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

_________ maps to one or more columns in a database that are key to a query

  1. Dimension

  2. Detail

  3. Measaure

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

A Dimension maps to one or more descriptive columns in a database that are used for grouping, filtering, or labeling in queries. Dimensions provide context for measures (numerical values) in data warehousing and BI. Details and objects are not the correct terminology for column mappings.

Multiple choice technology databases

Where would you look for errors from the database engine?

  1. Database Log

  2. Alert Log

  3. Error Log

  4. Session Log
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The Alert Log is the correct location to look for errors from the Oracle database engine. It contains critical error messages, startup/shutdown information, and other important diagnostic events. Database logs, error logs, and session logs are not the standard Oracle terminology for engine-level error tracking.

Multiple choice technology databases

What are the min.extents allocated to a rollback extent?

  1. 1

  2. 2

  3. 3

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

A rollback segment in Oracle is allocated a minimum of 2 extents. This is the default behavior for rollback segment storage allocation. The other options (1, 3, 4 extents) are not the correct minimum extent allocation for rollback segments in standard Oracle configuration.

Multiple choice technology databases

When Database A has 5GB of spool space, Database B is created as child of Database A with 3GB of spool space, then Database A will have

  1. 2GB of spool space

  2. 5GB of spool space

  3. 2GB of permanent space

  4. 3GB of spool space
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In Teradata, spool space is not pre-allocated but is defined as an upper limit. Creating a child database with a portion of spool space does not reduce the spool space limit of the parent database; hence, Database A retains its 5GB limit.

Multiple choice technology databases

This temporary table will not be dropped once the session is signed off

  1. Volatile Temporary Table

  2. Global Temporary table

  3. MultiSet Table

  4. Permanent Table
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In Teradata, the definition of a Global Temporary Table (GTT) is persistent and remains in the data dictionary even after the session ends. In contrast, Volatile Temporary Tables (VTT) have their definitions and data completely dropped at session logoff.

Multiple choice technology databases

Volatile temporary table is materialized at

  1. Temporary Space

  2. Spool Space

  3. Permanent Space

  4. Any of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Volatile temporary tables are materialized in spool space, which is temporary workspace allocated during query execution. Spool space is specifically designed for intermediate results and transient data. Permanent space is for durable database objects, while temporary space is for other temporary storage needs.

Multiple choice technology databases

This temporary table will not be dropped once the session is signed off

  1. Volatile Temporary Table

  2. Global Temporary table

  3. MultiSet Table

  4. Permanent Table
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Global temporary tables persist beyond a single session - they survive sign-off but are eventually dropped by the system. Volatile tables are automatically dropped at session end. Multiset and permanent tables are completely different concepts with their own persistence rules.

Multiple choice technology databases

Volatile temporary table is materialized at

  1. Temporary Space

  2. Spool Space

  3. Permanent Space

  4. Any of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Volatile temporary tables are materialized in spool space, which is temporary workspace allocated during query execution. Spool space is specifically designed for intermediate results and transient data storage during query processing.

Multiple choice technology databases

When Database A has 5GB of spool space, Database B is created as child of Database A with 3GB of spool space, then Database A will have

  1. 2GB of spool space

  2. 5GB of spool space

  3. 2GB of permanent space

  4. 3GB of spool space
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In Teradata's hierarchical space management, when a child database is created with a spool allocation, it does not reduce the parent's spool space. The parent (Database A) retains its full 5GB spool allocation. The child's 3GB is a separate allocation, not a subtraction from the parent.

Multiple choice technology platforms and products

Identify the differences between an Infoset and a Multiprovider.

  1. Both Multiproviders and Infosets can contain all the info providers in BW.

  2. Queries built on Multiproviders use 'union' and queries on Infosets use 'join' to retrieve data from different info providers.

  3. Both Multiproviders and Infosets do not have data, but data is accessed from the basic info providers used in these objects.

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

Multiproviders and Infosets are both composite data providers in SAP BW that access data from underlying basic providers. The key difference is that Multiproviders use a union operation to combine data from multiple providers, while Infosets use join operations to link related data. Both objects do not store physical data themselves, instead accessing it in real-time from their constituent providers.

Multiple choice technology platforms and products

Select the correct statements about the OLAP Cache Monitor in BW.

  1. The transaction for the OLAP Cache Monitor is RSRCACHE.

  2. If the persistent mode is inactive then the cache is inactive and query results will not be cached in memory.

  3. A 'read flag' is set in the Cache Monitor when data is read from the cache.

  4. When new data is loaded into the info provider which the query is built on, the cache for that query is invalidated.

  5. All of the above.
Reveal answer Fill a bubble to check yourself
A,C,D Correct answer
Explanation

The OLAP Cache Monitor (transaction RSRCACHE) manages query result caching in BW. When persistent mode is inactive, cache can still operate in memory mode. A read flag is set when cached data is accessed. When new data is loaded into underlying info providers, related cache entries are invalidated to ensure query results remain current.

Multiple choice technology platforms and products

mws new -Dserver.name=test -Dhttp.port=8090 -Ddb.type=ms -Ddb.url=jdbc:wm:sqlserver:db_server:1433;DatabaseName=my_wm_msql;SelectMethod=direct;MaxPooledStatements=100 -Ddb.username=mws_user -Ddb.password=password

  1. This will connect the "test" MWS server to new database instance my_wm_msql

  2. Create the new instance of My webMethods Server "test"

  3. This will start the "test" MWS server to new port 8090 and connect to database instance my_wm_msql

  4. Create the new instance of My webMethods Server "test" and configure parameter as given in command line
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The mws new command creates a new My webMethods Server instance and configures it with all the specified parameters (server name, HTTP port, database type/URL/username/password) in one operation. Option D correctly describes this.

Multiple choice technology platforms and products

MWS Supports following external data sources

  1. Microsoft SQL Server

  2. Oracle

  3. DB2 Universal

  4. Sybase Adaptive Server

  5. Informix

  6. Generic ODBC, Custom JDBC
Reveal answer Fill a bubble to check yourself
A,B,C,D,E,F Correct answer
Explanation

MWS connects to diverse enterprise databases for data integration. The support ranges from proprietary systems like SQL Server and Oracle to universal connectivity through ODBC and JDBC, enabling flexible data source integration across different platforms.

Multiple choice technology platforms and products

Which statement(s) is/are true about Multiproviders?

  1. This is a virtual Infoprovider that does not store data

  2. They can contain InfoCubes, ODSs, info objects and info sets

  3. More than one info provider is required to build a Multiprovider

  4. It is similar to joining the data tables
Reveal answer Fill a bubble to check yourself
A,B Correct answer
Explanation

Multiproviders are virtual InfoProviders that combine data from multiple sources without storing it themselves (A is true). They can contain InfoCubes, ODS objects, InfoObjects, and InfoSets (B is true). However, single InfoProvider can build a Multiprovider (C is false), and they're not like table joins (D is false). Only A and B are correct.