The source of the data is sometimes called the system of record.
Answer: A
Correct answer: True
The system of record is the authoritative source for a piece of data - the place where it is first captured and against which any disagreement is settled. Naming it explicitly matters in an environment with copies in warehouses, marts and reports, since without it there is no way to say which copy is right.
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An enterprise data model is a relational model that shows the high-level entities for the organization and associations among those entities.
Answer: B
Correct answer: False
An enterprise data model is a graphical model, usually in entity-relationship form, showing high-level entities and their associations. Calling it relational confuses the conceptual level with the logical one: the relational model is a later stage, arrived at when the conceptual model is mapped to tables.
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Data quality problems currently cost U.S. businesses some $60 million each year (Hudica, 2003).
Answer: B
Correct answer: False
The figure usually cited is some 60 billion dollars a year, not 60 million. The order of magnitude is the point of the statistic: data quality is a problem of the scale of a national industry rather than a rounding error, which is what justifies treating it as a management programme.
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Which of the following database activities allow for the actual retrieval and use of a database?
Answer: D
Correct answer: Database implementation
Implementation is where the design becomes a working system loaded with data and reachable by applications, so it is the first stage at which anything can actually be retrieved and used. Enterprise modelling, logical design and physical design all produce specifications rather than a usable database.
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Another name for multimedia data is unstructured data.
Answer: A
Correct answer: True
Multimedia content - images, audio, video, free text - is unstructured because it has no fields the DBMS can compare or search on. It can be stored and retrieved as a whole, but locating a particular thing within it requires quite different techniques from those a query language provides.
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An advantage of the database approach is the creation of maximum data redundancy.
Answer: B
Correct answer: False
Minimum redundancy is the advantage, not maximum. Duplication is what allows copies to disagree and formats to diverge, so the database approach stores each fact once and lets applications share it. A little controlled redundancy is sometimes introduced deliberately for performance, but that is a considered exception.
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Structured data may include which of the following?
Answer: C
Correct answer: Dates
Structured data has a defined type and format that a database can operate on - numbers, dates, codes, fixed-length text. Images and video are unstructured: they can be stored, but the DBMS cannot search or compare their content in the way it can compare two dates.
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Stored representations of objects and events that have meaning and importance in the user's environment are known as a database.
Answer: B
Correct answer: False
Stored representations of objects and events that have meaning in the user’s environment are the definition of data. A database is an organised collection of logically related data, which adds the organisation and the relationships. The statement has given one definition under the other name.
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A database management system (DBMS) is a:
Answer: C
Correct answer: software system used to create, maintain, and provide controlled access to a database.
Two words carry the definition. It is software, running on ordinary hardware, and its access is controlled - who may see and change what is the DBMS’s responsibility, not the application’s. Uncontrolled access would forfeit the security and integrity that the approach exists to provide.
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Databases that contain historical and summarized information are usually called data warehouses.
Answer: A
Correct answer: True
Historical and summarised data, integrated from several operational sources and organised by subject rather than by application, is exactly what defines a warehouse. It is non-volatile from the user’s side, being loaded rather than updated, which is what makes a consistent view over time possible.
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