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Oracle® Data Guard Concepts and Administration
10g Release 2 (10.2)

Part Number B14239-01
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14 LOG_ARCHIVE_DEST_n Parameter Attributes

This chapter provides reference information for the attributes of the LOG_ARCHIVE_DEST_n initialization parameter. The following list shows the attributes:


AFFIRM and NOAFFIRM
ALTERNATE
ARCH and LGWR
DB_UNIQUE_NAME
DELAY
DEPENDENCY
LOCATION and SERVICE
MANDATORY and OPTIONAL
MAX_CONNECTIONS
MAX_FAILURE
NET_TIMEOUT
NOREGISTER
REOPEN
SYNC and ASYNC
TEMPLATE
VALID_FOR
VERIFY

Each LOG_ARCHIVE_DEST_n destination must contain either a LOCATION or SERVICE attribute to specify a local disk directory or a remotely accessed database, respectively. All other attributes are optional.


Note:

Several attributes of the LOG_ARCHIVE_DEST_n initialization parameter have been deprecated. These attributes are supported for backward compatibility only and are documented in the Oracle Database Reference.


See Also:

Chapter 5 for more information about defining LOG_ARCHIVE_DEST_n destinations and setting up redo transport services.


AFFIRM and NOAFFIRM

Controls whether redo transport services use synchronous or asynchronous I/O to write redo data to disk:

Category AFFIRM NOAFFIRM
Data type Keyword Keyword
Valid values Not applicable Not applicable
Default Value Not applicable Not applicable
Requires attributes ... Not applicable Not applicable
Conflicts with attributes ... NOAFFIRM AFFIRM
Corresponds to ... AFFIRM and ASYNC_BLOCKS columns of the V$ARCHIVE_DEST view AFFIRM and ASYNC_BLOCKS columns of the V$ARCHIVE_DEST view

Usage Notes


See also:

SYNC and ASYNC attributes

Examples

The following example shows the AFFIRM attribute for a remote destination.

LOG_ARCHIVE_DEST_3='SERVICE=stby1 LGWR SYNC AFFIRM'
LOG_ARCHIVE_DEST_STATE_3=ENABLE

ALTERNATE

Specifies an alternate archiving destination to be used when the original destination fails.

Category ALTERNATE=LOG_ARCHIVE_DEST_n
Data Type String
Valid Value A LOG_ARCHIVE_DEST_n destination
Default Value None. If an alternate destination is not specified, then redo transport services do not automatically change to another destination.
Requires attributes ... Not applicable
Conflicts with attributes ... None Foot 1 
Corresponds to ... ALTERNATE and STATUS columns of the V$ARCHIVE_DEST view

Footnote 1 If the REOPEN attribute is specified with a nonzero value, the ALTERNATE attribute is ignored. If the MAX_FAILURE attribute is also specified with a nonzero value, and the failure count exceeds the specified failure threshold, the ALTERNATE destination is enabled. Therefore, the ALTERNATE attribute does not conflict with a nonzero REOPEN attribute value.

Usage Notes

Examples

In the sample initialization parameter file in Example 14-1, LOG_ARCHIVE_DEST_1 automatically fails over to LOG_ARCHIVE_DEST_2 on the next archival operation if an error occurs or the device becomes full.

Example 14-1 Automatically Failing Over to an Alternate Destination

LOG_ARCHIVE_DEST_1='LOCATION=/disk1 MANDATORY ALTERNATE=LOG_ARCHIVE_DEST_2'
LOG_ARCHIVE_DEST_STATE_1=ENABLE
LOG_ARCHIVE_DEST_2='LOCATION=/disk2 MANDATORY'
LOG_ARCHIVE_DEST_STATE_2=ALTERNATE

Notice in the example that a destination can also be in the ALTERNATE state, as specified with the LOG_ARCHIVE_DEST_STATE_n initialization parameter. The ALTERNATE state defers redo transport services from transmitting redo data to this destination until such time as another destination failure automatically enables this destination. Section 5.2.2 provides more information about the LOG_ARCHIVE_DEST_STATE_n parameter.

Example 14-2 Defining an Alternate Oracle Net Service Name to the Same Standby Database

This example shows how to define an alternate Oracle Net service name to the same standby database.

LOG_ARCHIVE_DEST_1='LOCATION=/disk1 MANDATORY'
LOG_ARCHIVE_DEST_STATE_1=ENABLE
LOG_ARCHIVE_DEST_2='SERVICE=stby1_path1 OPTIONAL ALTERNATE=LOG_ARCHIVE_DEST_3'
LOG_ARCHIVE_DEST_STATE_2=ENABLE
LOG_ARCHIVE_DEST_3='SERVICE=stby1_path2 OPTIONAL'
LOG_ARCHIVE_DEST_STATE_3=ALTERNATE

ARCH and LGWR

Specifies whether redo transport services use archiver processes (ARCn) or the log writer process (LGWR) to collect transaction redo data and transmit it to standby destinations. If neither the ARCH or LGWR attributes are specified, the default is ARCH.

Category ARCH LGWR
Data Type Keyword Keyword
Valid values Not applicable Not applicable
Default value Not applicable Not applicable
Requires attributes ... None None
Conflicts with attributes ... LGWR, ASYNC, NET_TIMEOUT ARCH
Corresponds to ... ARCHIVER, PROCESS, and SCHEDULE columns of the V$ARCHIVE_DEST view ARCHIVER, PROCESS, and SCHEDULE columns of the V$ARCHIVE_DEST view

Usage Notes

Example

The following example shows the LGWR attribute with the LOG_ARCHIVE_DEST_n parameter. See Section 5.3 for more examples.

LOG_ARCHIVE_DEST_3='SERVICE=denver LGWR'
LOG_ARCHIVE_DEST_STATE_3=ENABLE

DB_UNIQUE_NAME

Specifies a unique name for the database at this destination.

Category DB_UNIQUE_NAME=name
Data Type String
Valid values The name must match the value that was defined for this database with the DB_UNIQUE_NAME parameter.
Default value None
Requires attributes ... None
Conflicts with attributes ... None
Corresponds to ... DB_UNIQUE_NAME column of the V$ARCHIVE_DEST view

Usage Notes

Example

In the following example, the DB_UNIQUE_NAME parameter specifies boston (DB_UNIQUE_NAME=boston), which is also specified with the DB_UNIQUE_NAME attribute on the LOG_ARCHIVE_DEST_1 parameter. The DB_UNIQUE_NAME attribute on the LOG_ARCHIVE_DEST_2 parameter specifies the chicago destination. Both boston and chicago are listed in the LOG_ARCHIVE_CONFIG=DG_CONFIG parameter.

DB_UNIQUE_NAME=boston
LOG_ARCHIVE_CONFIG='DG_CONFIG=(chicago,boston,denver)'
LOG_ARCHIVE_DEST_1='LOCATION=/arch1/ 
  VALID_FOR=(ALL_LOGFILES,ALL_ROLES) 
  DB_UNIQUE_NAME=boston'
LOG_ARCHIVE_DEST_2='SERVICE=Sales_DR 
  VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) 
  DB_UNIQUE_NAME=chicago'

DELAY

Specifies a time lag between when redo data is archived on a physical standby site and when the archived redo log file is applied to the physical standby database.


Note:

You can set this attribute only for physical standby databases. To delay the application of archived redo log files on a logical standby databases, use the DBMS_LOGSTDBY.APPLY_SET procedure as described in Oracle Database PL/SQL Packages and Types Reference.

Category DELAY[=minutes]
Data Type Numeric
Valid values >=0 minutes
Default Value 30 minutes
Requires attributes ... SERVICE
Conflicts with attributes ... LOCATION, NODELAY
Corresponds to ... DELAY_MINS and DESTINATION columns of the V$ARCHIVE_DEST view

Usage Notes

Examples

You can use the DELAY attribute to set up a configuration where multiple standby databases are maintained in varying degrees of synchronization with the primary database. However, this protection incurs some overhead during failover, because it takes Redo Apply more time to apply all the redo up to the corruption point.

For example, assume primary database A has standby databases B and C. Standby database B is set up as the disaster recovery database and therefore has no time lag. Standby database C is set up with a 2-hour delay, which is enough time to allow user errors to be discovered before they are propagated to the standby database.

The following example shows how to specify the DELAY attribute for this configuration:

LOG_ARCHIVE_DEST_1='LOCATION=/oracle/dbs/'
LOG_ARCHIVE_DEST_STATE_1=ENABLE
LOG_ARCHIVE_DEST_2='SERVICE=stbyB LGWR SYNC AFFIRM'
LOG_ARCHIVE_DEST_STATE_2=ENABLE
LOG_ARCHIVE_DEST_3='SERVICE=stbyC DELAY=120'
LOG_ARCHIVE_DEST_STATE_3=ENABLE

Note:

Alternatively, you can use Flashback Database to revert the database to a point-in-time or SCN in a different database incarnation as long as there is sufficient flashback log data. Using Flashback Database is described in Oracle Database Backup and Recovery Basics.


DEPENDENCY

Specify this attribute for a standby destination that will receive redo data through shared access to an archival location at another destination. A destination defined with this attribute has a dependency on another destination, which is specified by the DEPENDENCY attribute.

Category DEPENDENCY=LOG_ARCHIVE_DEST_n
Data Type String value
Valid values Not applicable
Default Value None
Requires attributes ... SERVICE
Conflicts with attributes ... LOCATION, NOREGISTER
Corresponds to ... DEPENDENCY column of the V$ARCHIVE_DEST view

Usage Notes


LOCATION and SERVICE

Each destination must specify either the LOCATION or the SERVICE attribute to identify either a local disk directory or a remote database destination where redo transport services can transmit redo data.

Category LOCATION=local_disk_directory or USE_DB_RECOVERY_FILE_DEST SERVICE=net_service_name
Data Type String value String value
Valid values Not applicable Not applicable
Default Value None None
Requires attributes. . . Not applicable Not applicable
Conflicts with attributes ... SERVICE, DELAY, DEPENDENCY, NOREGISTER, ASYNC, TEMPLATE, NET_TIMEOUT LOCATION
Corresponds to ... DESTINATION and TARGET columns of the V$ARCHIVE_DEST view DESTINATION and TARGET columns of the V$ARCHIVE_DEST view

Usage Notes

Examples


Example 1 Specifying the LOCATION Attribute

LOG_ARCHIVE_DEST_2='LOCATION=/disk1/oracle/oradata/payroll/arch/'
LOG_ARCHIVE_DEST_STATE_2=ENABLE

Example 2 Specifying the SERVICE Attribute

LOG_ARCHIVE_DEST_3='SERVICE=stby1'
LOG_ARCHIVE_DEST_STATE_3=ENABLE

MANDATORY and OPTIONAL

Specifies the policy for reusing online redo log files:

Category MANDATORY OPTIONAL
Data Type Keyword Keyword
Valid values Not applicable Not applicable
Default Value Not applicable Not applicable
Requires attributes ... Not applicable Not applicable
Conflicts with attributes ... OPTIONAL MANDATORY
Corresponds to ... BINDING column of the V$ARCHIVE_DEST view BINDING column of the V$ARCHIVE_DEST view

Usage Notes

Examples

The following example shows the MANDATORY attribute:

LOG_ARCHIVE_DEST_1='LOCATION=/arch/dest MANDATORY'
LOG_ARCHIVE_DEST_STATE_1=ENABLE
LOG_ARCHIVE_DEST_3='SERVICE=denver MANDATORY'
LOG_ARCHIVE_DEST_STATE_3=ENABLE

MAX_CONNECTIONS

Specifies the maximum number of network connections that will be used to perform remote archival to the destination. If the MAX_CONNECTIONS attribute is set to a value greater than 1, redo transport services use multiple network connections to perform remote archivals. Each of these connections use a separate archiver (ARCn) process.

Category Description
Data Type Integer
Valid values 1 to 5
Default value 1
Requires attributes ... None
Conflicts with attributes ... None
Corresponds to ...
  • MAX_CONNECTIONS column of the V$ARCHIVE_DEST view of the primary database
  • LOG_ARCHIVE_MAX_PROCESSES and PARALLEL_MAX_SERVERS initialization parameters


Usage Notes

Examples

The following example shows the MAX_CONNECTIONS attribute:

LOG_ARCHIVE_DEST_1='LOCATION=/arch/dest'
LOG_ARCHIVE_DEST_STATE_1=ENABLE
LOG_ARCHIVE_DEST_3='SERVICE=denver MAX_CONNECTIONS=3'
LOG_ARCHIVE_DEST_STATE_3=ENABLE

MAX_FAILURE

Controls the consecutive number of times redo transport services attempt to reestablish communication and transmit redo data to a failed destination before the primary database gives up on the destination.

Category MAX_FAILURE=count
Data Type Numeric
Valid value >=0
Default Value None
Requires attributes ... REOPEN
Conflicts with attributes ... None
Corresponds to ... MAX_FAILURE, FAILURE_COUNT, and REOPEN_SECS columns of the V$ARCHIVE_DEST view

Usage Notes

Examples

The following example allows redo transport services up to three consecutive archival attempts, tried every 5 seconds, to the arc_dest destination. If the archival operation fails after the third attempt, the destination is treated as if the REOPEN attribute was not specified.

LOG_ARCHIVE_DEST_1='LOCATION=/arc_dest REOPEN=5 MAX_FAILURE=3'
LOG_ARCHIVE_DEST_STATE_1=ENABLE

NET_TIMEOUT

Specifies the number of seconds the log writer process on the primary system waits for status from the network server (LNSn) process before terminating the network connection.

Category NET_TIMEOUT=seconds
Data Type Numeric
Valid values 1Foot 1  to 1200
Default Value 180 seconds
Requires attributes ... LGWR with SYNC
Conflicts with attributes ... ARCH, LOCATION, LGWR with ASYNCFoot 2 
Corresponds to ... NET_TIMEOUT column of the V$ARCHIVE_DEST view of the primary database

Footnote 1 Although a minimum value of 1 second is allowed, Oracle recommends 8 to 10 seconds as a minimum to avoid false errors and disconnection from the standby database.
Footnote 2 If you specify the LGWR and ASYNC attributes, redo transport services ignore them; no error is returned.

Usage Notes

Examples

The following example shows how to specify a 40-second network timeout value on the primary database with the NET_TIMEOUT attribute.

LOG_ARCHIVE_DEST_2='SERVICE=stby1 LGWR NET_TIMEOUT=40 SYNC'
LOG_ARCHIVE_DEST_STATE_2=ENABLE

NOREGISTER

Indicates that the location of the archived redo log file is to be recorded at the corresponding destination.

Category NOREGISTER
Data Type Keyword
Valid values Not applicable
Default Value Not applicable
Requires attributes ... SERVICE
Conflicts with attributes ... LOCATION
Corresponds to ... DESTINATION and TARGET columns of the V$ARCHIVE_DEST view

Usage Notes

Examples

The following example shows the NOREGISTER attribute:

LOG_ARCHIVE_DEST_5='NOREGISTER'

REOPEN

Specifies the minimum number of seconds before redo transport services should try to reopen a failed destination.

Category REOPEN [=seconds]
Data Type Numeric
Valid values >=0 seconds
Default Value 300 seconds
Requires attributes ... None
Conflicts with attributes ... Not applicable
Corresponds to ... REOPEN_SECS and MAX_FAILURE columns of the V$ARCHIVE_DEST view

Usage Notes]

Examples

The following example shows the REOPEN attribute.

LOG_ARCHIVE_DEST_3='SERVICE=stby1 MANDATORY REOPEN=60'
LOG_ARCHIVE_DEST_STATE_3=ENABLE

SYNC and ASYNC

Specifies that network I/O is to be done synchronously (SYNC) or asynchronously (ASYNC) when archival is performed using the log writer process (LGWR).


Note:

When the primary database is in maximum protection mode or maximum availability mode, destinations archiving to standby redo log files and using the log writer process are automatically placed in SYNC mode.

Category SYNC ASYNC
Data Type Keyword Numeric
Valid values Not applicable 0 to 102,400Foot 1 Not applicable
Default Value Not applicable 61,440 blocksNone
Requires attributes ... None LGWR
Conflicts with attributes ... ASYNC SYNC, LOCATION, ARCH
Corresponds to ... TRANSMIT_MODE column of the V$ARCHIVE_DEST view TRANSMIT_MODE and ASYNC_BLOCKS columns of the V$ARCHIVE_DEST view

Footnote 1 The actual allowable value may be lower, depending on your operating system. Data Guard dynamically adjusts the value down to an appropriate number of blocks, if necessary.

Usage Notes

Examples

The following example shows the SYNC attribute with the LOG_ARCHIVE_DEST_n parameter.

LOG_ARCHIVE_DEST_3='SERVICE=stby1 LGWR SYNC'
LOG_ARCHIVE_DEST_STATE_3=ENABLE

TEMPLATE

Defines a directory specification and format template for names of archived redo log files at the destination. The template is used to generate a filename that is different from the default filename format defined by the STANDBY_ARCHIVE_DEST and LOG_ARCHIVE_FORMAT initialization parameters at the standby destination.

Category TEMPLATE=filename_template_%t_%s_%r
Data Type String value
Valid values Not applicable
Default Value None
Requires attributes ... SERVICE
Conflicts with attributes ... LOCATION
Corresponds to ... REMOTE_TEMPLATE and REGISTER columns of the V$ARCHIVE_DEST view

Usage Notes

Examples

In the following example, prmy1 transmits redo data to the remote destination, stby1. The TEMPLATE attribute indicates that stby1 is located in the directory /usr/oracle/prmy1 with the p1_thread#_sequence#_resetlogs.dbf filename format.

LOG_ARCHIVE_DEST_1='SERVICE=boston MANDATORY REOPEN=5
    TEMPLATE=/usr/oracle/prmy1/p1_%t_%s_%r.dbf'
LOG_ARCHIVE_DEST_STATE_1=ENABLE

VALID_FOR

Specifies when redo transport services transmit redo data to a destination, based on the following factors:

Category VALID_FOR=(redo_log_type, database_role)
Data Type String value
Valid values Not applicable
Default Value VALID_FOR=(ALL_LOGFILES, ALL_ROLES) Foot 1 
Requires attributes ... None
Conflicts with attributes ... None
Corresponds to ... VALID_NOW, VALID_TYPE, and VALID_ROLE columns in the V$ARCHIVE_DEST view

Footnote 1 Do not use the default value, VALID_FOR=(ALL LOGFILES, ALL_ROLES), for logical standby databases. See Section 5.4.1 and the scenario in Section 12.1.2 for more information.

Usage Notes

Example

The following example shows the default VALID_FOR keyword pair:

LOG_ARCHIVE_DEST_1='LOCATION=/disk1/oracle/oradata VALID_FOR=(ALL LOGFILES, ALL_ROLES)'

When this database is running in either the primary or standby role, destination 1 archives all log files to the /disk1/oracle/oradata local directory location.

See the scenarios in Section 12.1 for detailed examples of various Data Guard configurations using the VALID_FOR attribute.


VERIFY

Indicates whether or not an archiver (ARCn) process should scan and verify the correctness of the contents of a completed archived redo log file, either local or remote, after successfully completing the archival operation.

Category VERIFY
Data Type Keyword
Valid values Not applicable
Default Value Not applicable
Requires attributes ... None
Conflicts with attributes ... LGWR
Corresponds to ... VERIFY and ARCHIVER columns in the V$ARCHIVE_DEST view

Usage Notes

Example

The following example shows the VERIFY attribute:

LOG_ARCHIVE_DEST_1='LOCATION=/disk1/oracle/oradata VERIFY'
LOG_ARCHIVE_DEST_2='LOCATION=/arch1/SRLs/ VALID_FOR=(STANDBY_LOGFILE, STANDBY_ROLE) VERIFY'
LOG_ARCHIVE_DEST_3='SERVICE=denver VALID_FOR=(ONLINE_LOGFILE,PRIMARY_ROLE) VERIFY'