11
Initialization Parameters

This chapter describes the initialization parameters that affect databases in a Data Guard environment.

Table 11-1 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 a Data Guard environment. Oracle Database Reference provides complete initialization parameter information, including how to set update initialization parameters by issuing the ALTER SYSTEM SET or ALTER SESSION statements (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 11-1  Initialization Parameters for Instances in a Data Guard Configuration

Parameter	Primary Role?	Standby Role?	Notes and Recommendations
ARCHIVE_LAG_TARGET = seconds	Yes	No	Optional. Forces a log switch after the specified number of seconds elapses.
COMPATIBLE = release_number	Yes	Logical and physical	Data Guard requires a minimum value of 9.2.0.1.0. Set to a minimum of 10.0.0.0 to use Oracle Database 10g new features. Specify the same value on the primary and standby databases. If the values differ, log transport services may be unable to transmit redo data from the primary database to the standby databases. See Section 3.2.3 and Section 4.2.3.2 for examples.
CONTROL_FILE_RECORD_KEEP_TIME = number_of_days	Yes	Logical and physical	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). See Section 5.7.4.
CONTROL_FILES = 'control_file_name' , control_file_name', '...')	Yes	Logical and physical	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 and Section 4.2.3.2 for examples.
DB_FILENAME_CONVERT = (location_of_primary_database_datafile' , 'location_of_standby_database_datafile_name' , '...'	No	Logical and physical	Required if the standby database is on the same system as the primary database or if the directory where the datafiles are located on the standby system is different from the primary system. 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 3-2.
DB_FILES = number_of_database_files_that_can_be_open_for_this_database	Yes	Logical and physical	Optional. Specify the same number of database files on the primary and standby databases.
DB_NAME = 8-character_database_name	Yes	Logical and physical	Required. For physical standby databases, specify the same DB_NAME that was specified for the primary database. For logical standby databases, use the DBNEWID utility to reset DB_NAME to specify a different name from the primary database, as described in Section 4.2.4.
DB_UNIQUE_NAME = unique_service_provider_name_for_this_database	Yes	Logical and physical	Required for remote destinations. Specify 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	Yes	Physical only	Required if the FAL_SERVER parameter is specified. Specifies the Oracle Net service name used by the FAL server (typically the primary database) to refer to the FAL client (standby database). See Section 5.8.3.
FAL_SERVER = Oracle_Net_service_name	No	Physical only	Required if the FAL_CLIENT parameter is specified. Specifies one or more Oracle Net service names for the databases from which this standby database can fetch (request) missing archived redo log files. See Section 5.8.3.
INSTANCE_NAME	Yes	Logical and physical	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 and Section 4.2.3.2 for examples.
LOG_ARCHIVE_CONFIG='DG_CONFIG=(db_unique_name, db_unique_name, ...)'	Yes	Logical and physical	Required. Specify the DG_CONFIG attribute to list the DB_UNIQUE_NAME for the primary database and each standby database in the Data Guard configuration. By default, this parameter enables the primary database to send redo data to remote destinations and enables standby databases to receive redo data. The DG_CONFIG attribute must be set to enable the dynamic addition of a standby database to a Data Guard configuration that has a Real Application Clusters primary database running in either maximum protection or maximum availability mode. See Section 5.4.2.
LOG_ARCHIVE_DEST_n = {LOCATION=path_name| SERVICE=service_name, attribute, attribute, ... }	Yes	Logical and physical	Required. Define up to ten (where n = 1, 2, 3, ... 10) 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. See Section 5.2.2 and Chapter 12 for more information.
LOG_ARCHIVE_DEST_STATE_n = {ENABLE|DISABLE|ALTERNATE}	Yes	Logical and physical	Required. Specify a LOG_ARCHIVE_DEST_STATE_n parameter to enable or disable log 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_nparameter. See also Section 5.2.2 and Chapter 12.
LOG_ARCHIVE_FORMAT=log%d_%t_%s_%r.arc	Yes	Logical and physical	Required if you specify the STANDBY_ARCHIVE_DEST parameter. These parameters are concatenated together to generate fully qualified archived redo log filenames on the standby database. See also Section 5.7.1.
LOG_ARCHIVE_LOCAL_FIRST =[TRUE|FALSE]	Yes	No	Optional. Specify to control when archiver processes (ARCn) transmit; either after (TRUE) the online redo log file was successfully archived to at least one local destination, or at the same time (FALSE) the online redo log file is being archived to local destinations. See also Section 5.3.1.
LOG_ARCHIVE_MAX_PROCESSES =integer	Yes	Logical and physical	Optional. Specify the number (from 1 to 10) of archiver processes you want Oracle software to invoke initially.
LOG_ARCHIVE_MIN_SUCCEED_DEST=integer	Yes	No	Optional. Define the minimum number (from 1 to 10) of destinations that must receive redo data successfully before the log writer process on the primary database can reuse the online redo log file.
LOG_ARCHIVE_TRACE=integer	Yes	Logical and physical	Optional. Set this parameter to trace the transmission of redo data to the standby site. The valid integer values (0, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, or 4096) are described in Appendix E.
LOG_FILE_NAME_CONVERT ='location_of_primary_database_redo_logs', 'location_of_standby_database_redo_logs'	No	Logical and physical	Required when the standby database is on the same system as the primary database or when the directory structure where the log files are located on the standby site is different from the primary site. 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 and Section 4.2.3.2 for examples.
PARALLEL_MAX_SERVERS=integer	Yes	Logical only	Required. Specify the maximum number of parallel servers working on the logical standby database. This parameter must not be set to a value less than 5 on a logical standby database. For best results, set PARALLEL_MAX_SERVERS to a minimum of 9. See also Section 9.4.
REMOTE_LOGIN_PASSWORDFILE= {EXCLUSIVE|SHARED]	Yes	Logical and physical	Required. Specify on the primary and all standby databases to ensure Data Guard transmits redo data only after the appropriate authentication checks using SYS credentials are successful. Include either the EXCLUSIVE or SHARED values to control how many databases can use the password file. See also Section 5.3.3.
SERVICE_NAMES	Yes	Yes	Specify a service name for this standby database that is unique from the primary database service name. If you do not explicitly specify unique service names and the primary and standby databases are located on the same system, the same default global name (consisting of the database name, DB_NAME, and domain name, DB_DOMAIN, parameters) will be in effect for both databases.
SHARED_POOL_SIZE = bytes	Yes	Logical and physical	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.
SORT_AREA_SIZE = bytes	Yes	Logical and physical	Optional. Increase the SORT_AREA_SIZE size (default size is 65536 bytes) to improve the efficiency of large sorts. See also Section 8.2.
STANDBY_ARCHIVE_DEST= filespec	No	Logical and physical	Optional. Specify the location of archived redo log files on the standby database. The STANDBY_ARCHIVE_DEST initialization parameter overrides the directory location specified with the LOG_ARCHIVE_DEST_n parameter. STANDBY_ARCHIVE_DEST and LOG_ARCHIVE_FORMAT are concatenated to generate fully qualified log filenames. See Section 5.7.1.
STANDBY_FILE_MANAGEMENT = {AUTO|MANUAL}	Yes	Logical and physical	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 datafiles on the primary database to filenames on the standby database. See Example 3-2 for more information and examples.
USER_DUMP_DEST = directory_path_name_of_trace_file	Yes	Logical and physical	Required if you specify the LOG_ARCHIVE_TRACE parameter. The USER_DUMP_DEST specifies the path name for a directory where the server will write debugging trace files. See Appendix E.