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databases Online Quiz - 152

Description: databases Online Quiz - 152
Number of Questions: 20
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Tags: databases
Attempted 0/20 Correct 0 Score 0

When is a Cartesian product formed?

  1. When a join condition is omitted.

  2. When a join condition is invalid.

  3. All rows in the first table are joined to all rows in the second table.

  4. All of the above.


Correct Option: D

A Non equi-join is a join condition that does not contain an equality operator.

  1. True

  2. False


Correct Option: B

SYSDATE is a date function that returns the current database server date and time.

  1. True

  2. False


Correct Option: B

Which keyword used in DML statements prohibits you from changing rows that are not in the sub-query?

  1. CHECK keyword

  2. WITH CHECK keyword

  3. WITH CHECK OPTION keyword

  4. None of the Above


Correct Option: C

Explicit Defaults can be used in

  1. INSERT statement

  2. UPDATE statement

  3. Both of the Above

  4. None of the Above


Correct Option: C

MERGE statement

  1. Avoids separate updates

  2. ncreases performance and ease of use

  3. Is useful in data warehousing applications

  4. All of the above


Correct Option: D

Database transactions end with

  1. COMMIT or ROLLBACK

  2. A DDL or DCL statement executing

  3. USER exiting iSQL*Plus or System crash

  4. Any one of the above


Correct Option: D

You can update more than 1 row in a table with one update syntax

  1. True

  2. False


Correct Option: B

Which is not a group function?

  1. Count

  2. Avg

  3. Total

  4. Max


Correct Option: C

You can use Avg or Sum group functions for any numeric data

  1. True

  2. False


Correct Option: B

COUNT(DISTINCT expr) returns

  1. No. of rows in a table

  2. No. of rows with non-null values of the expr

  3. No. of distinct non-null values of the expr

  4. None of the above


Correct Option: C

All columns in the SELECT list, that are not there in the GROUP function, should be in the Group By clause

  1. True

  2. False


Correct Option: B
  1. HAVING

  2. WHERE

  3. Order By

  4. Group by


Correct Option: A
  1. Numeric data

  2. Data type

  3. Char data

  4. None of the Above


Correct Option: A
  1. All rows of the Employee table

  2. Rows of the Employee table where the set grade is ‘Y’

  3. Delete 1 row

  4. Nothing will be deleted


Correct Option: B

Character values are case insensitive

  1. True

  2. False


Correct Option: B
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