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 technology databases

what is the view that provides the job history ?

  1. all_scheduler_job_log_

  2. dba_scheduler_job_logs

  3. users_scheduler_job_log

  4. all the above

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

Oracle's Scheduler job run history is stored in *_SCHEDULER_JOB_RUN_DETAILS, while the logs are in *_SCHEDULER_JOB_LOG. The listed options are incorrectly spelled or missing the standard Oracle views, making 'None' the correct choice.

Multiple choice technology databases

Which package in plsql provides scheduling ?

  1. DBMS_SCHEDULER package

  2. DBMS_SCHEDULE package

  3. DBMS_JOB package

  4. Both A & C

  5. None
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In Oracle PL/SQL, scheduling is provided by both the older DBMS_JOB package and the newer, more advanced DBMS_SCHEDULER package. Therefore, the option representing both A (DBMS_SCHEDULER) and C (DBMS_JOB) is correct.

Multiple choice technology

5) workflow structure in LR is i) s_Load _source_data ii) decision iii) s_Create_account_table iv) worklets of various products

  1. i,ii,iii ,iv

  2. ii,i,iii ,iv

  3. i,iii,ii ,iv

  4. iii,i,ii ,iv
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The correct workflow in LoadRunner is: first load source data (s_Load_source_data), then create the account table structure (s_Create_account_table), then make decisions about data allocation (decision), and finally execute worklets for various products. This sequence ensures data is loaded before structure is created, and decisions happen after structure is established.

Multiple choice technology web technology

What is Workflow?

  1. Property of sitecollection

  2. Ability to perform a pre-defined process for a list or library item

  3. Import data from database

  4. All of the above

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

Workflow in SharePoint is the ability to automate and execute predefined business processes on list or library items (e.g., approval processes, document review). It's not a property, nor is it about importing data. Option E is incorrect since B is the valid answer.

Multiple choice technology databases

What was a problem with navigational data access languages?

  1. The user had to have knowledge of the table and index structures

  2. Navigational data access was far slower than declarative access

  3. Navigational access languages required the coder to embed their queries inside a procedural language shell

  4. Navigational languages were far slower then SQL
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Navigational data access languages (like CODASYL) required users to understand the physical database structure including table relationships, pointer chains, and index structures. This made them more complex to use compared to declarative languages like SQL where the database optimizer handles navigation.

Multiple choice technology databases

Which of the following is an important feature of relational databases and SQL

  1. Independence of table relationships

  2. High speed of SQL

  3. Powerful GUI front-end

  4. Easy to install and use
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A fundamental design goal of relational databases is data independence, allowing table structures and relationships to be logical rather than physical. Other choices like SQL speed, GUI availability, or ease of installation are non-fundamental characteristics of relational theory.

Multiple choice technology databases

Which of the following is an important consideration when tuning an SQL statement

  1. The number of CPUs on the server

  2. The degree of parallelism on the tables

  3. The use of bitmap indexes

  4. The quality of the SQL optimization
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The quality of the SQL optimizer is critical because it chooses the access paths and execution plans. While hardware factors (like CPUs) and physical schema choices (parallelism, indexes) matter, the optimizer's decisions directly determine the runtime efficiency of the query.

Multiple choice technology databases

Which of the following database design features is most important to SQL performance?

  1. Removal of data redundancy

  2. The introduction of data redundancy

  3. The introduction of non-first normal form relations

  4. The introduction of SQL*Plus
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Strategic introduction of controlled data redundancy (denormalization) improves SQL performance by reducing expensive joins and table scans. While normalization removes redundancy for data integrity, controlled denormalization is a key performance optimization technique.

Multiple choice technology databases

While attempting to connect to a database stored on an iSeries server from a Windows client, the following message was displayed: SQL1013N The database alias name or database name "TEST_DB" could not be found. Which of the following actions can be used to help determine why this message was displayed?

  1. Execute the LIST REMOTE DATABASES command on the server; look for an entry for the TEST_DB database

  2. . Execute the LIST DCS DIRECTORY command on the server; look for an entry for the TEST_DB database

  3. Execute the LIST REMOTE DATABASES command on the client; look for an entry for the TEST_DB database

  4. Execute the LIST DCS DIRECTORY command on the client; look for an entry for the TEST_DB database
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The DB2 error SQL1013N on a client machine means the local client catalogs cannot locate the database alias. Executing LIST DCS DIRECTORY on the client verifies whether the Database Connection Services directory contains the appropriate database mapping.

Multiple choice technology databases

Which of the following commands is used to retrieve database names from the local catalog for DRDA host databases on System i and System z?

  1. LIST DB DIRECTORY

  2. LIST DCS DIRECTORY

  3. LIST NODE DIRECTORY

  4. LIST ACTIVE DATABASES
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

LIST DCS DIRECTORY is used to retrieve database names from the local catalog for DRDA (Distributed Relational Database Architecture) host databases on System i and System z platforms. DCS (Database Connection Services) directory maintains information about DRDA host databases. LIST DB DIRECTORY lists local databases, LIST NODE DIRECTORY lists node directory entries, and LIST ACTIVE DATABASES shows currently active databases.

Multiple choice technology databases

What is the maximum size that can be specified when creating an XML column in a DB2 table?

  1. No size is specified

  2. The buffer pool size

  3. The page size for the table space

  4. The extent size for the table space
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When creating an XML column in DB2, no size specification is required or allowed. XML data is stored internally in a parsed hierarchical format, and DB2 manages the storage automatically. The buffer pool size, page size, and extent size are table space storage attributes, not column-level specifications for XML data.

Multiple choice technology databases

Within the application MY_APP the following PREVIOUS VALUE expression references the sequence MY_SEQ: PREVIOUS VALUE FOR my_seq After which of the following events will the most recently generated value of MY_SEQ persist so that it can be returned to the active MY_APP application?

  1. After a ROLLBACK is issued

  2. .After the sequence is altered

  3. After the sequence is dropped

  4. After the current session ends
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The PREVIOUS VALUE for a sequence is session-specific and persists within the active application session even after a transaction ROLLBACK. Altering or dropping the sequence deletes its definition or state, and ending the current session destroys the session-bound context where the previous value is tracked.

Multiple choice technology databases

Which of the following describes the objects of a DB2 database and their relationships?

  1. Instance

  2. Table space

  3. System catalog

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

To solve this question, the user needs to know about the components of a DB2 database and their functions.

A. Instance: This refers to the environment in which DB2 runs. An instance includes system memory, a set of processes, and a set of configuration files. It is responsible for managing the overall operation of the database.

B. Table space: This is where the actual data is stored in a DB2 database. A table space consists of one or more containers that hold the actual data. Each container can be a file or a set of files.

C. System catalog: This is a set of tables that hold metadata about the database objects, such as tables, indexes, views, etc. It is used by DB2 to manage the database and its objects.

D. Schema repository: This is a collection of schemas, which are logical containers for database objects such as tables, views, indexes, etc.

Among the given options, C is the correct answer as the system catalog is responsible for storing metadata about the database objects and their relationships. It provides information about tables, indexes, views, permissions, etc. and is used by the DB2 system to manage the database and its objects. Therefore, the correct answer is:

The Answer is: C