Oracle Interview Questions and Answers Pdf Free Download - 1

Question: 1

What is the difference between database and instance?

Database is the collection of data files that contain the information of interest; whereas instance is the combination of background processes and memory structure.

Question: 2

What are the disk components?

Data files, Redo Logs, Control files, Password files and Parameter files are the disk components.

Question: 3

What is Database Writer (DBWR)?

DBWR is a background process that writes changed data blocks from buffer cache to the data file. The changed data blocks are called dirty blocks.

Question: 4

What do you mean by data consistency?

Data consistency provides a stable or consistent data to the users throughout the session.

Data consistency is maintained through rollback segments.

A rollback statements holds the data image before change; therefore, one or more session will get the same image of the data throughout the session that were reading the data while another session is updating.

Question: 5

What are the components of SGA?

SGA is used to store shared information. It includes Buffer cache, Log buffer, Shared poll, Large Pool and Java pool.