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databases Online Quiz - 35

Description: databases Online Quiz - 35
Number of Questions: 20
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Tags: databases
Attempted 0/20 Correct 0 Score 0

What is a candidate key?

  1. Used to uniquely identify a row

  2. Alias for primary key

  3. Used to identify a column

  4. Alias for foreign key


Correct Option: A

Can I call a trigger directly called from an application?

  1. True

  2. False


Correct Option: B

A view is nothing but a ________ table or a stored query

  1. Dymanic

  2. Real

  3. Virtual

  4. Static


Correct Option: C
  1. Using COUNT

  2. Using NUM

  3. Using NUMBER

  4. Both a and c above


Correct Option: A

How do I find out all databases starting with ‘test to which I have access to?

  1. SHOW DATABASES LIKE ‘%tech%’;

  2. SHOW DATABASES LIKE ‘%tech;

  3. SHOW DATABASES LIKE ‘'tech'%’;

  4. SHOW DATABASES LIKE ‘tech%’;


Correct Option: D

Can I define multiple unique constraints on a table?

  1. True

  2. False


Correct Option: A

When do we use a HAVING clause?

  1. To limit the output of a query

  2. To limit the output of a query using an aggregate function only

  3. When GROUP by is used

  4. both b and c above


Correct Option: B

USE keyword is used to select a ___________ .

  1. Table

  2. Column

  3. Database

  4. All the above


Correct Option: C
  1. A flat file called "plan_table.txt"

  2. Oracle Table called "plan_table"

  3. Oracle Table called "plan table"

  4. A flat file called "plan_table.tbl"


Correct Option: B

What is TRUE about driving table?

  1. It's advisable to choose the driving table with maximum number of records

  2. Number of records is NOT the criteria while selecting driving table

  3. It's advisable to choose the driving table with less number of records

  4. Driving table is always the last table accessed by the Optimizer


Correct Option: C

Why one should NOT use expressions on the columns in the predicate?

  1. Optimizer will return parse error if expressions are used on columns in the predicate

  2. Optimizer does not use index if expressions are used on the columns in the predicate, even if one exists

  3. It makes no difference with / without expressions on the columns in the predicate

  4. Using expressions on the columns in the predicate won't get benefits of using Table Alias


Correct Option: B

What will be the output of- "Select 1 from dual UNION Select 'A' from dual"

  1. 1,A

  2. A

  3. Error

  4. 1


Correct Option: C

A table has the following data: [[5, Null, 10]].What will the average function return ?

  1. Null

  2. 7.5

  3. 5

  4. 10


Correct Option: B

If all the values from a cursor have been fetched and another fetch is issued,what the output will be?

  1. Error

  2. Last record

  3. First record

  4. Can't be decided.


Correct Option: B
  1. System tablespace

  2. Default tablespace for the user

  3. Users tablespace

  4. Oracle will give an error


Correct Option: B

Assuming today is Monday, 10 July 2000, what is returned by this statement: SELECT to_char(NEXT_DAY(sysdate, 'MONDAY'), 'DD-MON-RR') FROM dual?

  1. 10-JUL-00

  2. 12-JUL-00

  3. 11-JUL-00

  4. 14-JUL-00

  5. 17-JUL-00


Correct Option: E
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