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

In which of the following memory components of the SGA are the sizes of the two caches, such as library cache and the data dicitionary caches not set individually and are automatically determined by the Oracle server?

  1. The stream pool

  2. The shared pool

  3. The java pool

  4. Session memory

  5. The password file
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In this memory component of the SGA, the sizes of the library cache and the data dictionary caches are not set  individually and are automatically determined by the Oracle server.

Multiple choice

Which of the following is the correct statement about the System Global Area (SGA) in memory structure of Oracle Database?

  1. It is a shared memory region that contains data and control information for one Oracle instance.

  2. The database buffers and the shared pool are not the parts of SGA.

  3. It also consists of stack-space and session-information.

  4. It maintains the memory in a non-shared medium.

  5. One can create a number of instances for the shared memory.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Oracle allocates the SGA when an instance starts and deallocates it when the instance shuts down.

Multiple choice

Which of the following is correct about the Archive log files in Oracle database?

  1. These files are used to copy the redo log file in a single location.

  2. These files are mandatory to apply changes to a standby database.

  3. These files are used exclusively for temporary storage data.

  4. These files provide the physical storage of data, which can consist of the data-dictionary data.

  5. It provides data specific usability in the system.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is correct as these files perform recovery after a media failure and archive to multiple locations for the specific database.

Multiple choice

Which of the following is an incorrect statement about Control files in Oracle database?

  1. These files provide the physical storage of data, which consists of the data-dictionary data.

  2. These files have the information about the physical structure of a database.

  3. These files have the information about the time stamp of the database creation, the current log sequence number and the checkpoint information.

  4. At the physical level, data files comprise one or more data blocks.

  5. These files maintain the information of the database.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Data and index files provide such information. Control file does not provide physical storage of data but have information about the physical structure of the database.

Multiple choice

Which of the following is correct about 'Library cache' in Oracle database?

  1. It is responsible for storing the shared SQL statements and execution steps for that.

  2. It is used to enhance the amount of memory needed and the processing-time used for parsing and execution planning.

  3. It has user information and user privileges.

  4. In this cache, the information on space is allocated and used for schema objects.

  5. In this cache, the information is managed as per the specific execution plan.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The library cache stores shared SQL, caching the parse tree and the execution plan for every unique SQL statement.

Multiple choice

Which of the following information does the data dictionary cache not contain in Oracle database?

  1. It has user information, such as user privileges.

  2. It contains the names and datatypes of all columns in database tables.

  3. It has integrity constraints defined for tables in the database.

  4. It has names and datatypes of all columns in database tables.

  5. It is not suitable for user authentication.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

It provides user authentication effectively.

Multiple choice

What is 'stack-space' in Program Global Area?

  1. It is the memory that holds the session's variables, arrays and so on.

  2. In this, the database instance stores its session-information in the PGA and the session-information goes in the SGA.

  3. It is an area that holds information such as bind-variables and runtime-buffers.

  4. It is an area in the PGA that holds information on sorts, hash-joins etc.

  5. It is the area that stores the information about memory management.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This is correct about 'stack-space' in Program Global Area. It stores all these information in its memory area.

Multiple choice

What is 'private SQL-area' in Program Global Area in Oracle database?

  1. It is the memory that holds the session's variables, arrays and so on.

  2. In this, the database instance stores its session-information in the PGA and the session-information goes in the SGA.

  3. It is an area that holds information such as bind-variables and runtime-buffers.

  4. It is an area in the PGA that holds information on sorts, hash-joins etc.

  5. It has the information about memory utilization.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is called 'private SQL-area'. It has all the runtime-buffer related information for every database.

Multiple choice

Which of the following is incorrect about 'Shared Pool' in SGA?

  1. It stores the program code.

  2. It has information about a connected session, even if it is not currently active.

  3. It has the information needed during program execution.

  4. It has the information about the cached data that is also permanently stored on peripheral memory.

  5. It does not have the information related to cache and memory.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is incorrect as Shared pool is responsible for all such information.

Multiple choice

Which of the following is false statement about Automatic Locking in Oracle database?

  1. Oracle locking is performed automatically and requires no user action.

  2. Oracle's lock manager automatically locks table data at the row level.

  3. Oracle's lock manager maintains several different types of row locks.

  4. There are two general types of locks-exclusive locks and share locks.

  5. Exclusive lock checks the status of memory leak.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Executive lock does not check the status of memory leak.