SQL Interview Questions -7

101. What does the term downsizing refer to ?

A host based application is re-engineered to run in smaller or LAN based environment.

102. What is event trigger ?

An event trigger, a segment of code which is associated with each event and is fired when the event occurs.

103. Why do stored procedures reduce network traffic ?

When a stored procedure is called, only the procedure call is sent to the server and not the statements that the procedure contains.

104. What are the types of processes that a server runs ?

Foreground process and Background process.

105. What is a event handler ?

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

106. What is an integrity constraint ?

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

107. What are the various uses of database triggers ?

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

108. What is a transaction ?

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.

109. Why are the integrity constraints preferred to database triggers ?

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

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

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

111. What are the three components of a client server model ?

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

112. What are the advantages of client/server model ?

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

113. What are the disadvantages of the client/server model ?

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

114. What are the different topologies available for network ?

Star,
Bus,
Ring.

115. What is the first work of Client process ?

A client process at first establishes connection with the Server.

115. What are the responsibilities of a Server ?

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

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

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

117. Give some examples of standard API??s ?

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

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

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

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

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

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

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