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