Question 1 :
What are the different types of segments?
Data segment, index segment, rollback segment and temporary segment.
Question 2 :
What is a data segment?
Each non-clustered table has a data segment. All of the table's data is stored in the extents of its data segment. Each cluster has a data segment. The data of every table in the cluster is stored in the cluster's data segment.
Question 3 :
What is an index segment?
Each index has an index segment that stores all of its data.
Question 4 :
What is rollback segment?
A database contains one or more rollback segments to temporarily store "undo" information.
Question 5 :
What are the uses of rollback segment?
To generate read-consistent database information during database recovery and to rollback uncommitted transactions by the users.