16 Initialization Parameters

This chapter describes the database initialization parameters that affect databases in an Oracle Data Guard environment.

Table 16-1 lists the initialization parameters and indicates if the parameter applies to the primary database role, the standby database role, or both. The table also includes notes and recommendations specific to setting the parameters in an Oracle Data Guard environment. Oracle Database Reference provides complete initialization parameter information, including how to update initialization parameters by issuing the ALTER SYSTEM SET statement (for example, ALTER SYSTEM SET LOG_ARCHIVE_TRACE) or by editing the initialization parameter files. See the Oracle operating system-specific documentation for more information about setting initialization parameters.

Table 16-1 Initialization Parameters for Instances in an Oracle Data Guard Configuration

Parameter Applicable To Notes and Recommendations

COMPATIBLE = release_number

Primary

Logical Standby

Physical Standby

Snapshot Standby

Specify the same value on the primary and standby databases if you expect to do a switchover. If the values differ, redo transport services may be unable to transmit redo data from the primary database to the standby databases. See Section 3.2.3 for an example.

A logical standby database can have a higher COMPATIBLE setting than the primary database if a switchover is not expected.

For rolling upgrades using SQL Apply, set this parameter according to the guidelines described in Section 13.4, "Performing a Rolling Upgrade By Creating a New Logical Standby Database".

CONTROL_FILE_RECORD_KEEP_TIME = number_of_days

Primary

Logical Standby

Physical Standby

Snapshot Standby

Optional. Use this parameter to avoid overwriting a reusable record in the control file (that contains needed information such as an archived redo log file) for the specified number of days (from 0 to 365).

CONTROL_FILES = 'control_file_name', 'control_file_name', '...'

Primary

Logical Standby

Physical Standby

Snapshot Standby

Required. Specify the path name and filename for one or more control files. The control files must already exist on the database. Oracle recommends using 2 control files. If another copy of the current control file is available, then an instance can be easily restarted after copying the good control file to the location of the bad control file. See Section 3.2.3 for an example.

DB_FILE_NAME_CONVERT = 'location_of_primary_database_datafile','location_of_standby_database_datafile'

Physical Standby

Snapshot Standby

This parameter must specify paired strings. The first string is a sequence of characters to be looked for in a primary database filename. If that sequence of characters is matched, it is replaced by the second string to construct the standby database filename. You can specify multiple pairs of filenames. See also Example 3-1.

DB_UNIQUE_NAME = Unique name for the database

Primary

Logical Standby

Physical Standby

Snapshot Standby

Recommended, but required if you specify the LOG_ARCHIVE_CONFIG parameter. Specifies a unique name for this database. This name does not change even if the primary and standby databases reverse roles. The DB_UNIQUE_NAME parameter defaults to the value of the DB_NAME parameter.

FAL_CLIENT = Oracle_Net_service_name

Physical Standby

Snapshot Standby

This parameter is no longer required. If it is not set, the fetch archive log (FAL) server will obtain the client's network address from the LOG_ARCHIVE_DEST_n parameter that corresponds to the client's DB_UNIQUE_NAME.

FAL_SERVER = Oracle_Net_service_name

Physical Standby

Snapshot Standby

Specifies one or more Oracle Net service names for the databases from which this standby database can fetch (request) missing archived redo log files.

INSTANCE_NAME

Primary

Logical Standby

Physical Standby

Snapshot Standby

Optional. If this parameter is defined and the primary and standby databases reside on the same host, specify a different name for the standby database than you specify for the primary database. See Section 3.2.3 for an example.

LOG_ARCHIVE_CONFIG ='DG_CONFIG=(db_unique_name, db_unique_name, ... )'

Primary

Logical Standby

Physical Standby

Snapshot Standby

Highly recommended. The DG_CONFIG attribute of this parameter must be explicitly set on each database in an Oracle Data Guard configuration to enable full Oracle Data Guard functionality. Set DG_CONFIG to a text string that contains the DB_UNIQUE_NAME of each database in the configuration, with each name in this list separated by a comma.

LOG_ARCHIVE_DEST_n = {LOCATION=path_name | SERVICE=service_name, attribute, attribute, ...}

Primary

Logical Standby

Physical Standby

Snapshot Standby

Required. Define up to thirty (where n = 1, 2, 3, ... 31) destinations, each of which must specify either the LOCATION or SERVICE attribute. Specify a corresponding LOG_ARCHIVE_DEST_STATE_n parameter for every LOG_ARCHIVE_DEST_n parameter.

LOG_ARCHIVE_DEST_STATE_n = {ENABLE|DEFER|ALTERNATE}

Primary

Logical Standby

Physical Standby

Snapshot Standby

Required. Specify a LOG_ARCHIVE_DEST_STATE_n parameter to enable or disable redo transport services to transmit redo data to the specified (or to an alternate) destination. Define a LOG_ARCHIVE_DEST_STATE_n parameter for every LOG_ARCHIVE_DEST_n parameter. See also Chapter 17.

LOG_ARCHIVE_FORMAT=log%d_%t_%s_%r.arc

Primary

Logical Standby

Physical Standby

Snapshot Standby

The LOG_ARCHIVE_FORMAT and LOG_ARCHIVE_DEST_n parameters are concatenated together to generate fully qualified archived redo log filenames on a database.

LOG_ARCHIVE_MAX_PROCESSES =integer

Primary

Logical Standby

Physical Standby

Snapshot Standby

Optional. Specify the number (from 1 to 30) of archiver (ARCn) processes you want Oracle software to invoke initially. The default value is 4.

LOG_ARCHIVE_MIN_SUCCEED_DEST

Primary

Logical Standby

Physical Standby

Snapshot Standby

Optional. This parameter specifies the number of local or remote MANDATORY destinations, or local OPTIONAL destinations, that a logfile group must be archived to before it can be re-used.

LOG_ARCHIVE_TRACE=integer

Primary

Logical Standby

Physical Standby

Snapshot Standby

Optional. Set this parameter to trace the transmission of redo data to the standby site. The valid integer values are described in Appendix F.

LOG_FILE_NAME_CONVERT = 'location_of_primary_database_redo_logs','location_of_standby_database_redo_logs'

Logical Standby

Physical Standby

Snapshot Standby

This parameter converts the path names of the primary database online redo log file to path names on the standby database. See Section 3.2.3 for an example.

REMOTE_LOGIN_PASSWORDFILE = {EXCLUSIVE|SHARED}

Primary

Logical Standby

Physical Standby

Snapshot Standby

Optional if operating system authentication is used for administrative users and SSL is used for redo transport authentication. Otherwise, this parameter must be set to EXCLUSIVE or SHARED on every database in an Oracle Data Guard configuration.

SHARED_POOL_SIZE = bytes

Primary

Logical Standby

Physical Standby

Snapshot Standby

Optional. Use to specify the system global area (SGA) to stage the information read from the online redo log files. The more SGA that is available, the more information that can be staged.

STANDBY_ARCHIVE_DEST = filespec

Logical Standby

Physical Standby

Snapshot Standby

This parameter has been deprecated and is maintained for backward compatibility only.

STANDBY_FILE_MANAGEMENT = {AUTO | MANUAL}

Primary

Physical Standby

Snapshot Standby

Set the STANDBY_FILE_MANAGEMENT parameter to AUTO so that when data files are added to or dropped from the primary database, corresponding changes are made in the standby database without manual intervention. If the directory structures on the primary and standby databases are different, you must also set the DB_FILE_NAME_CONVERT initialization parameter to convert the filenames of one or more sets of data files on the primary database to filenames on the (physical) standby database. See Example 3-1 for more information and examples.