1.
What is wrong with these statements?
Correct Answer
B. Select first-name into first_name1 from emp
Explanation
The given statements are incorrect because they contain syntax errors. In the first statement, "cursor cursor_name is" is not a valid syntax. It should be "cursor cursor_name is select...". In the second statement, "first-name" should be written as "first_name" without the hyphen. Lastly, the third statement is not needed as it is just a null statement.
2.
Which will delete records from the table which cant be rolled back?
Correct Answer
C. Truncate
Explanation
Truncate is the correct answer because it is a DDL (Data Definition Language) command that is used to delete all the records from a table. Unlike the delete command, the truncate command cannot be rolled back, meaning that once the truncate command is executed, the data cannot be recovered. The drop command is used to delete an entire table, not just its records. Therefore, the truncate command is the only option that fits the given criteria.
3.
Which one of the following is not a shutdown command for a database?
Correct Answer
A. Shutdown partial
Explanation
The correct answer is "Shutdown partial" because it is not a valid shutdown command for a database. The other options, "Shutdown Transactional," "Shutdown normal," and "Shutdown Immediate," are valid commands that can be used to shut down a database. "Shutdown partial" does not exist as a valid command in most database management systems.
4.
System Change Number (SCN) ________________.
Correct Answer
B. Is generated for every checkpoint (CKPT) occurred
Explanation
The System Change Number (SCN) is a unique identifier that is generated for every checkpoint (CKPT) that occurs in the database. A checkpoint is a process that writes all the modified data from the database buffers to the data files on disk. The SCN is used to track the order of transactions and ensure data consistency. Therefore, the correct answer is that the SCN is generated for every checkpoint occurred.
5.
Which of the following is not an aspect of logical data model?
Correct Answer
D. Object
Explanation
The correct answer is "Object". In a logical data model, an object is not considered as an aspect. Instead, the main aspects are entities, relations, and attributes. Entities represent the real-world objects or concepts, relations define the associations between entities, and attributes describe the characteristics or properties of entities. Objects, on the other hand, are typically associated with object-oriented programming and are not directly related to logical data modeling.
6.
What does truncate do?
Correct Answer
A. Deletes all the rows and applies autocommit.
Explanation
The truncate function in this context refers to deleting all the rows in a table and applying autocommit. This means that the function will remove all the data in the table and automatically commit the changes, making them permanent. This is different from deleting rows after or before a commit, as it specifically deletes all the rows and applies the commit immediately.
7.
Which of the following are some important dynamic performance views?
Correct Answer
B. V$Database, V$Instance, V$controlfiles, V$logfiles
Explanation
The correct answer is V$Database, V$Instance, V$controlfiles, V$logfiles. These views are important dynamic performance views in a database. V$Database provides information about the database such as its name, version, and creation time. V$Instance provides information about the current instance of the database. V$controlfiles provides information about the control files of the database, which are crucial for database operation and recovery. V$logfiles provides information about the redo log files, which are used for crash recovery and instance recovery.
8.
Triggers are fired on:
Correct Answer
D. Insert, Update or Delete
Explanation
Triggers are database objects that are associated with a table and are fired automatically in response to specific events. These events include Insert, Update, or Delete operations on the table. When any of these operations are performed on the table, the trigger is triggered and its associated code is executed. Therefore, the correct answer is Insert, Update, or Delete.
9.
Which of the following is a feature of a tablespace?
Correct Answer
A. Logical storage unit used to group related data structures
Explanation
A tablespace is a logical storage unit used to group related data structures. It allows for the organization and management of database objects such as tables, indexes, and partitions. By grouping these objects together in a tablespace, it becomes easier to manage and allocate storage resources. Additionally, tablespaces provide the ability to assign different storage characteristics to different sets of data, allowing for more efficient storage management.
10.
Which of the following is not the feature of database view?
Correct Answer
C. Add portability
Explanation
The feature of adding portability is not associated with a database view. Database views are used to provide additional security by allowing users to access only specific data, hide complexity by presenting a simplified view of the data, and store complex queries for easier access. However, adding portability is not a specific feature of a database view.