a2zinterviews

29.	What is B–tree index?
	B–tree index is the default index in Oracle. A B–tree generally indicates down tree like structure where top node generally indicates the mid value. All leaves towards the left will have lower value than the node value and all the leaves on the right will have higher value than the node value. This keeps on going until the entire set of index value is arranged in the tree structure. A B–tree structure reduces the number of look up required to search any value.
	Discuss Your Name Your Email-ID Your Answer

30.	What is an index organized table?
	Generally, a table is stored independently of any index and the index stores index value with the rowed of the table to enhance the performance of the queries. In case of index organized tables, the entire row is stored with the index value and not just the rowid.
	Discuss Your Name Your Email-ID Your Answer

31.	What permissions must be granted to users to allow them to connect to the database?
	You should grant the CONNECT permission to the user.
	Discuss Your Name Your Email-ID Your Answer

32.	How can you rebuild an index?
	An index can be rebuilt by using the ALTER INDEX <index_name> REBUILD; statement.
	Discuss Your Name Your Email-ID Your Answer