Set - 6

Question 1 :

What are the types of processes that a server runs ?

Answer :

Foreground process and Background process.


Question 2 :

What is a event handler ?

Answer :

An event handler is a routine that is written to respond to a particular event.


Question 3 :

What is an integrity constraint ?

Answer :

An integrity constraint allows the definition of certain restrictions, at the table level, on the data that is entered into a table.


Question 4 :

What are the various uses of database triggers ?

Answer :

Database triggers can be used to enforce business rules, to maintain derived values and perform value-based auditing.


Question 5 :

What is a transaction ?

Answer :

A transaction is a set of operations that begin when the first DML is issued and end when a commit or rollback is issued. BEGIN COMMIT/ROLLBACK are the boundries of a transaction.


Question 6 :

Why are the integrity constraints preferred to database triggers ?

Answer :

Because it is easier to define an integrity constraint than a database trigger.


Question 7 :

Why is it better to use an integrity constraint to validate data in a table than to use a stored procedure ?

Answer :

Because an integrity constraint is automatically checked while data is inserted into a table. A stored has to be specifically invoked.


Question 8 :

What are the three components of a client server model ?

Answer :

A Client,
A Server and
A Network/Communication software.


Question 9 :

What are the advantages of client/server model ?

Answer :

Flexibility of the system, scalability, cost saving, centralised control and implementation of business rules, increase of developers productivity, portability, improved network and resource utilization.


Question 10 :

What are the disadvantages of the client/server model ?

Answer :

Heterogeneity of the system results in reduced reliability. May not be suitable for all applications. Managing and tuning networks becomes difficult.


Question 11 :

What are the different topologies available for network ?

Answer :

Star,
Bus,
Ring.


Question 12 :

What is the first work of Client process ?

Answer :

A client process at first establishes connection with the Server.


Question 13 :

What are the responsibilities of a Server ?

Answer :

1. Manage resources optimally across multiple clients.
2. Controlling database access and security.
3. Protecting the database and recovering it from crashes.
4. Enforcing integrity rules globally.


Question 14 :

In a Client/Server context, what does API (Application Programming Interface) refer to ?

Answer :

An API, in a Client/Server context, is a specification of a set of functions for communication between the client and the server.


Question 15 :

Give some examples of standard API??

Answer :

Open Database Connectivity (ODBC),
Integrated Database Application Programming Interface (IDAPI),
XOpen
SQL/CLI


Question 16 :

What is the main advantage of developing an application using an API ?

Answer :

The application can be connected to any back end server that is supported by the API.


Question 17 :

What is the main disadvantage of developing an application using an API ?

Answer :

The application cannot use any special features of the backend server.


Question 18 :

Why is an event driven program referred to a passive program ?

Answer :

Because an event driven program is always waiting for something to happen before processing.


Question 19 :

What are the four types of events ?

Answer :

1. System Events.
2. Control Events
3. User Events
4. Other Events.


Question 20 :

What is the difference between file server and a database server ?

Answer :

A file server just transfers all the data requested by all its client and the client processes the data while a database server runs the query and sends only the query output.


Question 21 :

What is inheritance ?

Answer :

Inheritance is a method by which properties and methods of an existing object are automatically passed to any object derived from it.


Question 22 :

What are the two components of ODBC ?

Answer :

1. An ODBC manager/administrator and
2. ODBC driver.


Question 23 :

What is the function of a ODBC manager ?

Answer :

The ODBC Manager manages all the data sources that exists in the system.


Question 24 :

What is the function of a ODBC Driver ?

Answer :

The ODBC Driver allows the developer to talk to the back end database.


Question 25 :

What description of a data source is required for ODBC ?

Answer :

The name of the DBMS, the location of the source and the database dependent information.