Optimizing Oracle RAC Database Recovery- A Guide to Adjusting db_recovery_file_dest_size

How to Alter db_recovery_file_dest_size in RAC

Oracle Real Application Clusters (RAC) is a powerful technology that allows multiple instances to access a single database, providing high availability and scalability. One of the crucial parameters in RAC is db_recovery_file_dest_size, which determines the size of the recovery area. In this article, we will discuss how to alter db_recovery_file_dest_size in RAC and the best practices to follow.

1. Understanding db_recovery_file_dest_size

The db_recovery_file_dest_size parameter specifies the maximum size of the recovery area, which is a disk location where Oracle stores online redo logs, archived redo logs, and flashback logs. This parameter is important because it affects the overall performance and availability of the RAC database.

2. Prerequisites for altering db_recovery_file_dest_size

Before altering the db_recovery_file_dest_size parameter, ensure that you have the following prerequisites:

– Oracle Database Administrator (DBA) privileges.
– Access to the RAC environment.
– Knowledge of the current size of the recovery area and the available disk space.

3. Steps to alter db_recovery_file_dest_size in RAC

To alter the db_recovery_file_dest_size parameter in RAC, follow these steps:

1. Log in to one of the RAC instances as a DBA.
2. Connect to the RAC database using SQLPlus or another database client.
3. Execute the following command to change the db_recovery_file_dest_size parameter:

“`sql
ALTER SYSTEM SET db_recovery_file_dest_size = scope = both;
“`

Replace `` with the desired size in bytes. For example, to set the recovery area size to 10GB, use:

“`sql
ALTER SYSTEM SET db_recovery_file_dest_size = 10G scope = both;
“`

4. Verify the change by querying the parameter:

“`sql
SELECT name, value FROM v$parameter WHERE name = ‘db_recovery_file_dest_size’;
“`

4. Best practices for altering db_recovery_file_dest_size

– Ensure that the new size is large enough to accommodate the recovery needs of the RAC database.
– Check the available disk space before increasing the db_recovery_file_dest_size parameter.
– Consider the potential impact on the system’s performance when altering the parameter.
– Monitor the recovery area regularly to ensure it is not running out of space.
– Use the `ALTER SYSTEM` command with the `scope = both` option to ensure the change is applied to all instances in the RAC environment.

5. Conclusion

Altering the db_recovery_file_dest_size parameter in RAC is a critical task that requires careful planning and execution. By following the steps and best practices outlined in this article, you can ensure that your RAC database remains highly available and performs optimally.