Question

For each of the following statements, circle T (True) or F (False) Serial execution of a set of transactions is guaranteed to preserve database consistency. When using the two-phase locking protocol, two transactions can hold shared locks on the same data element at the same time. The recovery manager ensures the Atomicity property of a transaction by committing all operations of aborted transactions. A B+ tree index, that starts a root node, is rarely used in a relational database. Deadlocks can never happen when using the two-phase locking protocol is used. A transactions can exist in five different states (active, committed, failed, aborted or partially committed). A index might help speed up the performance of a query, by reducing the amount of 1/0 a DBMS has to perform. 8 The crash recovery algorithm consists of two phases, the first is the Redo phase and the second is the Undo phase. The best way and performance for a DBMS engine to guarantee data consistency is to run all transaction in a serial schedule. Page TF Triggers can only be activated before an update/insert/delete into a relation, but not after.

Answer 1

False I serial execution of a set of transaction is gusateed to preserve database consistory True False Reason: It preserve database consistency. 2. when using two-phase locking protocol, twis transaction can hold shared locks on the same data element at the same. True False. Reason: It allorus & only read-only mode. 3. The recovery manager ensure the Atomicity property of a transaction by committing all operation of aborted transotich. TRUE I False 14. A Bt free index, that starts a noet node, is rarely used in relational database. TRUE FALSET Reason: Bt tree index and Hoshing are used frequently 5. using is wed Deadlocks com never happen when the two- phase locking protoed TRUE FALSET Reason: There are possibilition for in two-phose locking dood lock

6.) A transaction can exist in five differed stales (active commited, fribed aborted, partially committe) TRUE FALSE up the the performance amount of 7. A indesc might help speed of a Query by reducing Ilo a Doms has to perform TRUE FALSE. 8. A (rosh recovery algorithm phase, the first ý the the second is the undo consist of Redo phase phare. two and TRUE FALSE TRUE 9. The best way and performance for a DBMS engine to guarantee data consistency is to sam all transaction in a serial Schedule TRUE FALSE Reason: If two transaction works on same data then this schedule makes DB to inconsistent 10. Triggers con only be octivated before an update / insest I delete into a relation but not ofter. TRUE FALSE Reason Tricgger con be activated also ofter the update / insert I delete overation