Computer Knowledge

Database Management Systems

5,543 Questions

Database Management Systems (DBMS) form the core framework for data storage, retrieval, and security in modern software applications. Concepts such as the E-R model, backup planning, SQL integration, and big data architecture are essential for computer knowledge sections. This hub offers a comprehensive set of practice questions to master DBMS fundamentals and advanced database operations.

E-R Model ConceptsBackup and RecoverySQL Server UpgradesJDBC and ODBCBig Data CharacteristicsData VirtualizationOracle Database

Database Management Systems Questions

Multiple choice

Which one of the following failures in a database may decide to abort the transaction to be restarted later because it violates serialisability or because several transactions are in a state of deadlock?

  1. Computer failure

  2. A transaction or system error

  3. Local errors

  4. Concurrency control

  5. Disk failure
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This failure in the database may decide to abort the transaction to be restarted later because it violates serialisability or because several transactions are in a state of deadlock.

Multiple choice

Which of the following is the simplest and also substantial means to improve performance of Oracle using partitioning?

  1. Partition-wise joins

  2. Partitioning pruning

  3. Global partitioned indexes

  4. Composite range hash partitioning

  5. Global non-partitioned indexes
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is the simplest and also the most substantial means to improve performance of Oracle using partitioning. It improves query performance by several orders of magnitude.

Multiple choice

Which of the following cost components for query execution is the cost of searching for reading and writing data blocks that reside on secondary storage mainly on disks?

  1. Storage cost

  2. Computation cost

  3. Memory usage cost

  4. Access cost to secondary storage

  5. Communication cost
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This cost component for query execution is the cost of searching for reading and writing data blocks that resides on secondary storage mainly on disks.

Multiple choice

Which of the following is/are used in Oracle to connect to non-Oracle data stores by using either a Heterogeneous Services ODBC agent or a Heterogeneous Services OLE DB agent?

  1. Transparent Gateway Agents

  2. Database link

  3. Generic connectivity

  4. Cursor

  5. Triggers
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This method is used in Oracle to connect to non-Oracle data stores by using either a heterogeneous services ODBC agent or heterogeneous services OLE DB agent.

Multiple choice

Which one of the following transactions is a transaction that includes one or more statements that, individually or in a group update, data on two or more distincts of a distributed database?

  1. Remote transaction

  2. Two-Phase commit mechanism

  3. Distributed transaction

  4. SNMP

  5. Enterprise manager
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This transaction is a transaction that includes one or more statements that, individually or in a group, update data on two or more distincts of a distributed database.