_archive_dest_1='location=+DATA'
*
ERROR at line 1:
ORA-02097: parameter cannot be modified because specified value is invalid
ORA-16019: cannot use LOG_ARCHIVE_DEST_1 with LOG_ARCHIVE_DEST or
LOG_ARCHIVE_DUPLEX_DEST


主要是由于log_archive_dest与log_archive_dest_n这两个参数是不能够同时设置值、共存的。


SQL>alter system set log_archive_dest=''

SQL>alter system set log_archive_dest_1='location=+DATA'

SQL> alter system switch logfile;
System altered

[root@rac1 bin]#su - grid
[grid@rac1 ~]$asmcmd