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.

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Database Management Systems Questions

Multiple choice

SQLite is ________ type of database.

  1. network

  2. object–oriented

  3. relational

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

SQLite is a relational database engine. It uses SQL (Structured Query Language) for queries, supports tables with defined schemas, relationships between tables through foreign keys, and standard relational database concepts like indexes and views. It is not a network or object-oriented database.

Multiple choice

SQLite database needs _________ connection.

  1. JDBC

  2. ODBC

  3. network

  4. no

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

SQLite in Android does NOT use JDBC, ODBC, or any network connection. Android provides its own SQLite API through SQLiteDatabase and SQLiteOpenHelper classes that directly interact with the database file. This is different from how you'd access SQLite in a Java desktop application using JDBC.

Multiple choice

SQLite is written or developed using

  1. Android

  2. Java

  3. ANSI-C

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

SQLite is a C-language library, written in ANSI-C for maximum portability across platforms. While Android uses SQLite extensively, SQLite itself was not written in Android or Java - it's a standalone C library that Android incorporates.

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

Which name is suitable to run a macro at starting time to database?

  1. Start.exe

  2. Auto.exe

  3. Macro.exe

  4. Any of the above

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

In MS Access, macros are named .macro (not .exe files), and the special AutoExec macro runs automatically when the database opens. None of the listed .exe filenames (Start.exe, Auto.exe, Macro.exe) are used for this purpose - the correct approach is creating a macro named AutoExec.

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

_________ is the process of summarising data from more than one source.

  1. Data validation

  2. Data consolidation

  3. Data form

  4. Data filter

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

Data consolidation is the process of combining, summarizing, or aggregating data from multiple sources or ranges into a single summary. Data validation ensures data integrity, data form is for entry, and data filter shows/hides records.

Multiple choice

Which of the following is a DBMS software?

  1. Access

  2. Excel

  3. Word

  4. Power point
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Microsoft Access is a database management system (DBMS) that stores data in its own format based on the Access Jet Database Engine. Excel is a spreadsheet application, Word is a word processor, and PowerPoint is a presentation software - none of these are database management systems.

Multiple choice

How many types of database objects are there in MS-Access?

  1. 5

  2. 6

  3. 7

  4. 8

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

MS Access has seven main types of database objects: Tables, Queries, Forms, Reports, Macros, Modules, and Pages (for data access pages). These objects work together to create a complete database application.

Multiple choice

Unlike filters, queries can be saved as _______ in a database.

  1. objects

  2. filters

  3. database

  4. files

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

Queries are saved as database objects in Access, similar to tables, forms, and reports. Unlike filters which are temporary view settings, queries are reusable objects stored in the database. Filters cannot be saved as standalone objects.