This chapter describes the initialization parameters that affect databases in a Data Guard environment.
Table 13-1 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 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 13-1 Initialization Parameters for Instances in a Data Guard Configuration
Parameter | Primary Role? | Standby Role? | Notes and Recommendations |
---|---|---|---|
|
Yes |
Physical only |
Optional. Forces a log switch after the specified number of seconds elapses. |
|
Yes |
Logical and physical |
Data Guard requires a minimum value of 9.2.0.1.0. Set to a minimum of 10.2.0.0 to use Oracle Database 10g new features. 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. For rolling upgrades using SQL Apply, set this parameter according to the guidelines described in Section 11.4, "Prepare to Upgrade". |
|
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. |
|
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 for an example. |
|
No |
Physical only |
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 3-3. |
|
Yes |
Logical and physical |
Recommended, but required if you specify the |
|
Yes |
Physical only |
Required if the |
|
No |
Physical only |
Required if the |
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 for an example. |
|
|
Yes |
Logical and physical |
Recommended. Specify the |
|
Yes |
Logical and physical |
Required. Define up to ten (where n = 1, 2, 3, ... 10) destinations, each of which must specify either the |
|
Yes |
Logical and physical |
Required. Specify a |
|
Yes |
Logical and physical |
Required if you specify the |
|
Yes |
No |
Optional. Specify to control when archiver processes (ARCn) transmit; either after ( See also Section 5.3.1. |
|
Yes |
Logical and physical |
Optional. Specify the number (from 1 to 30) of archiver ( |
|
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. |
|
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 G. |
|
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 for an example. |
|
Yes |
Logical only |
R |
|
Yes |
Logical and physical |
Required. Specify on the primary and all standby databases. |
|
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. |
|
Yes |
Logical and physical |
Optional. Increase the |
|
No |
Logical and physical |
Optional. Specify the location of archived redo log files received on the standby database from the primary database. The |
|
Yes |
Physical only |
Set the |
|
Yes |
Logical and physical |
Required if you specify the |