CS 6360 Final Exam Extra Practice Exercises Chapter 19 Query Optimization Consider the following join DEPARTMENT Dnumber Dnum PROJECT Using attribute values from Figure 19 8 in your textbook for reference calculate the values of the following attributes DEPARTMENT table Number of rows rD Number of blocks bD Blocking factor bfrD PROJECT table Number of rows rP Number of blocks bP Blocking factor bfrP DEPARTMENT Dnumber Dnum PROJECT Blocking factor of resulting join bfrDP Selectivity of join sl Selection Cardinality of join s Compare the cost difference between both DEPARTMENT as outer loop and PROJECT as outer loop and determine the more optimal cost of the two Hint Use variations of J2 for both directions Chapter 21 Transaction Processing 21 22 Which of the following schedules is conflict serializable For each serializable schedule determine the equivalent serial schedules a r1 X r3 X w1 X r2 X w3 X b r1 X r3 X w3 X w1 X r2 X c r3 X r2 X w3 X r1 X w1 X d r3 X r2 X r1 X w3 X w1 X 21 23 Consider the three transactions T1 T2 and T3 and the schedules S1 and S2 given below Draw the serializability precedence graphs for S1 and S2 and state whether each schedule is serializable or not If a schedule is serializable write down ALL of the equivalent serial schedule s If a schedule is non serializable write down ALL of the cycles T1 r1 X r1 Z w1 X T2 r2 Z r2 Y w2 Z w2 Y T3 r3 X r3 Y w3 Y S1 r1 X r2 Z r1 Z r3 X r3 Y w1 X w3 Y r2 Y w2 Z w2 Y S2 r1 X r2 Z r3 X r1 Z r2 Y r3 Y w1 X w2 Z w3 Y w2 Y
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