The SOA is the specific record type found in every zone and contains information that identifies the sever primarily responsible for the zone as well as some operational properties for the zone.
Explanation:
The Start of Authority Records (SOA) has the following information they are
Serial Number: This number is used to find when zonal information should be replicated.
Responsible person: The Email address of a person is responsible for managing the zone.
Refresh Interval: It specifies how often a secondary DNS server tries to renew its zone information.
Retry Interval: It specifies the amount of time a secondary server waits before retrying the zone information has failed.
Expires After: IT specifies the amount of time before a secondary server considers its zone data if it can't contact with the primary server.
Minimum TTL: It specifies the default TTL value for a zone data when a TTL is not supplied.
Answer:
// program in Python to check perfect number
#function to find number is perfect or not
def is_Perfect_Number(n):
#total variable
tot = 1
i = 2
#sum of all divisor of number
while i*i<=n:
if n%i==0:
tot = tot + i + n/i
if tot == n and n != 1:
return 1
i = i+1
return 0
#read until user enter a perfect number
while True:
#read integer
num = int(input("Input an integer: "))
#call the function
if(is_Perfect_Number(num)):
print(num,"is perfect number")
#if perfect number break
break
else:
print(num,"is not a perfect number")
#ask again
print("try again.")
Explanation:
Read number from user and then call the function is_Perfect_Number() with parameter "num".This will find the sum of all divisor of number.If sum is equal to number then it will return 1 else return 0.If the number is not perfect then it will again ask to enter a number until user enter a perfect number.
Output:
Input an integer: 24
24 is not a perfect number
try again.
Input an integer: 28
28 is perfect number
Answer
To find mean of data add all the numbers in the set of data and divide the sum by the number of addends.
To find range, identify the difference between the highest value and lowest value in the set of data.
Explanation
Mean, mode, median and range are the primary measurements used to get the measures of central tendencies. To get the mean and range; first arrange the data in an ascending order, then identify the highest value and the lowest value in the set. The difference between these two data values gives the range of the set of values. For the mean, add all the set of values and then divide their sum with the number of values in the set of data.
Answer:
following types of databases available in the market −
Centralised database.
Distributed database.
Personal database.
End-user database.
Commercial database.
NoSQL database.
Operational database.
Relational database.
Cloud database.
Object-oriented database.
Graph database
