Answer:
a. True
Explanation:
The three tiers in a three-tier architecture are:
Presentation Tier: Occupies the top level and displays information related to services available on a website. This tier communicates with other tiers by sending results to the browser and other tiers in the network.
Middle Tier: Also called the application tier, logic tier, business logic or logic tier, this tier is pulled from the presentation tier. It controls application functionality by performing detailed processing.
Data Tier: Houses database servers where information is stored and retrieved. Data in this tier is kept independent of application servers or business logic.
Inaccurate and misleading
Answer:
d. public myClass( ) {. . .}
Explanation:
A constructor is a special method that is called when an object of a class is created. It is also used to initialize the instance variables of the given class. A class may have one or more constructors provided that these constructors have different signatures. A class that does not have a constructor explicitly defined has a default parameterless constructor.
Having said these about a constructor, a few other things are worth to be noted by a constructor.
i. In Java, a constructor has the same name as the name of its class.
For example, in the given class <em>myClass</em>, the constructor(s) should also have the name <em>myClass</em>.
ii. A constructor does not have a return value. It is therefore wrong to write a constructor like this:
<em>public void myClass(){...}</em>
This makes option a incorrect.
iii. When a constructor with parameters is defined, the default parameterless constructor is overridden. This might break the code if some other parts of the program depend on this constructor. So it is advisable to always explicitly write the default parameterless constructor.
This makes option d a correct option.
Other options b and c may also be correct but there is no additional information in the question to help establish or justify that.
Answer:
Hi Riahroo! This is a good question on the concept of relational databases.
We can normalize the relations as follows:
Flight
(flightnumber (unique), flighttime, airline_id, departure_city, arrival_city, passenger_id, pilot_id, airplane_id)
has_one_and_belongs_to :airline
has_many :passengers
has_one :pilot
Itinerary(passenger_id, flight_id)
Belongs_to
Passenger_details
(passengername (unique), gender, date_of_birth)
has_many :flights
Pilot
(pilotname (unique), gender, date_of_birth)
has_many :flights
airline(airlinename)
airplane(planeID, type, seats))
Explanation:
To normalize a relation, we have to remove any redundancies from the relationships between database objects/tables and simplify the structure. This also means simplifying many-to-many relationships. In this question, we see there is a many-to-many relationship between flights and passengers. To resolve this we can introduce a join table which simplifies this relationship to a one-to-many between the objects.
Answer: Copy the files from the NAS to an S3 bucket with the One Zone-IA class
Explanation:
Th one Zone -IA class with S3 bucket has reduced cost but offers the same durability for which the files needs to be copied from NAS to access them faster.
