Asingle-user database system automatically ensures of the database, because only one transaction is executed at a time. serializability and durability serializability and isolation atomicity and serializability atomicity and isolation

1.the index finger on your right hand types the f r v 4 j u m 7 h y 6 n lo.9 j u 7 m g t 5 b 2.if you need to multiply 400, 2, and 1 ½, what would you type on the numeric keypad? 400*2*1.5 400/2*1.5 400/2/1.5 400*2*1½ 3.select all examples of proper keyboarding technique. rest your fingers gently on the home row or home keys. slouch in your chair. rest your palms on the keyboard. relax your fingers. keep your hands lower than your elbows.

Jennifer has to set up a network in a factory with an environment that has a lot of electrical interference. which cable would she prefer to use? jennifer would prefer to use because its metal sheath reduces interference.

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)?