Virtual communities typically have all of the following except:
a.)currency
b.)rules of conduct
c.)games
d.)real life conduct

What is a costume plot? why is it important to a film or theater production?

Answer the following questions regarding your system by using the commands listed in this chapter. for each question, write the command you used to obtain the answer. a. what are the total number of inodes in the root filesystem? how many are currently utilized? how many are available for use? b. what filesystems are currently mounted on your system? c. what filesystems are available to be mounted on your system? d. what filesystems will be automatically mounted at boot time?

Suppose there is a relation r(a, b, c) with a b+-tree index with search keys (a, b).1. what is the worst-case cost of finding records satisfying 10 < a < 50 using this index, in terms of the number of records n1, retrieved and the height h of the tree? 2. what is the worst-case cost of finding records satisfying 10 < a < 50 and 5 < b < 10 using this index, in terms of the number of records n2 that satisfy this selection, as well as n1 and h defined above? 3. under what conditions on n1 and n2, would the index be an efficient way of finding records satisfying the condition from part (2)?