MCQ IN COMPUTER SCIENCE & ENGINEERING

Detailed explanation-1: -A deadlock occurs when multiple users seeking access to the same set of records lockout each other. As a result, the transactions of all users assume a “wait” state until the locks are removed.

Detailed explanation-2: -In a database, a deadlock is a situation in which two or more transactions are waiting for one another to give up locks. For example, Transaction A might hold a lock on some rows in the Accounts table and needs to update some rows in the Orders table to finish.

Detailed explanation-3: -Optimistic locking allows multiple users to attempt to update the same record without informing the users that others are also attempting to update the record. The record changes are validated only when the record is committed.

Detailed explanation-4: -1. Shared Lock (S): Another transaction that tries to read the same data is permitted to read, but a transaction that tries to update the data will be prevented from doing so until the shared lock is released. Shared lock is also called read lock, used for reading data items only. Shared locks support read integrity.

Detailed explanation-5: -A deadlock is a condition where two or more transactions are waiting indefinitely for one another to give up locks. Deadlock is said to be one of the most feared complications in DBMS as no task ever gets finished and is in waiting state forever.