Recitation #3

*** Still not finished (but you can at least start...) *** Paper Problems 1. r_1(x), r_2(x), w_1(x),w_2(x)

Write the DSG for the above schedule.Is this schedule conflict serializable? Is this schedule view serializable?

2. w_2(z),r_1(x),r_1(y),r_2(y),w_1(x),r_2(x),w_2(y),w_1(z),w_2(z)

Is this schedule conflict serializable? Is this schedule view serializable?

3. Assume that the following schedule with locks is executed over a SVCC mechanism.

rlk_1(x), r_1(x), rlk_2(x), wlk_1(x),w_1(x),ulk_1(x),cmt_1, wlk_2(x),w_2(x),ulk_2(x), cmt_2

Describe what happens.Does this schedule respect 2PL, SS2PL (AKA ‘Rigorous’), Conservative 2PL?

¶ To be continued... ¶ System Exercises ¶4. Which SQL isolation levels are met with schedules that observe: a. locking protocols b. 2PL c. SS2PL (AKA 'Rigorous') d. Conservative and Rigorous¶

System Exercises Consider we have 2 runways and three time slots that planes may land. We represent this scenario in the following table: ¶

runway time_slot flight condition 1 1 NULL fair 1 2 NULL fair 1 3 NULL fair 2 1 NULL fair 2 2 NULL fair 2 3 NULL fair