Propose an improvement that permits bitmap indices to maintain only n ? 1 bit vectors in order to represent attributes that can take n di?erent values. Discuss the change that is needed to perform selection, especially in case of a multiattribute selection that requires a Boolean operation on multiple bit vectors.

What will be an ideal response?


Consider an attribute, A, that can take n values. We can use n ? 1 vectors for the ?rst n ? 1 values of A. For the n-th value, we can always reconstruct the corresponding bit vector using the following Boolean expression: vector1 .. . vectorn 1. This vector has 1 exactly for the rows where A has the value that is di?erent from any of the ?rst n ? 1 values.

Computer Science & Information Technology

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(b)









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Computer Science & Information Technology

If your firewall allowed only the machine with the IP address 192.168.1.1 to send email outside the network, how would you instruct the local copy of sendmail to use this server as a relay?

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Computer Science & Information Technology

The ____ Tool increases contrast along edges to add sharpness.

a. Sharpen b. Exposure c. Clarity d. Edge

Computer Science & Information Technology

Describe how to map a network drive.

What will be an ideal response?

Computer Science & Information Technology