Tag: databases

Quizzes (243) Questions (4862)

Questions Related to databases

Multiple choice technology databases

Evalute the follwing SQL statements? ALTER TABLE HR.EMP SET UNUSED ( MGR_ID ); which statements is true ?

  1. Any constraints defined on the MGR_ID column would be removed by the above command

  2. Any views created on the EMP table that include the MGR_ID column would have to bve dropped and re-created

  3. Any index created on the MGR_ID column would continue to exists until the DROP UNUSED COLUMNS command is executed.

  4. Any synonym existing on the EMP table would have to be re-created
Reveal answer Fill a bubble to check yourself
D Correct answer
Multiple choice technology databases

In which sceneria would you use the ROLLUP operator for expresiion or column with in a GROUPBY clause?

  1. To find the groups forming the subtotal in a row

  2. To create group-wise totals for the groups specified within a GROUPBY clause

  3. To create grouping for expressions or columns specified within a GROUPBY clause in one direction,from right to left for calculating the subtotals.

  4. To create grouping for expressions or columns specified within a GROUPBY clause in all possible direction,which is cross-tabular report for calculating the subtotals
Reveal answer Fill a bubble to check yourself
C Correct answer
Full explanation
Multiple choice technology databases

Which statement best describes the GROUPING function?

  1. used to set the order for the groups to be used for calculating the grand totals and subtotals

  2. used to form various groups to caculate totals and subtotals created using ROLLUP and CUBE operators

  3. used to specify if the NULLL value in an expresion is a stored NULL value or created by ROLLUP and CUBE

  4. used to specify the concatenated groups expressions to be used for calculating the grand totals and subtotals
Reveal answer Fill a bubble to check yourself
C Correct answer
Full explanation
Multiple choice technology databases

Given below is the SQL statements executed in a user session: CREATE TABLE product (pcode NUMBER(2) ,pname VARCHAR2(10)); INSERT INTO product VALUES (1,'PEN'); INSERT INTO product VALUES (2,'PENCIL'); SAVEPOINT A; UPDATE product SET pcode=10 where pcode=1; SAVEPOINT B; DELETE FROM product where pcode=2; COMMIT; DELETE FROM product where pcode=10; ROLLBACK TO SAVEPOINT a; which statement describes the consequences?

  1. both the DELETE statements would be rolledback

  2. No SQL statements would be rolledback

  3. only the second DELETE statements would be rolledback

  4. both the DELETE statements and the update statements would be rolledback
Reveal answer Fill a bubble to check yourself
B Correct answer
Full explanation
Multiple choice technology databases

the following are the steps for a correlated subquery ,listed in a random order: 1)the where clause of the outer query is evaluted 2)The candiadate row is fetched from the table specified in the outer query 3) The procedure is repeated for the subsequent rows of the table,till all the rows are processed. 4)Rows are returned by the inner query ,after being evaluted with the value from the candiadate row in the outer query. Identify the option that contains the steps in the correct sequences in which the oracle server evalutes a correlated subquery ?

  1. 4,2,1,3

  2. 4,1,2,3

  3. 2,4,1,3

  4. 2,1,4,3
Reveal answer Fill a bubble to check yourself
C Correct answer
Full explanation