To answer this question, you need to understand the components required to connect to an Oracle database using SQL*Plus.

Let's go through each option to understand why it is correct or incorrect:

Option A) The SQL*Plus Keyword - This option is incorrect because you need to specify the SQL*Plus keyword, such as "sqlplus", to indicate that you want to use SQL*Plus for database connection.

Option B) The username - This option is correct because you must specify a valid username to connect to the Oracle database. The username identifies the user account that you want to use for the connection.

Option C) The password - This option is correct because you must provide the correct password associated with the specified username to establish a successful connection to the Oracle database.

Option D) The database name - This option is incorrect because you must specify the database name as part of the connection information. The database name identifies the specific Oracle database you want to connect to.

The correct answer is D) The database name. This option does not indicate a component you must specify when logging into the Oracle database using SQL*Plus.

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To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) The UNIQUE constraint does not permit a null value for the column. This option is correct. The UNIQUE constraint ensures that each value in the column is unique. It also does not permit a null value for the column, meaning that the column must have a non-null value for each row.

Option B) A UNIQUE index gets created for columns with PRIMARY KEY and UNIQUE constraints. This option is incorrect. While it is true that a UNIQUE index is created for columns with UNIQUE constraints, it is not true for columns with PRIMARY KEY constraints. A PRIMARY KEY constraint automatically creates a unique index, but a UNIQUE constraint creates a separate unique index.

Option C) The PRIMARY KEY and FOREIGN KEY constraints create a UNIQUE index. This option is incorrect. While it is true that a PRIMARY KEY constraint automatically creates a unique index, a FOREIGN KEY constraint does not create a unique index. A FOREIGN KEY constraint is used to establish a relationship between two tables.

Option D) The NOT NULL constraint ensures that null values are not permitted for the column. This option is correct. The NOT NULL constraint ensures that the column must have a non-null value for each row. It does not allow null values to be inserted into the column.

The correct answer is A and D. These options are correct because the UNIQUE constraint does not permit a null value for the column, and the NOT NULL constraint ensures that null values are not permitted for the column.

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To answer this question, let's go through each option to understand which constraint can be defined only at the column level:

Option A) Unique - The unique constraint can be defined at both the column level and the table level. So, this option is incorrect.

Option B) Not null - The not null constraint can only be defined at the column level. This option is correct.

Option C) Check - The check constraint can be defined at both the column level and the table level. So, this option is incorrect.

Option D) Primary key - The primary key constraint can be defined at both the column level and the table level. So, this option is incorrect.

Option E) Foreign key - The foreign key constraint can be defined at both the column level and the table level. So, this option is incorrect.

The correct answer is option B) Not null. This constraint can only be defined at the column level.

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To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) SELECT ADD_MONTHS(MAX(hire_Date), 6) FROM EMP; This option calculates the maximum hire date from the EMP table and adds 6 months to it using the ADD_MONTHS function. The result is a date value, not a numeric value.

Option B) SELECT ROUND(hire_date) FROM EMP; This option rounds the hire_date column values to the nearest whole number. The result is a date value, not a numeric value.

Option C) SELECT sysdate-hire_date FROM EMP; This option subtracts the hire_date column values from the current date (sysdate) using the minus operator. The result of this subtraction operation is a numeric value representing the number of days between the hire date and the current date.

Option D) SELECT TO_NUMBER(hire_date + 7) FROM EMP; This option adds 7 days to the hire_date column values and then converts the result to a numeric value using the TO_NUMBER function. The result is a numeric value.

The correct answer is option C. This option returns a numeric value because it calculates the number of days between the hire date and the current date.

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To answer this question, you need to understand the concept of object privileges and views.

A view is a virtual table that is based on the result of a query. It allows you to retrieve data from one or more tables as if it were a single table. When granting privileges on a view, you can specify which operations can be performed on the view.

Let's go through each option to understand which object privileges can be granted on a view:

Option A) None - This option is incorrect because object privileges can be granted on a view.

Option B) DELETE, INSERT, SELECT - This option is incorrect because it does not include the UPDATE privilege, which can be granted on a view.

Option C) ALTER, DELETE, INSERT, SELECT - This option is incorrect because it does not include the UPDATE privilege, which can be granted on a view.

Option D) DELETE, INSERT, SELECT, UPDATE - This option is correct because it includes all the object privileges that can be granted on a view. With these privileges, you can perform operations such as deleting, inserting, selecting, and updating data on the view.

The correct answer is option D.

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To answer this question, we need to understand the concept of constraints in a database and how they relate to indexes.

Constraints are rules that are applied to columns or tables in a database to enforce data integrity. They ensure that the data stored in the database follows certain rules or conditions.

An index, on the other hand, is a data structure that improves the speed of data retrieval operations on a database table. It allows for faster searching and sorting of data.

In Oracle Server, there are several types of constraints that can be defined on a table, including:

A. Not null - This constraint ensures that a column cannot have a null value. B. Primary key - This constraint ensures that a column or a combination of columns uniquely identifies each row in a table. It implicitly creates a unique index on the primary key column(s). C. Foreign key - This constraint ensures that values in a column (or a set of columns) of one table match the values in another table's primary key or unique key column(s). D. Check - This constraint ensures that the values in a column meet a specific condition or set of conditions. E. Unique - This constraint ensures that the values in a column (or a set of columns) are unique across all rows in a table. It implicitly creates a unique index on the unique constraint column(s).

Based on the given options, the two constraints for which the Oracle Server implicitly creates a unique index are:

B. Primary key - This constraint ensures that a column or combination of columns uniquely identifies each row in a table. The Oracle Server implicitly creates a unique index on the primary key column(s). E. Unique - This constraint ensures that the values in a column (or a set of columns) are unique across all rows in a table. The Oracle Server implicitly creates a unique index on the unique constraint column(s).

Therefore, the correct answer is B and E.

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