多項(xiàng)選擇題

Which two statements are true regarding B-tree indexs（）

A.The leaf blocks in the index are doubly linked.
B.The leaf node stores a bitmap for each key value.
C.The rows with NULL value in key columns also have entries in the index.
D.The deletion of a row from the table causes a logical deletion in index leaf block and the space becomesavailable for the new leaf entry

你可能感興趣的試題

單項(xiàng)選擇題

Given below is a list of scenarios：
1） A user terminates his session abnormally.
2） The connection between the server and the client application terminates because of a network failure.
3） A schema is accidentally dropped.
4） The tablespace is accidentally dropped from the database.
5） The hard disk gets corrupted and the data files in the disk are lost.
6） The database instance abnormally shuts down because of power failure.
Which scenarios require DBAintervention to perform recovery（）

A.1， 3， and 6
B.4， 5， and 6
C.3， 4， and 5
D.1， 2， and 6

單項(xiàng)選擇題

You are using flat files as the data source for one of your data warehousing applications. To optimize the application performance， you plan to move the data from the flat files to clustered tables in an Oracle database.While migrating the data， you want to have minimal impact on the database performance and optimize the dataload operation.
Which method would you use to load data into the Oracle database（）

A.Use the external table population.
B.Use the Oracle Data Pump export and import utility.
C.Use the conventional path data load of the SQL*Loader utility.
D.Use the INSERT INTO...SELECT command to load the data