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Oracle rac interview questions

1 What do you understand by cache fusion?

The combination of data blocks coming straight from remote database caches and getting shipped to the local nodes so that the requirements for doing a transaction such as a DDL or a DML can be fulfilled.

2  What are the uses of RAC?

RAC or Real Application Clusters are used to support all the software where aspects such as high availability and grouped level of clustering are expected. Other uses of RAC are:

• Detection of any unwanted results or errors
• Reliability
• Continuous Operations
• Recoverability

3 What is the ASM Metadata backup technique?

Md_backup is the command which can be used to take ASM metadata backup. It is also used to restore the disk group based configurations if a storage loss for ASM disk group is encountered.

4 Explain split brain?

It is related with the miscommunication among nodes of a cluster. Those database nodes then continue their processing and make relevant changes in their data blocks on their own. In case multiple instances are responsible for modifying one block, the data blocks are not able to synchronize among themselves and those writes will be done by others for the same block. This entire process is called the split brain.

5 Discuss OEM tools?

• Database Control
• Grid Control