What are the constraints ?

Table Constraints define rules regarding the values allowed in columns and are the standard mechanism for enforcing integrity. SQL Server 2000 supports five classes of constraints. NOT NULL , CHECK, UNIQUE, PRIMARY KEY, FOREIGN KEY.

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What is the purpose of UPDATE STATISTICS?

Updates information about the distribution of key values for one or more statistics groups (collections) in the specified table or indexed view.

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How can I enforce to use particular index?

You can use index hint (index=index_name) after the table name. SELECT au_lname FROM authors (index=aunmind).

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What is session hijacking?

If you application is not very secure then it is possible to get the access of system after acquiring or generating the authentication information. Session hijacking refers to the act of taking control of a user session after successfully obtaining or generating an authentication session ID. It involves an attacker using captured, brute forced or reverse-engineered session IDs to get a control of a legitimate user's Web application session while that session is still in progress.

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What information that the ServletResponse interface gives the servlet methods for replying to the client?

It Allows the servlet to set the content length and MIME type of the reply.
Provides an output stream, ServletOutputStream and a Writer through which the servlet can send the reply data.

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What information that the ServletRequest interface allows the servlet access to?

Information such as the names of the parameters passed in by the client, the protocol (scheme) being used by the client, and the names of the remote host that made the request and the server that received it.

The input stream, ServletInputStream.Servlets use the input stream to get data from clients that use application protocols such as the HTTP POST and PUT methods.

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When a servlet accepts a call from a client, it receives two objects- What are they?

ServeltRequest: Which encapsulates the communication from the client to the server.

ServletResponse: Which encapsulates the communication from the servlet back to the client.

ServletRequest and ServletResponse are interfaces defined by the javax.servlet package.

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