Database-Management-System
August 29, 2024Database-Management-System
August 29, 2024Database-Management-System
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Question 587
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Views are useful for _____ unwanted information, and for collecting together information from more than one relation into a single view.
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Hiding
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Deleting
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Highlighting
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All of the above
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Question 587 Explanation:
→ Views are useful for hides unwanted information, and for collecting together information from more than one relation into a single view.
→ A view is the result set of a stored query on the data, which the database users can query just as they would in a persistent database collection object.
Views advantages over tables:
→Views can represent a subset of the data contained in a table. Consequently, a view can limit the degree of exposure of the underlying tables to the outer world: a given user may have permission to query the view, while denied access to the rest of the base table.
→Views can join and simplify multiple tables into a single virtual table.
→Views can act as aggregated tables, where the database engine aggregates data (sum, average, etc.) and presents the calculated results as part of the data.
→Views can hide the complexity of data. For example, a view could appear as Sales2000 or Sales2001, transparently partitioning the actual underlying table.
→Views take very little space to store; the database contains only the definition of a view, not a copy of all the data that it presents.
→Depending on the SQL engine used, views can provide extra security.
→ A view is the result set of a stored query on the data, which the database users can query just as they would in a persistent database collection object.
Views advantages over tables:
→Views can represent a subset of the data contained in a table. Consequently, a view can limit the degree of exposure of the underlying tables to the outer world: a given user may have permission to query the view, while denied access to the rest of the base table.
→Views can join and simplify multiple tables into a single virtual table.
→Views can act as aggregated tables, where the database engine aggregates data (sum, average, etc.) and presents the calculated results as part of the data.
→Views can hide the complexity of data. For example, a view could appear as Sales2000 or Sales2001, transparently partitioning the actual underlying table.
→Views take very little space to store; the database contains only the definition of a view, not a copy of all the data that it presents.
→Depending on the SQL engine used, views can provide extra security.
Correct Answer: A
Question 587 Explanation:
→ Views are useful for hides unwanted information, and for collecting together information from more than one relation into a single view.
→ A view is the result set of a stored query on the data, which the database users can query just as they would in a persistent database collection object.
Views advantages over tables:
→Views can represent a subset of the data contained in a table. Consequently, a view can limit the degree of exposure of the underlying tables to the outer world: a given user may have permission to query the view, while denied access to the rest of the base table.
→Views can join and simplify multiple tables into a single virtual table.
→Views can act as aggregated tables, where the database engine aggregates data (sum, average, etc.) and presents the calculated results as part of the data.
→Views can hide the complexity of data. For example, a view could appear as Sales2000 or Sales2001, transparently partitioning the actual underlying table.
→Views take very little space to store; the database contains only the definition of a view, not a copy of all the data that it presents.
→Depending on the SQL engine used, views can provide extra security.
→ A view is the result set of a stored query on the data, which the database users can query just as they would in a persistent database collection object.
Views advantages over tables:
→Views can represent a subset of the data contained in a table. Consequently, a view can limit the degree of exposure of the underlying tables to the outer world: a given user may have permission to query the view, while denied access to the rest of the base table.
→Views can join and simplify multiple tables into a single virtual table.
→Views can act as aggregated tables, where the database engine aggregates data (sum, average, etc.) and presents the calculated results as part of the data.
→Views can hide the complexity of data. For example, a view could appear as Sales2000 or Sales2001, transparently partitioning the actual underlying table.
→Views take very little space to store; the database contains only the definition of a view, not a copy of all the data that it presents.
→Depending on the SQL engine used, views can provide extra security.