DB Recovery Systems Mcqs
Our collections of Multiple choice questions and answers focuses on study of ” DB Recovery Systems “. These questions are chosen from a collection of most authoritative and best reference books on DBMS. Our aim is to prepare an individual for competitive exams like NTS | GAT | ECAT | Data Warehouse jobs | Data Mining | DB administration jobs | Nadra Jobs | Software House and Data Base and Web Developer jobs | University and College entrance exams and various tests and job interviews. One should practice our Mcqs to assimilate knowledge on DB Recovery Systems comprehensively.
32. A __________ checkpoint is a checkpoint where transactions are allowed to perform updates even while buffer blocks are being written out.
Temporary
Fuzzy
Permanent
Recovery
33. If the database modifications occur while the transaction is still active, the transaction is said to use the __________ modification technique
Deferred
Immediate
More than one of the mentioned
None of the mentioned
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34. The log is a sequence of _________ recording all the update activities in the database.
Log records
Records
Entries
Redo
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35. The current copy of the database is identified by a pointer, called ____________ which is stored on disk.
Db-pointer
Update log
Update log records
All of the mentioned
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36. A special redo-only log record is written to the log, where V1 is the value being restored to data item Xj during the rollback. These log records are sometimes called
Log records
Records
Compensation log records
Compensation redo records
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37. In order to reduce the overhead in retrieving the records from the storage space we use
Logs
Log buffer
Medieval space
Lower records
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38. The order of log records in the stable storage ____________ as the order in which they were written to the log buffer.
Must be exactly the same
Can be different
Is opposite
Can be partially same
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39. Before a block of data in main memory can be output to the database, all log records pertaining to data in that block must have been output to stable storage. This is
Read-write logging
Read-ahead logging
Write-ahead logging
None of the mentioned
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40. Writing the buffered log to __________ is sometimes referred to as a log force.
Memory
Backup
Redo memory
Disk
41. The _______________ policy, allows a transaction to commit even if it has modified some blocks that have not yet been written back to disk.
Force
No-force
Steal
No-steal
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42. ______________ policy allows multiple updates to accumulate on a block before it is output to stable storage, which can reduce the number of output operations greatly for frequently updated blocks.
Force
No-force
Steal
No-steal
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43. The ___________ policy, allows the system to write modified blocks to disk even if the transactions thatmade those modifications have not all committed.
Force
No-force
Steal
No-steal
44. Locks on buffer blocks are unrelated to locks used for concurrency-control of transactions, and releasing them in a non-two-phase manner does not have any implications on transaction serializability. This is
Latches
Swap Space
Dirty Block
None of the mentioned
45. The __________________ contains a list of blocks that have been updated in the database buffer.
Latches
Swap Space
Dirty Block
None of the mentioned
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