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
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You do not need to restore all the data files.
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You do not need to open the database with the RESETLOGS operation
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You do not need to perform a full backup after the RESETLOGS operation.
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You do not need to recover all the data files to the same system change number (SCN).
C
Correct answer
Explanation
This appears to be a duplicate of question 132806. In Oracle 10g, after incomplete recovery with RESETLOGS, the database is in a consistent state and doesn't require an immediate full backup (though it's recommended practice). Options A and D are incorrect - incomplete recovery still requires restoring all datafiles and recovering them to a consistent point. Option B is false - RESETLOGS is mandatory after incomplete recovery to reset the redo log sequence.
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The database is in mount state.
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One of the tablespaces is offline.
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One of the tablespaces is read only.
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The database operates in ARCHIEVELOG mode.
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The database operates in NOARCHIEVELOG mode.
E
Correct answer
Explanation
In NOARCHIVELOG mode, Oracle cannot perform hot/inconsistent backups because there are no archived redo logs to recover transactions. Only consistent (cold) backups are possible where the database is cleanly shut down. ARCHIVELOG mode allows both consistent and inconsistent backups.
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ODS
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Staging Area
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Data Warehouse
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Data Mart
A
Correct answer
Explanation
ODS (Operational Data Store) contains current DSS data at the lowest level of granularity in a data warehouse architecture. Staging Area is for temporary storage before integration (Option B). Data Warehouse is the integrated repository (Option C). Data Mart contains subsets for specific departments (Option D).
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Many-to-many
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One-to-one
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One-to-many
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All of the above.
C
Correct answer
Explanation
In a star schema, the relationship between a dimension table and fact table is one-to-many - one dimension record relates to many fact records (Option C). Option A (many-to-many) is incorrect because star schemas don't have direct many-to-many. Option B (one-to-one) is wrong because dimensions describe multiple facts. Option D is incorrect since the relationship is specifically one-to-many.
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Data Quality Management
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Data Transformations
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Data Mining
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Data Security Management
A
Correct answer
Explanation
Data Quality Management eliminates bad data and increases data reliability, effectiveness, and usability (Option A). Data Transformations convert data formats (Option B). Data Mining discovers patterns (Option C). Data Security Management protects data access (Option D). Only Option A directly addresses eliminating bad data.
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Integrates disparate data into meaningful information
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Collects only historical data for past data analysis
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Defines business rules
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All of the above
A
Correct answer
Explanation
Business Intelligence integrates disparate data into meaningful information (Option A is correct). Option B is wrong because BI deals with both historical and current data for predictive analysis. Option C is incorrect because business rules are defined by business processes, not BI itself. Option D is wrong since only A is true.
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Dispersed data -> Collected Data -> Integrated Data -> Information -> Knowledge
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Collected Data -> Dispersed data -> Integrated Data -> Information -> Knowledge
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Dispersed data -> Collected Data -> Integrated Data -> Knowledge-> Information
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Collected Data -> Dispersed data -> Integrated Data -> Knowledge -> Informatio
A
Correct answer
Explanation
Data flows from dispersed sources through collection and integration to become information, then knowledge (Option A correct). Option B is wrong because dispersed data precedes collection. Option C incorrectly swaps information and knowledge. Option D has both wrong order and swapped information/knowledge.
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Sourcing data from disparate sources and integrating to be central repository
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A process to change data from a detailed level to a summary level
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A process to change data from a summary level to a detailed level
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Separating data from one source into various sources of data
A
Correct answer
Explanation
Data Integration involves sourcing data from disparate sources and integrating it into a central repository (Option A correct). Option B describes aggregation/summarization, not integration. Option C describes drill-down operations. Option D describes data distribution, the opposite of integration.
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MOLAP
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ROLAP
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HOLAP
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None of the above
A
Correct answer
Explanation
MOLAP (Multidimensional OLAP) pre-computes aggregations and stores data in specialized multidimensional arrays optimized for fast query performance. This makes it ideal for small datasets with complex analytical models since the cubes fit in memory and calculations are pre-done. ROLAP is better suited for large data with simpler models, while HOLAP is a hybrid approach.
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Detailed decision making
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Operational reporting
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Drill through analysis
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All of the above
D
Correct answer
Explanation
Operational Data Store (ODS) serves as an intermediate layer between operational systems and the data warehouse. It provides current, detailed data that supports operational reporting for day-to-day business monitoring, enables drill-through from aggregated warehouse data to details, and supports tactical decision-making with near real-time data access.
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Consolidation
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Registry
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Coexistence
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Transaction
B
Correct answer
Explanation
In Master Data Management (MDM), the Registry architectural style provides a centralized reference that doesn't store the actual data but maintains indices/pointers to source systems, enabling real-time access to master data across the organization.
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Data Profiling
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Data Security
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Data Governance
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Master Data Management
B
Correct answer
Explanation
Confidentiality (protecting from unauthorized access), Integrity (preventing unauthorized modification), and Availability (ensuring authorized access when needed) form the CIA triad, which are the three fundamental goals of data security.
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ETL Tool processing engine
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Target database engine
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Source database engine
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Source and Target database engine
B
Correct answer
Explanation
ELT (Extract, Load, Transform) loads data first into the target system, then uses the target database's processing engine for transformations. This differs from ETL, which transforms before loading using a separate ETL tool.
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Shared
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Information
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Collection
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Multidimensional
D
Correct answer
Explanation
OLAP cubes are fundamentally multidimensional structures that allow analysis across multiple dimensions (time, geography, product, etc.) simultaneously, enabling complex queries and aggregations that relational databases can't efficiently handle.