Tag: technology

Questions Related to technology

Which three are true? (Choose three.)

technology databases

  1. A MERGE statement is used to merge the data of one table with data from another.

  2. A MERGE statement replaces the data of one table with that of another.

  3. A MERGE statement can be used to insert new rows into a table.

  4. A MERGE statement can be used to update existing rows in a table.

Show answer
Correct Option: A,C,D

AI Explanation

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

Option A) A MERGE statement is used to merge the data of one table with data from another. - This option is correct. A MERGE statement combines data from two tables based on a specified condition and updates or inserts data into a target table based on the matching condition.

Option B) A MERGE statement replaces the data of one table with that of another. - This option is incorrect. A MERGE statement does not replace the data of one table with another. It merges or updates data based on the specified condition.

Option C) A MERGE statement can be used to insert new rows into a table. - This option is correct. A MERGE statement can insert new rows into a table when a matching condition is not met during the merge operation.

Option D) A MERGE statement can be used to update existing rows in a table. - This option is correct. A MERGE statement can update existing rows in a table based on the specified condition.

Therefore, the correct answers are A, C, and D.

Which statement describes the ROWID data type?
technology databases

  1. binary data up to 4 gigabytes

  2. character data up to 4 gigabytes

  3. raw binary data of variable length up to 2 gigabytes

  4. binary data stored in an external file, up to 4 gigabytes

  5. a hexadecimal string representing the unique address of a row in its table

Show answer
Correct Option: E

A variant of computer malware whose name was influenced by Greek Mythology
technology security

  1. Chimera

  2. Trojan

  3. Hercules

  4. Hydra

Show answer
Correct Option: B

Which is a valid CREATE TABLE statement?
technology databases

  1. CREATE TABLE EMP9$# AS (empid number(2));

  2. CREATE TABLE EMP*123 AS (empid number(2));

  3. CREATE TABLE PACKAGE AS (packid number(2));

  4. CREATE TABLE 1EMP_TEST AS (empid number(2));

Show answer
Correct Option: A

Which three are true regarding the use of outer joins? (Choose three.)

technology databases

  1. You cannot use IN operator in a condition that involves an outer join

  2. You use (+) on both sides of the WHERE condition to perform an outer join

  3. You use (*) on both sides of the WHERE condition to perform an outer join

  4. You use an outer join to see only the rows that do not meet the join condition

  5. In the WHERE condition, you use (+) following the name of the column in the table without matching rows, to perform an outer join

  6. You cannot link a condition that is involved in an outer join to another condition by using the OR operator.

Show answer
Correct Option: A,E,F

AI Explanation

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

Option A) You cannot use IN operator in a condition that involves an outer join - This option is true. When using an outer join, you cannot use the IN operator in the condition that involves the outer join.

Option B) You use (+) on both sides of the WHERE condition to perform an outer join - This option is incorrect. The use of (+) syntax on both sides of the WHERE condition is used in Oracle's old outer join syntax, but it is not the recommended approach. The ANSI SQL standard syntax should be used instead.

Option C) You use () on both sides of the WHERE condition to perform an outer join - This option is incorrect. The use of () syntax on both sides of the WHERE condition is not valid for performing an outer join.

Option D) You use an outer join to see only the rows that do not meet the join condition - This option is incorrect. An outer join is used to include rows from one table that may not have a match in the other table, but it does not limit the result set to only the rows that do not meet the join condition.

Option E) In the WHERE condition, you use (+) following the name of the column in the table without matching rows, to perform an outer join - This option is true. In Oracle's old outer join syntax, you can use (+) following the name of the column in the table without matching rows to perform an outer join.

Option F) You cannot link a condition that is involved in an outer join to another condition by using the OR operator - This option is true. When using an outer join, you cannot link a condition involved in the outer join to another condition using the OR operator.

Therefore, the three true statements regarding the use of outer joins are: A. You cannot use the IN operator in a condition that involves an outer join. E. In the WHERE condition, you use (+) following the name of the column in the table without matching rows, to perform an outer join. F. You cannot link a condition that is involved in an outer join to another condition by using the OR operator.

Which constraint can be defined only at the column level?

technology databases

  1. UNIQUE

  2. NOT NULL

  3. CHECK

  4. PRIMARY KEY

Show answer
Correct Option: B

AI Explanation

To answer this question, you need to understand the different constraints that can be defined in a database. Let's go through each option to understand why it is correct or incorrect:

Option A) UNIQUE - This constraint can be defined at both the column level and the table level. It ensures that the values in a column are unique across all rows in the table.

Option B) NOT NULL - This constraint can only be defined at the column level. It ensures that the column cannot contain any null values.

Option C) CHECK - This constraint can be defined at both the column level and the table level. It allows you to specify a condition that must be met for the values in the column or table.

Option D) PRIMARY KEY - This constraint can be defined at both the column level and the table level. It ensures that the values in the column or combination of columns are unique and not null. It also automatically creates a unique index on the column or combination of columns.

The correct answer is B) NOT NULL. This constraint can only be defined at the column level, ensuring that the column cannot contain any null values.

Which best describes an inline view?
technology databases

  1. a schema object

  2. a subquery that can contain an ORDER BY clause

  3. another name for a view that contains group functions

  4. a subquery that is part of the FROM clause of another query

Show answer
Correct Option: D

The default value the lpad function takes is
technology programming languages

  1. a space

  2. an asterisk

  3. The default value is not optional

  4. None of the above

Show answer
Correct Option: A

Which of the following is true about add_months
technology programming languages

  1. we can pass a numerical value in first parameter

  2. we can pass a negative value in second parameter

  3. Both a & b

  4. None of the above

Show answer
Correct Option: B

What does OFA stands for ?
technology programming languages

  1. Oracle Flexible Architecture

  2. Oracle Financials Applications

  3. Optimal Flexible Architecture

  4. None of the above

Show answer
Correct Option: C