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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Data Mart & DWH both are normalized and can exist in same tier
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Data Mart is normalized but DWH is not and they cannot exist in same tier.
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DWH is normalized but Data Mart is not and they can exist in same tier.
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Both Data Mart & DWH are denormalized and can exist in same tier.
D
Correct answer
Explanation
Data warehouses and data marts both use denormalized schemas to optimize query performance. Denormalization reduces joins and improves read speed, which is essential for analytical processing. Both can exist in the same tier of an architecture (e.g., an ODS feeding both a DW and multiple marts). Option D correctly states this.
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Deleting the report.
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The deletion of all the data fetched by the query.
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Deleting the report structure.
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Refreshing the report
B
Correct answer
Explanation
Report purge in BusinessObjects refers to the deletion of data retrieved by the query. When a report is purged, the data rows are removed but the report structure (layout, formatting, formulas) remains intact. This is different from deleting the entire report structure or refreshing it with new data. Option B correctly describes this.
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Sum
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Detail
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Measure
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Dimension
D
Correct answer
Explanation
In Web Intelligence multi-query documents, only Dimension objects can be merged across queries. Measures cannot be merged because they represent calculations that would conflict when combined. Detail objects are query-specific and cannot be merged. Dimensions provide the consistent reference points needed to combine data from different queries.
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You can not include complex calculations and functions in a derived table.
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Reduced maintenance of database summary tables
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Derived table provides real time data analysis
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None
B,C
Correct answer
Explanation
Derived tables reduce maintenance overhead because they eliminate the need to manually create and update physical database summary tables. They provide real-time data analysis by executing queries against current data rather than potentially stale pre-aggregated tables. Option A is incorrect because derived tables can include complex calculations and functions.
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Rows, Values, Columns
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Column, Values, Rows
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Rows, Columns, Values
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Both A and C are true
C
Correct answer
Explanation
In OLAP (Online Analytical Processing), the standard output format is a matrix where dimensions form the rows and columns, and measures (the numerical values) populate the cell values. This is the fundamental structure of a pivot table or cube view. Option A incorrectly places 'Values' in the second position, and Option B misorders the components entirely.
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Attached to Measure
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Attached to Dimension
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Standalone objects
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A & B
B
Correct answer
Explanation
Detail objects in Business Objects universe design are always attached to dimensions and provide additional descriptive information about those dimensions. They cannot exist as standalone objects (Option C) or attach to measures (Option A). This is fundamental - dimensions are the core objects, and details elaborate on them with extra context.
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Query navigation states and query results are stored in the application server memory
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If the same query has been executed by another user the result sets can be used if the OLAP cache is active
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Reading query results from OLAP cache is faster than reading from the database
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The size of the OLAP cache available does depend on the size of Cache memory available on the Users Desktop
A,B,C
Correct answer
Explanation
OLAP cache stores query navigation states and results in application server memory, enabling result sharing across users who execute the same query. Cache reads are faster than database reads since data is pre-computed and stored in memory. The cache size depends on server memory, not user desktop memory.
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Multidimensional
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Pre-calculated value
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Nested data
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Run time Calculation
B
Correct answer
Explanation
Aggregation provides OLAP with pre-calculated values, which are summary values computed in advance and stored. This enables faster query response times since calculations don't need to be performed at runtime.
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Measure Objects
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Dimension Objects
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Detail Objects
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A & B
A
Correct answer
Explanation
Metrics are derived from Measure Objects, which contain numerical values that can be aggregated (sum, average, etc.). Dimension Objects provide descriptive context for grouping, while Detail Objects provide additional attributes about dimensions.
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Multidimensionality
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Complex and adhoc query analysis
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Typically Normalized data structure with many tables
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Two dimensional data Structure with many tables
A,B
Correct answer
Explanation
OLAP achieves multidimensionality through cube structures that organize data across multiple dimensions (time, geography, product, etc.). The cube structure enables complex and ad-hoc query analysis by allowing users to navigate and slice data along any dimension combination.
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ERROR RECOVERY
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ROLLBACK
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Any one of the above
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Both of the above
D
Correct answer
Explanation
In COBOL ENVIRONMENT DIVISION, programs (not subroutines) should have both ERROR RECOVERY and ROLLBACK paragraphs. These paragraphs handle error conditions and transaction recovery. The question follows COBOL mainframe programming standards where recovery sections are required for robust program execution.
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ERROR RECOVERY
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ROLLBACK
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None of the above
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Both of the above
A
Correct answer
Explanation
In certain enterprise COBOL programming schemas, the subroutine structure requires the ERROR RECOVERY paragraph in the ENVIRONMENT DIVISION to handle execution-time anomalies and provide structured recovery blocks, distinguishing it from standard programs which do not enforce this section.
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ERROR RECOVERY
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ROLLBACK
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Any one of the above
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Both of the above
D
Correct answer
Explanation
A program (not a subroutine) in the ENVIRONMENT DIVISION should have both ERROR RECOVERY and ROLLBACK paragraphs (D). ERROR RECOVERY handles exceptional conditions, while ROLLBACK manages transaction rollback on failure. Having both ensures comprehensive error handling and data integrity. Either one alone is insufficient.
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Shiloh
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Mantis
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Yukon
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Aurum
A
Correct answer
Explanation
SQL Server 2000 was codenamed Shiloh during its development. Yukon was the codename for SQL Server 2005, Mantis was unrelated to SQL Server, and Aurum was not associated with any Microsoft SQL Server release.
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Cursor table
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Table filter
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Dynamic procedure
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View
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Summary table
D
Correct answer
Explanation
Views are virtual tables that hide underlying table structure while presenting data in a customized way. They support abstraction and can be updatable, making them ideal for allowing controlled data access without exposing base tables.