Test about database security P11
- Question 1. Value of the components of the specified key:
- Can get null values
- Cannot get null values or unknown values
- Can get null values or unknown values
- Cannot get null value but can get unknown values
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- Question 2. Key attributes are:
- Properties are not contained in the key
- Key properties
- Non-locked attributes
- Elements of the key
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- Question 3. The goal of the database is:
- Integrity of data
- Reflect honestly the real world data
- The independence of the data
- Data dependency
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- Question 4. The separation process does not cause loss of information in the sense of:
- The original relationship is restored from projection relations by natural connection magic
- The original relationship is restored correctly from projection relationships
- The original relationship is restored from projection relationships by connection magic
- The original relationship is restored from the relations projected by projection and selected
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- Question 5. φ [Ω1, Ω2 ., Ωp] is the separation - the natural connection of the relational schema if:
- Naturally connecting projection relationships
- φ [Ω1, Ω2, ., Ωp] is a separation and connection of projection relationships
- φ [Ω1, Ω2, ., Ωp] is a separation and natural connection of projection relations
- Connection of projection relations
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- Question 6. φ [Ω1, Ω2, ., Ωp] is a separation without loss of information, if:
- The result of natural connection of projection relationships containing the original relationship.
- The result of the natural connection of the main relationships is the original relationship.
- The result of natural connection of projection relationships is contained in the original relationship.
- The result of connecting relationships is shown on some properties of the original relationship.
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- Question 7. The objective of separating the relational schema is:
- To make storage easy
- In order to optimize queries
- In order to eliminate information anomalies when performing storage operations
- To perform searches
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- Question 8. It is necessary to standardize data because:
- Key value receives null value or unknown value
- When performing storage operations on non-standardized relations, information anomalies often appear
- When performing separation - connect the relationships automatically
- When performing searches, there are information anomalies
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- Question 9. Information anomaly is the cause:
- Obstructing updating and supplementing information
- Obstructing the separation of information loss
- Obstructing the search and inquiry
- Obstructing the implementation of archives
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- Question 10. The objective of data normalization is:
- Ensure data consistency
- Highest level of possibility of occurrence of information anomalies
- Ensure data security
- Guaranteed for data storage
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