_________ maximum number of IP addresses that can be assigned to host on a local subnet that uses the subnet mask 255. 255. 255. 224.
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Solution
No. of host will be 25– 2 = 30
5 is the number of host bits in this subnet.
Two alternative packages A and B are available for processing a database having 10k records. Package A required 0.0001 n2 time unit and package B require 10n log10n time unit to process n records. The smallest value of K for which package B will be preferred over A is _______
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Solution
\(\frac{10n\: log_{10}n}{0.0001n^{2}}=\frac{10log10}{0.001} \approx \: 10^{6}\)
Therefore value of K come out to be 6.
Given a relation R(w, x) and S(y, z) the result generated by query below is same as R if SELECT DISTINCT w, x FROM R, S
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Solution
Its given in the questions that the result set of the query should be same as that of the relational table "r" since It should be same as that of "r". It should not have any duplication is and we know that the Cartesian product of two will be empty if any of the two sets is empty, hence s should be non empty.
Given the following two statements :
S1: Every table with two single-valued attributes is in 1NF,2NF,3NF and BCNF
S2: AB→C, D →E,E→C is a minimal cover for the set of functional dependencies AB→C, D→E, AB→E, E→C.
Which one of the following is CORRECT?
Consider the following databases and answer the question below.
1.Update Project J1 set City to Allahabad.
2.Update Part P3 set P# to P4.
Are the above queries accepted or rejected?
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Solution
Query 1 update the City to Allahabad where J# is J1. It is valid, so it is accepted.Query 2 tries to update the table Part and P# to P4 which is invalid, so it is rejected.
Consider a database for employee as shown below EMP (EMPNO, ENAME, JOB, HIREDATE, SAL, DEPTNO).The query that list all employees who are working in department 30 and who earn more than all employees working in department 30 is
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Solution
The subquery
select SAL from EMP where DEPTNO = 30 Find the salary of all employee who are working in department 30, and SAL > all (select SAL from EMP where DEPTNO = 30).Find the maximum of the result given by subquery.
Which of the following technique is used in contiguous allocation of memory ?
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Solution
Forcontiguous allocation of memory we use first fit, bestfit and worst fit algorithms
Which one of the following is true?
The sequence________ is an optimal non-preemptive scheduling sequence for the following jobs which leaves the CPU idle for _________ unit(s) of time.
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Solution
Sequence is {3, 2, 1} and CPU idle time is 1 unit.It we use FIFO then CPU idle time will be one but after 9 unit time we get only 1 complete job while if we use SJF then CPU idle time will be one but weget 2 complete jobs after only 7 unit time
Consider the following set of processes with the arrival times and the CPU burst time in milli-seconds.
What is the average turn around time for these processes with the preemptive shortest remaining time first scheduling algorithm?
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Solution
Process will be executed as
Turn around time of P1= 12 – 0 = 12
Turn around time of P2= 4 – 1 = 3
Turn around time of P3= 8 – 2 = 6
Turn around time of P4= 5 – 4 = 1Average turn around time =\(\frac{12+3+6+1}{4}=5.5\)