cs186_sp08_mt2 9

cs186_sp08_mt2 9 - The most frequent operations against...

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d. Consider the following relation instance: Character Job Dating Gender HairColor Jim Salesman Pam Male Brown Pam Receptionist Jim Female Sandy blonde Michael Manager Jan Female Blonde Stanley Salesman Nobody Male Black d.1 What functional dependencies exist for this relation? What are the candidate keys of the relation? 4. Physical design (7 points) Consider the following relation schema: UserProfiles(UserId, PasswordHash, RealName, ZipCode, Preferences, Avatar, LoginStatus) – PrimaryKey(UserID) Friends(UserId1, UserId2) Posts(UserId, Topic, Subject, Text, Date)
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Unformatted text preview: The most frequent operations against this database are: i. Users log in, requiring a lookup of UserProfiles, at a rate of 1,000 per second ii. Users check to see the LoginStatus of their friends, requiring a join of Friends and UserProfiles, at a rate of 10,000 per second iii. New users are added to UserProfiles, at a rate of 1 per second iv. Users enter new posts, inserting tuples into Posts, at a rate of 100 per second v. Users view the subjects of the posts for a topic on a given day, at the rate of 1,000 per second...
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