模式的优势Oracle92归档模式谁都不能忽视的优势（oracle92 归档）

Oracle 9i Archivelog Mode: The Advantages You Cannot Afford to Ignore

Oracle 9i is a powerful relational database management system (RDBMS) widely used in enterprise-level applications. One of its most important features is the Archivelog mode, which enables database administrators to create a backup of the transactional data in a disk-based archive. This article will explore the advantages of the Archivelog mode and illustrate its implementation process with relevant examples.

Advantages of Archivelog Mode

1. Data Recovery: Archivelog mode provides a reliable data recovery mechanism in case the database crashes or experiences data loss due to unforeseen circumstances. The archived data can be used to restore the database to a specific point in time before the crash occurred.

2. Disaster Recovery: The archived data can also be used to recover data in case of a disaster like a fire, natural calamity, or any other disruptive event that can physically damage the hardware or disrupt the data center.

3. Transaction Log Management: Archivelog mode allows for efficient transaction log management, which means the transactional changes made to the database are recorded in a log file. This log file can be used to track changes made to the database and make sense of them during recovery.

4. Scalability: Archivelog mode is scalable to meet the growing demands of the database requirements. In case the business requirements change and the database size increases, the Archivelog mode can be used to meet the storage and backup demands.

5. Replication: Archivelog mode can be used to transfer transactional data to other databases, which can be then used for reporting and analytics purposes. This enables the use of transactional data for business intelligence.

Implementation Process

The implementation process of Archivelog mode includes the following steps:

Step 1: Ensure that the database is running in Noarchivelog mode. This can be done by issuing the following command:

SQL> select log_mode from v$database;

If the result is ‘Noarchivelog’, proceed with the next step.

Step 2: Shut down the database by issuing the following command:

SQL> shutdown immediate;

Step 3: Configure the database for Archivelog mode by creating a new initialization parameter file (pfile) and modifying the log_archive_start parameter as follows:

log_archive_start = true

Step 4: Start the database in mount mode by issuing the following command:

SQL> startup mount;

Step 5: Enable Archivelog mode by issuing the following command:

SQL> alter database archivelog;

Step 6: Start the database by issuing the following command:

SQL> alter database open;

Step 7: Verify that the database is running in Archivelog mode by issuing the following command:

SQL> select log_mode from v$database;

If the result is ‘Archive mode’, then the Archivelog mode has been successfully enabled.

Conclusion

The Archivelog mode is a critical feature of Oracle 9i RDBMS that enables robust data recovery and disaster recovery in case of data loss or disruption. It offers transaction log management, scalability, and replication features to meet the changing demands of enterprise-level applications. The implementation process of Archivelog mode is strghtforward and can be performed by following the steps outlined above. In conclusion, the advantages of Archivelog mode are too great to ignore, and its implementation is highly recommended for businesses that require a high level of data resiliency and disaster recovery capabilities.