rollback requires the system to maintain additional information about the state of all the running transactions.

Related MCQs

• Which of the following is used to get back all the transactions back after rollback?
• Rollback of transactions is normally used to:
• 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 maintain the consistency during transactions, database provides
• A concurrency-control policy such as this one leads to              performance since it forces transactions to wait for preceding transactions to finish before they can start.
•                      are used to ensure that transactions access each data item in order of the transactions’          if their accesses conflict.
• Each of a pair of transactions has read data that is written by the other, but there is no data written by both transactions, is referred to as
• A system is in a              state if there exists a set of transactions such that every transaction in the set is waiting for another transaction in the set.
• In the                      phase, the system replays updates of all transactions by scanning the log forward from the last checkpoint.
• The                        policy, allows the system to write modified blocks to disk even if the transactions that made those modifications have not all committed.