Understanding Archive
Destination Status
Each archive destination has the following variable characteristics that
determine its status:
·
Valid/Invalid: indicates whether the disk location or service name information is
specified and valid
·
Enabled/Disabled: indicates the availability state of the location and whether the database
can use the destination
·
Active/Inactive: indicates whether there was a problem accessing the destination
Several combinations of these characteristics are
possible. To obtain the current status and other information about each
destination for an instance, query the V$ARCHIVE_DEST
view.The
LOG_ARCHIVE_DEST_STATE_n
(where n is an integer from 1 to 31) initialization
parameter lets you control the availability state of the specified destination
(n).
·
ENABLE
indicates that the database can use the destination.
·
DEFER
indicates that the location is temporarily disabled.
·
ALTERNATE indicates that the destination is
an alternate. The availability state of an alternate destination is DEFER. If its parent destination fails, the availability state
of the alternate becomes ENABLE. ALTERNATE cannot be specified for destinations LOG_ARCHIVE_DEST_11 to LOG_ARCHIVE_DEST_31.
Specifying Alternate Destinations
If you want
to specify that a location be an archive destination only in the event of a
failure of another destination, you can make it an alternate destination. Both
local and remote destinations can be alternates. The following example makes LOG_ARCHIVE_DEST_4 an
alternate for LOG_ARCHIVE_DEST_3:
ALTER SYSTEM SET LOG_ARCHIVE_DEST_4 =
'LOCATION=/disk4/arch';
ALTER SYSTEM SET LOG_ARCHIVE_DEST_3 =
'LOCATION=/disk3/arch
ALTERNATE=LOG_ARCHIVE_DEST_4';
ALTER SYSTEM SET
LOG_ARCHIVE_DEST_STATE_4=ALTERNATE;
SQL> SELECT dest_name, status, destination
FROM v$archive_dest;
DEST_NAME
STATUS DESTINATION
----------------------- --------- ----------------------------------------------
LOG_ARCHIVE_DEST_1
VALID /disk1/arch
LOG_ARCHIVE_DEST_2
VALID +RECOVERY
LOG_ARCHIVE_DEST_3
VALID /disk3/arch
LOG_ARCHIVE_DEST_4
ALTERNATE /disk4/arch
