Database Management System MCQs

____________ using a log record sets the data item specified in the log record to the old value.

In the __________ phase, the system replays updates of all transactions by scanning the log forward from the last checkpoint.

The actions which are played in the order while recording it is called ______________ history.

A special redo-only log record < Ti, Xj, V1> 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

In order to reduce the overhead in retrieving the records from the storage space we use

The order of log records in the stable storage ____________ as the order in which they were written to the log buffer.

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

Writing the buffered log to __________ is sometimes referred to as a log force.

The _______________ policy, allows a transaction to commit even if it has modified some blocks that have not yet been written back to disk.

______________ 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.

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

The __________________ contains a list of blocks that have been updated in the database buffer.

The operating system reserves space on disk for storing virtual-memory pages that are not currently in main memory; this space is called

The silicon chips used for data processing are called

Which of the following is used for manufacturing chips?

What was the name of the first commercially available microprocessor chip?

The magnetic storage chip used to provide non-volatile direct access storage of data and that have no moving parts are known as

The ALU of a computer normally contains a number of high speed storage element called

Which of the following is used only for data entry and storage, and never for processing?

A dump of the database contents is also referred to as an _____________ dump.

________ dump, writes out SQL DDL statements and SQL insert statements to a file, which can then be reexecuted to re-create the database.

_________ dump schemes have been developed that allow transactions to be active while the dump is in progress.

ARIES uses a ___________ to identify log records, and stores it in database pages.

ARIES supports ___________ operations, which are physical in that the affected page is physically identified, but can be logical within the page.

______________ is used to minimize unnecessary redos during recovery.

__________ scheme that records only information about dirty pages and associated information and does not even require of writing dirty pages to disk.

Whenever an update operation occurs on a page, the operation stores the LSN of its log record in the _______ field of the page.

There are special redo-only log records generated during transaction rollback, called _________ in ARIES.

___________ determines which transactions to undo, which pages were dirty at the time of the crash, and the LSN from which the redo pass should start.

__________ starts from a position determined during analysis, and performs a redo, repeating history, to bring the database to a state it was in before the crash.

______________ rolls back all transactions that were incomplete at the time of crash.

Which lock should be obtained to prevent a concurrent transaction from executing a conflicting read, insert or delete operation on the same key value.

Once the lower-level lock is released, the operation cannot be undone by using the old values of updated data items, and must instead be undone by executing a compensating operation; such an operation is called

Which of the following is used for undo operations alone?

Redo operations are performed exclusively using

To perform logical redo or undo, the database state on disk must be operation ___________ that is, it should not have partial effects of any operation.

Immediate database modification technique uses

Shadow paging has

For correct behaviour during recovery, undo and redo operation must be

If ___________ are not obtained in undo operation it will cause problem in undo-phase.

The remote backup site is sometimes also called the

Remote backup system must be _________ with the primary site.

The backup is taken by

When the __________ the backup site takes over processing and becomes the primary.

The simplest way of transferring control is for the old primary to receive __________ from the old backup site.

The time to process the remote backup can be reduced by

A transaction commits as soon as its commit log record is written to stable storage at the primary site. This is

A transaction commits as soon as its commit log record is written to stable storage at the primary and the backup site. This is

If only the primary is active, the transaction is allowed to commit as soon as its commit log record is written to stable storage at the primary site. This is