some of the parameters of oracle

Aug 11 posted in Oracle (RSS), 90 views.

A, AFFIRM and NOAFFIRM
Role: control log transport services are asynchronous or synchronous write log data to disk
AFFIRM: write in the log before the process, so the archive log and database log must at the same time prepare finished
NOFFIRM: in the main library to write log of all disk IO process, ranging from complete

The default is NOFFIRM
AFFIRM use, you can ensure that the following three points:
1 to ensure that data is not lost after the failure of the main library
2 can be used in local or remote
3 affect the performance of the main library
LGWR and AFFIRM, synchronous log write process to write to disk REDO DATA, DISK finished in the former, not the user control, as well as the main library of online logs may not be available in the archive prior to the completion of

ARCH and AFFIRM ARCn process REDO DATA synchronous write to disk, archiving operations that may occur a long time, the main library in the archive of the online logs may not be completed before the use of the log.
ASYNC and AFFIRM, the performance will not be affected.

Second, ALTERNATE
Role: When the original archive destination fails, you can use after the meeting but if the REOPEN parameter O is not the case, ALTERNATE will not be available.
MAX FAILURE if the value is 0, when the implementation of the specified number of retries after a failure, ALTERNATE to prepare the opening, therefore, ALTERNATE and REPOPEN will not conflict (REOPEN not to 0)

Usage:
ALTERNATE is optional, if not set, the log transport services will not be able to automatically switch archive path is not available if the original path you can specify a ALTERNATE for each LOG_ARCHIVE_DEST, but can share the same ALTERNATE
LOG_ARCHIVE_DEST_1 = 'LOCATION = / disk1 MANDATORY ALTERNATE = LOG_ARCHIVE_DEST_2'
LOG_ARCHIVE_DEST_STATE_1 = ENABLE
LOG_ARCHIVE_DEST_2 = 'LOCATION = / disk2 MANDATORY'
LOG_ARCHIVE_DEST_STATE_2 = ALTERNATE
LOG_ARCHIVE_DEST_1 = 'LOCATION = / disk1 MANDATORY'
LOG_ARCHIVE_DEST_STATE_1 = ENABLE
LOG_ARCHIVE_DEST_2 = 'SERVICE = stby1_path1 OPTIONAL ALTERNATE = LOG_ARCHIVE_DEST_3'
LOG_ARCHIVE_DEST_STATE_2 = ENABLE
LOG_ARCHIVE_DEST_3 = 'SERVICE = stby1_path2 OPTIONAL'
LOG_ARCHIVE_DEST_STATE_3 = ALTERNATE
Three ARCH and LGWR

Role: the use of the log transport services ARCH or LGWR,
The default is ARCH
Note that if you change the current process of archiving, for example, from ARCn to LGWR, the only log switch. Change to take effect.
LOG_ARCHIVE_DEST_3 = 'SERVICE = denver LGWR'
LOG_ARCHIVE_DEST_STATE_3 = ENABLE

Four DB_UNIQUE_NAME

If the path marked only the use of sub-parameters are usually set up LOG_ARCHIVE_CONFIG = DG_CONFIG () to match the two, as well as documents and parameters must be consistent use of this parameter is to clear the main library and the Treasury prepared to use that path

DB_UNIQUE_NAME = boston
LOG_ARCHIVE_CONFIG = 'DG_CONFIG = (chicago, boston, denver)'
LOG_ARCHIVE_DEST_1 = 'LOCATION = / arch1 /
VALID_FOR = (ALL_LOGFILES, ALL_ROLES)
DB_UNIQUE_NAME = boston '
LOG_ARCHIVE_DEST_2 = 'SERVICE = Sales_DR
VALID_FOR = (ONLINE_LOGFILES, PRIMARY_ROLE)
DB_UNIQUE_NAME = chicago '

5, DELAY
Role:
Provisions: REDO data preparation and application of database archiving is not the default time delay
The DELAY attribute is optional. By default there is no delay.

The DELAY attribute indicates the archived redo log files at the standby destination are
not available for recovery until the specified time interval has expired.
The time interval is expressed in minutes, and it starts
when the redo data is successfully transmitted to, and archived at, the standby site.

The DELAY attribute may be used to protect a standby database from corrupted or
erroneous primary data. However, there is a tradeoff because during failover
it takes more time to apply all of the redo up to the point of corruption.

The DELAY attribute does not affect the transmittal of redo data to a standby destination.

If you have real-time apply enabled, any delay that you set will be ignored.

Changes to the DELAY attribute take effect the next time redo data is archived (after a log switch).
In-progress archiving is not affected.

You can override the specified delay interval at the standby site, as follows:

For a physical standby database:

SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE NODELAY;

For a logical standby database:

SQL> ALTER DATABASE START LOGICAL STANDBY APPLY NODELAY;

Examples:
LOG_ARCHIVE_DEST_1 = 'LOCATION = / oracle / dbs /'
LOG_ARCHIVE_DEST_STATE_1 = ENABLE
LOG_ARCHIVE_DEST_2 = 'SERVICE = stbyB LGWR SYNC AFFIRM'
LOG_ARCHIVE_DEST_STATE_2 = ENABLE
LOG_ARCHIVE_DEST_3 = 'SERVICE = stbyC DELAY = 120'
LOG_ARCHIVE_DEST_STATE_3 = ENABLE

6, location and service
Each path must be named or through local service

Example 1 Specifying the LOCATION Attribute

LOG_ARCHIVE_DEST_2 = 'LOCATION = / disk1/oracle/oradata/payroll/arch /'
LOG_ARCHIVE_DEST_STATE_2 = ENABLE
Example 2 Specifying the SERVICE Attribute

LOG_ARCHIVE_DEST_3 = 'SERVICE = stby1'
LOG_ARCHIVE_DEST_STATE_3 = ENABLE

7, MANDATORY and OPTIONAL

MANDATORY: online log reused must be prepared by the successful archiving
OPTIONAL: online log can be prepared before reuse, success does not require default DESTINATION for archiving OPTIONAL
You must have at least one local destination, which you can declare OPTIONAL or MANDATORY.

At least one local destination is operationally treated as mandatory, because the minimum value for the LOG_ARCHIVE_MIN_SUCCEED_DEST parameter is 1.

The failure of any mandatory destination, including a mandatory standby destination, makes the LOG_ARCHIVE_MIN_SUCCEED_DEST parameter irrelevant.

The LOG_ARCHIVE_MIN_SUCCEED_DEST parameter value cannot be greater than the number of mandatory destinations plus the number of optional local destinations.

These attributes do not affect the data protection mode for the destination.

The BINDING column of the V $ ARCHIVE_DEST fixed view specifies how failure affects the archival operation

Examples

The following example shows the MANDATORY attribute:

LOG_ARCHIVE_DEST_1 = 'LOCATION = / arch / dest MANDATORY'
LOG_ARCHIVE_DEST_STATE_1 = ENABLE
LOG_ARCHIVE_DEST_3 = 'SERVICE = denver MANDATORY'
LOG_ARCHIVE_DEST_STATE_3 = ENABLE