Database Management System MCQs
749+ questions with answers
Which is refers to a stalemate situation due to which no further progress is possible as computer await response of each other:
Which is a duplicate copy of a file program that is stored on a different storage media than the original location:
Which is the duplication of computer operations and routine backups to combat any unforeseen problems:
Optimization that is basically related to the rewriter module is termed as__________
Optimization basically related to the Rewrite module is termed as_______
Database security helps organizations to protect data from _____
Which are types of recovery control techniques:
Which server can join the indexes when only multiple indexes combined can cover the query:
In concurrency control policy the lock is obtained on
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.
In which scenario would you use the ROLLUP operator for expression or columns within a GROUP BY clause?
Which statement is true regarding external tables?
A non-correlated subquery can be defined as ______
Evaluate the following SQL statements in the given order: DROP TABLE dept; CREATE TABLE dept (deptno NUMBER(3) PRIMARY KEY, deptname VARCHAR2(10)); DROP TABLE dept; FLASHBACK TABLE dept TO BEFORE DROP;
Which of the following is a property of transactions?
SNAPSHOT is used for (DBA)
Isolation of the transactions is ensured by
Constraint checking can be disabled in existing _______________ and _____________ constraints so that any data you modify or add to the table is not checked against the constraint.
Problems occurs if we don’t implement a proper locking strategy
Which of the following fixed database roles can add or remove user IDs?
Which of the following statements is/are not true for SQL profiler?
Which of the following is the original purpose of SQL?
SQL can be used to:
In order to maintain transactional integrity and database consistency, what technology does a DBMS deploy?
A lock that allows concurrent transactions to access different rows of the same table is known as a
Which of the following are introduced to reduce the overheads caused by the log-based recovery?
Which of the following protocols ensures conflict serializability and safety from deadlocks?
Which of the following is the block that is not permitted to be written back to the disk?
If transaction Ti gets an explicit lock on the file Fc in exclusive mode, then it has an __________ on all the records belonging to that file.
All lock information is managed by a __________ which is responsible for assigning and policing the locks used by the transactions.
The ____ lock allows concurrent transactions to access the same row as long as they require the use of different fields within that row.
Which of the following is a procedure for acquiring the necessary locks for a transaction where all necessary locks are acquired before any are released?
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.
The deadlock state can be changed back to stable state by using _____________ statement.
What are the ways of dealing with deadlock?
When transaction Ti requests a data item currently held by Tj, Ti is allowed to wait only if it has a timestamp smaller than that of Tj (that is, Ti is older than Tj). Otherwise, Ti is rolled back (dies). This is
When transaction Ti requests a data item currently held by Tj, Ti is allowed to wait only if it has a timestamp larger than that of Tj (that is, Ti is younger than Tj ). Otherwise, Tj is rolled back (Tj is wounded by Ti). This is
The situation where the lock waits only for a specified amount of time for another lock to be released is
A deadlock exists in the system if and only if the wait-for graph contains a ___________
Selecting the victim to be rollbacked to the previous state is determined by the minimum cost. The factors determining cost of rollback is
__________ rollback requires the system to maintain additional information about the state of all the running transactions.
In a granularity hierarchy the highest level represents the
In a database the file is contained in ________
If a node is locked in an intention mode, explicit locking is done at a lower level of the tree. This is called
If a node is locked in __________ explicit locking is being done at a lower level of the tree, but with only shared-mode locks.
If a node is locked in ____________ then explicit locking is being done at a lower level, with exclusive-mode or shared-mode locks.
If a node is locked in ______________ the subtree rooted by that node is locked explicitly in shared mode, and that explicit locking is being done at a lower level with exclusive-mode locks.
The _____________ ensures that any conflicting read and write operations are executed in timestamp order.