The method for Manually processing log v $ archive_GAP in oracle dataguard is called dataguardgap.

The method for Manually processing log v $ archive_GAP in oracle dataguard is called dataguardgap.

After 9i, the oracle slave uard standby database generally does not need to manually process the lost logs. FAL will automatically help us with the loss. The following example shows how to manually process the lost logs:

1. What logs are lost in the standby database and are not applied to the standby database?

 SQL> select * from V$ARCHIVE_GAP;  THREAD# LOW_SEQUENCE# HIGH_SEQUENCE#---------- ------------- --------------     1     9873    9876

We can see that the four archive logs from 9873 to 9876 are lost,

2. We found the four archive logs in the master database and sent them to the archive directory of the slave database;

3. register the slave Database

alter database register logfile '/oracle/app/oracle/archive/1_9873_629923600.arc';system alertedalter database register logfile '/oracle/app/oracle/archive/1_9874_629923600.arc';system alertedalter database register logfile '/oracle/app/oracle/archive/1_9875_629923600.arc';system alertedalter database register logfile '/oracle/app/oracle/archive/1_9876_629923600.arc';system alerted

4. Check the database logs to see if the logs are applied.

Thu Apr 8 15:55:17 2010Media Recovery Log /oracle/app/oracle/archive/1_9873_629923600.arcMedia Recovery Log /oracle/app/oracle/archive/1_9874_629923600.arcMedia Recovery Log /oracle/app/oracle/archive/1_9875_629923600.arcMedia Recovery Log /oracle/app/oracle/archive/1_9876_629923600.arc

Or query the view.

V $ archived_log applied field

5. Check whether the standby database has a log GAP.

SQL> select * from V$ARCHIVE_GAP;

If no row is selected, the archive log is not lost.

For oracle dataguard?

1. How was the slave database initially built? Can I directly use the Cold Standby master database as the standby database?
There is a complete step, but the standby database can be used instead of cold backup.
2. Do the system parameter configurations of the slave database must be consistent with those of the master database?
Some? Too general. Most parameters are consistent, except for those that must be modified.
2. The slave database directly reads the archive logs of the master database and then updates the database. What should I do if the update fails due to exceptions during the update process?
It can also be a STANDBY log, that is, redo. In different STANDBY configuration modes, REDO or ARCH may be used,
Failure processing is also different in the same mode. In particular, You can manually apply logs to maintain synchronization with the master database.
3. What is called dual-host hot standby?
No. In the past, the hot standby mechanism often used to be considered as RAC. DATAGUARD is commonly used for remote disaster recovery solutions.

What is the difference between oracle distributed uard and oracle active distributed uard?

Dataguard is a database disaster tolerance model. It refers to a database device that runs in a remote place outside of a normal production environment (with its own independent database magnetic array ), if data changes occur in the production environment, the changed data operations are synchronized from the production environment in real time through dataguard to ensure data consistency in the production environment and disaster recovery environment. If the production environment database is paralyzed, the disaster recovery environment is taken over.
Data Guard can open the database in read-only mode, but the process of Media rediscovery using logs for Data Synchronization stops. If the physical backup database is in the Recovery process, the database cannot open the query, that is to say, the log application and read-only open are mutually exclusive.
The Active Data Guard feature released in Oracle 11g solves this conflict. When using logs to restore Data, you can open the database in read-only mode, users can perform query and report operations on the standby database, which is similar to the functions of the Logical Data Guard standby database (query function). However, data Synchronization is more efficient and requires less hardware resources. In this way, the hardware resources of the physical backup database can be used to a greater extent.