• Parameter Vs Statistics Examples
• Parameter Vs Statistic Quiz

11Initialization ParametersThis chapter describes how to view the current database initialization parameters, how to modify a server parameter file (SPFILE), and provides reference information for the initialization parameters that affect instances in a Data Guard configuration.All database initialization parameters are contained in either an initialization parameter file (PFILE) or a server parameter file (SPFILE). As an alternative to specifying parameters in an initialization parameter file or server parameter file, you can modify dynamic parameters at runtime using the ALTER SYSTEM SET or ALTER SESSION SET statements. Note:You must use a server parameter file if you use the Data Guard broker. See Also:for information about these parameters that is not specific to Data Guard and for the type, default values, and syntax for these initialization parameters.

Also refer to your Oracle operating system-specific documentation for more information about setting initialization parameters.ARCHIVELAGTARGET DescriptionLimits the amount of data that can be lost and effectively increases the availability of the standby database by forcing a log switch after the amount of time you specify (in seconds) elapses. The standby database will not miss redo logs generated from a time range longer than a value of the ARCHIVELAGTARGET parameter.

RoleApplies to the primary database role ExamplesThe following example sets the log switch interval to 30 minutes (a typical value):ARCHIVELAGTARGET = 1800COMPATIBLE DescriptionControls the compatibility of your database. Set to 9.0.0.0.0 or higher to use the Data Guard broker, logical standby databases, and the enhanced features of physical standby databases. Always set this parameter to the same value on the primary database and standby databases.

If the values differ, you might not be able to archive the redo logs from the primary database to the standby database. RoleApplies to the primary and standby database roles ExamplesThe following example sets the database compatible level to '9.2.0.0.0':COMPATIBLE = '9.2.0.0.0'CONTROLFILERECORDKEEPTIME DescriptionSpecifies the minimum number of days before a reusable record in the control file can be reused. Use this parameter to avoid overwriting a reusable record in the control file (that contains needed information such as an archive log) for a specified period of time.

The range of values for this parameter is 0 to 356 days. If this parameter is set to 0, then the reusable records are reused as needed. RoleApplies to the primary and standby database roles ExamplesThe following example sets the minimum number of days before a reusable record in the control file can be reused to 20 days:CONTROLFILERECORDKEEPTIME = 20CONTROLFILES DescriptionSpecifies the names of one or more control files, separated by commas. Always set this parameter on the standby database to a different value than the CONTROLFILES parameter for the primary database, if these databases are on the same system. The filenames you specify with the CONTROLFILES parameter for the standby database must exist at the standby location.

RoleApplies to the primary and standby database roles ExamplesThe following example specifies two control files for the database instance:CONTROLFILE = ('/disk1/oracle/oradata/payroll/control01.ctl','/disk1/oracle/oradata/payroll/control02.ctl')DBFILENAMECONVERT DescriptionConverts the filename of a datafile on the primary database to a filename on the standby database. Because the standby database control file is a copy of the primary database control file, you must use this parameter to convert the standby database filenames when they are different from the primary database filenames. If the standby database is on the same system as the primary database, you must use different path names. RoleApplies to the physical standby database role ExamplesThe following example shows the conversion of paths from /dbs/t1/ (primary database) to /dbs/t1/stdby (standby database) and dbs/t2/ (primary database) to dbs/t2/stdby (standby database):DBFILENAMECONVERT = ('/dbs/t1/','/dbs/t1/stdby','dbs/t2/ ','dbs/t2/stdby')DBFILES DescriptionSpecifies the maximum number of database files that can be open for this database. The primary and standby databases should have the same value for this parameter. RoleApplies to the primary and standby database roles ExamplesThe following example specifies that a maximum of 300 database files can be open for this database instance:DBFILES = 300DBNAME DescriptionSpecifies a database identifier of up to eight characters. For a physical standby database, set the DBNAME parameter to the same value as it is set in the primary database initialization file.

For a logical standby database, set the DBNAME parameter to a different value from that in the primary database initialization files. Use the DBNEWID (nid) utility to set the database name for a logical standby database, as described in. RoleApplies to the primary and standby database roles ExamplesThe following example shows that the database name is Sales:DBNAME = SalesThe following example shows how to use the DBNEWID utility to set a logical standby database name. You must mount the database before issuing this command.nid TARGET=SYS/CHANGEONINSTALL@LogicalSDB DBNAME=SalesLSDB SETNAME=YESFALCLIENT DescriptionAssigns the fetch archive log (FAL) client name used by the FAL server to refer to the FAL client. This is the Oracle Net service name that the FAL server should use to refer to the standby database. This Oracle Net service name must be configured properly on the FAL server (primary database) to point to the FAL client. Given the dependency of the FALCLIENT parameter on the FALSERVER parameter, the two parameters should be configured or changed at the same time.

Parameter Vs Statistics Examples

This parameter is set on the standby site. RoleApplies to the physical standby database role in managed recovery mode ExamplesThe following example assigns the FAL client to the Oracle Net service name StandbyDB:FALCLIENT = StandbyDBFALSERVER DescriptionAssigns the Oracle Net service name that the standby database should use to connect to the fetch archive log (FAL) server. This parameter is set on the standby system. TypeString DefaultsNone RoleApplies to the physical standby database role in managed recovery mode ExamplesThe following example shows that the FAL server is assigned to the Oracle Net service name PrimaryDB:FALSERVER = PrimaryDBLOCKNAMESPACE DescriptionSpecifies the name space that the distributed lock manager (DLM) uses to generate lock names. Set this parameter to a unique value in each initialization parameter file if the standby database has the same name as the primary database and is on the same system or cluster. Note:If you do not set the LOCKNAMESPACE parameter differently when the standby and primary databases are located on the same system, you will receive an ORA-1102 error.RoleApplies to the primary and standby database roles ExamplesThe following example shows that the LOCKNAMESPACE is set to payroll2 in the standby initialization parameter file:LOCKNAMESPACE = payroll2LOGARCHIVEDEST n DescriptionDefines an archive log destination and attributes for log transport services.

This parameter is discussed in and in. RoleApplies to the primary and standby database roles ExamplesThe following example shows a remote archive log destination to a standby database:LOGARCHIVEDEST2 = 'SERVICE=payroll2 OPTIONAL REOPEN=180'LOGARCHIVEDESTSTATE n DescriptionSpecifies the state of the destination specified by the LOGARCHIVEDEST n parameter. The possible values are as follows:. ENABLE specifies that a valid log archive destination can be used for a subsequent archiving operation (automatic or manual). This is the default. DEFER specifies that valid destination information and attributes are preserved, but the destination is excluded from archiving operations until you reenable archiving with the ENABLE option. ALTERNATE specifies that the destination is not enabled, but will become enabled if communication to another destination fails.RoleApplies to the primary and standby database roles ExamplesThe following example shows the LOGARCHIVEDESTSTATE2 state is set to ENABLE:LOGARCHIVEDESTSTATE2 = ENABLELOGARCHIVEFORMAT DescriptionSpecifies the format for archived redo log filenames.

STANDBYARCHIVEDEST and LOGARCHIVEFORMAT initialization parameters are concatenated to generate fully-qualified standby database archived redo log filenames. RoleApplies to the primary and standby database roles ExamplesThe following example specifies the format for the archive redo log filename using a database ID (%d), thread (%t), and sequence number (%s):LOGARCHIVEFORMAT = 'log%d%t%s.arc'LOGARCHIVEMAXPROCESSES DescriptionSpecifies the number of archiver background processes to be invoked by the database server. This value is evaluated at instance startup if the LOGARCHIVESTART parameter has the value TRUE; otherwise, this parameter is evaluated when the archiver process is invoked. RoleApplies to the primary and standby database roles ExamplesThe following example sets the number of log archiver processes to 2:LOGARCHIVEMAXPROCESSES = 2LOGARCHIVEMINSUCCEEDDEST DescriptionDefines the minimum number of destinations that must receive redo logs successfully before the log writer process on the primary database can reuse the online redo logs. RoleApplies to the primary and standby database roles ExamplesThe following example sets the minimum number of destinations that must succeed to 2:LOGARCHIVEMINSUCCEEDDEST = 2LOGARCHIVESTART DescriptionIndicates if archiving should be automatic or manual when the instance starts up. To enable automatic archiving of filled log groups, set LOGARCHIVESTART in the initialization parameter file to TRUE.

To disable the automatic archiving of filled online redo log groups, set LOGARCHIVESTART to FALSE. You cannot specify this parameter in a server parameter file. RoleApplies to the primary and standby database roles ExamplesThe following example sets LOGARCHIVESTART to TRUE:LOGARCHIVESTART = TRUELOGARCHIVETRACE DescriptionControls trace output generated by the ARC n and LGWR processes and foreground processes on the primary database, and the RFS and FAL server processes on the standby database. It allows you to see the progression of the archivedd redo logs to the standby site. The Oracle database server writes an audit trail of the redo logs received from the primary database into a trace file.

Parameter Vs Statistic Quiz

You specify the location of the trace file using the USERDUMPDEST parameter.