Computer Knowledge

Database Management Systems

5,344 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.

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Database Management Systems Questions

Multiple choice technology security

Database views provide which type of security control?

  1. Detective

  2. Corrective

  3. Preventive

  4. Administrative
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Database views are preventive controls because they restrict user access to specific rows, columns, or subsets of data. By limiting what data users can see or query, views prevent unauthorized access to sensitive information. They don't detect violations (detective) or correct issues (corrective) - they proactively restrict access.

Multiple choice technology databases

What is the impact if DSS database goes down

  1. Authorization impacted

  2. Authentication impacted

  3. Billing period data unavailable

  4. alert info unavailable
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The DSS (likely Directory Security Service or similar) handles authentication - verifying user identity. If it goes down, users cannot log in or authenticate, though authorized users' existing sessions may continue to function temporarily. Authorization (permissions) and billing data are handled by separate services.

Multiple choice

Which of the following objects acts as a mediator between the DataSet object and the database?

  1. DataAdapter Object

  2. DataReader Object

  3. DbConnection

  4. DbCommand

  5. DataTable
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The DataAdapter object acts as a mediator between the DataSet object and the database. This helps the data set to contain data from more than one databases or other data source. It must be provided with a set of data commands and a database connection used to fill the DataSet and update a database.

Multiple choice

Consider three data items D1, D2 and D3, and the following execution schedule of transactions T1, T2 and T3. In the diagram, R(D) and W(D) denote the actions reading and writing in the data item D respectively.

Which of the following statements is correct?

  1. The schedule is serialisable as T2; T3; T1.

  2. The schedule is serialisable as T2; T1; T3.

  3. The schedule is serialisable as T3; T2; T1.

  4. The schedule is not serialisable.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Multiple choice

Which of the following scenarios may leave the transaction vulnerable to dirty reads, phantom reads, etc. in a database system?

  1. A transaction writes a data item after it is read by an uncommitted transaction.

  2. A transaction reads a data item after it is read by an uncommitted transaction.

  3. A transaction reads a data item after it is written by a committed transaction.

  4. A transaction reads a data item after it is written by an uncommitted transaction.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

 This may leave the transactions vulnerable to dirty reads, phantom reads, etc. in the database system.

Multiple choice

Consider the following log sequence of two transactions on a bank account, with initial balance of Rs. 12,000, that transfers 2000 to a mortgage payment and then applies a 5% interest.

  1. T1 start
  2. T1 B old = 1200 new = 10000
  3. T1 M old = 0 new = 2000
  4. T1 commit
  5. T2 start
  6. T2 B old = 10000 new = 10500
  7. T2 commit

Suppose the database system crashes just before log record 7 is written. When the system is restarted, which statement is true for the recovery procedure?

  1. We must redo log record 6 to set B to 10500.

  2. We must undo log record 6 to set B to 10000 and then redo log records 2 and 3.

  3. We need not redo log records 2 and 3 because transaction T1 has committed.

  4. We can apply redo and undo operations in arbitrary order because they are idempotent.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Multiple choice

Access is a/an

  1. RDBMS (Relational DBMS)

  2. DDBMS (Distributed DBMS)

  3. Server

  4. Protocol

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Microsoft Access is a Relational Database Management System (RDBMS) that stores data in related tables using keys and relationships. It is not a Distributed DBMS (DDBMS), a server, or a protocol - it's desktop database software using the relational model.

Multiple choice

How many types of relationships are there in MS-Access?

  1. 3

  2. 4

  3. 5

  4. 6

  5. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

MS Access supports 3 types of table relationships: One-to-One, One-to-Many, and Many-to-Many. These are the fundamental relationship types in relational database design and Access specifically supports these three.

Multiple choice

Datatype is

  1. a field that determines what kind of data it can hold

  2. a large number

  3. a constant that determines what kind of data it can hold

  4. none of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A datatype defines what kind of values a variable, field, or expression can hold (like integers, text, dates, etc.). It determines the memory allocation and valid operations. Option A correctly describes this fundamental concept - datatypes specify data constraints and capabilities, not numerical values or constants.

Multiple choice

An user interacts with

  1. database

  2. information

  3. visual basic front end

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Users interact with the Visual Basic front end, which consists of forms and controls (buttons, text boxes, etc.) that make up the user interface. This front end is what users see and click on, while the database and information handling happen behind the scenes.