Test ing of multiple database based advanced Please answer all the questions, I'm on the exam now The answer is accurate, please. Thank you, mr.

. Q1 The following Schedule: [5 r1(x); w1(x), 12(2), (2), 13(x), 13(Y); C1; W3 (Y); C3; r2 (V); W2 (Z), W2 (Y), c2]is best described as. A. Caseadeless B. Recoverable C. None of them D. Strict Q2 Based on recoverability of schedules, which is true? A. A cascadeless schedule is strict. B. A recoverable schedule is strict. C. A strict schedule is cascadeless. D. A recoverable schedule is cascadeless. Q3 A transaction enters the "partially committed" state when : a. An error occurred. b. Writing data items to disk. C. Writing buffer pages to disk. d, Writing log records to disk Q4 Partially-committed transaction cannot be rolled-back: a. TRUE b. FALSE Q5 strict schedule guarantees not having a Dinty read problem. :a. FALSE . b. TRUE Q6 Database transaction has to be executed in all or none, this , property is called: a. Isolation b. Atomicity C. Durability . d. Consistency Q7 A schedule Si is conflict schedule if : A. $1 is conflict equivalent to any schedule s2 B. None of them C. $1 is CONFLICT equivalent to any serial Schedule s2 D. S1 is not equivalent to any serial schedule s2 Q8 A transaction could be aborted (before it commits) because: a. Local transaction error. b. Serializability violation C. All d. Deadlock detection 09 There is a possibility of a cascading rollback when a transaction: a. both (b) and (c). b. (c) reads an item that is previously wrtten by an uncommitted transaction. C. (a) writes items that have been written only by a committed transaction. d. (b) writes an item that is previously written by an uncommitted Q10 Cascadeless schedule aranicesnctiaving a lost update problem". a FALSE B. TRUE Q11 Which statement of the following is correct? a. Each cascade less schedule is strict. b. Each recoverable schedule is strict .c. Each strict schedule is cascade less. d. Each recoverable schedule is cascade less. Q12 A schedule S1 is conflict equivalent to a schedule S2 if: a. (a) and (b) must be satisfied b. (b) All of the conflicted operations in S1 are also in S2 in the same order C. None of them d. (a) All operations of all transactions in S1 are also in S2 Q13 To overcome Catastrophic (disk) failures, it is necessary for the DBMS: a. all of the above. b. to keep a backup copy of the database. C. to never abort a transaction. d. to only execute transactions in a single user environment. Q14 Lost update problem is a description of write operation on a data item X, such that: Select one: a. A transaction read X and another transaction wrote X next. b. A transaction wrote x and anther transaction wrote X next. C. A transaction read X and another transaction read X next. D. A transaction wrote X and another transection read X next. Q15 System log is used to recover a database to its latest consistent state. a. FALSE b. TRUE Q16 The size of a data item is called its granularity, and it could be a field of some record. a. FALSE b. TRUE Q17 R1(x) and W2(V) are conflicting operations. Select one: a. FALSE b. TRUE