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 (`ARC`n) 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.