DBMS-Transaction Processing and Concurrency Control
DBMS-Transaction Processing and Concurrency Control
61. In which of the following schedule are the transactions performed one after another, one at a time ?
- Non-serial schedul
- Conflict serialisable schedule
- Serial schedule
- None of these
62. A shared lock exists when concurrent transations are granted the following access on the basis of a common lock ;
- READ
- WRITE
- SHRINK
- UPDATE
63. In growing phase, a transaction acquires all the required locks
- by locking data
- without unlocking any data
- with unlocking any data
- None of these
64. Which of the following is an optimistic concurrency control method ?
- Validation-based
- Timestamp ordering
- Lock-based
- None of these
65. The basic variants of timestamp-based methods of concurrency control are
- Total timestamp ordering
- Partial timestamp ordering
- Multiversion timestamp ordering
- All of these
66. In optimistic methods, each transaction moves through the following phases:
- read phase
- validation phase
- write phase
- All of these