DATABASE FUNDAMENTALS
DATA WAREHOUSING AND DATA MINING
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Record level problem
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Value level problem
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Schema level problem
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Field level problem
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Detailed explanation-1: -Conflict resolution is often possible in customer management systems. For example, salespeople can maintain customer address information at different databases in a replication environment. Should a conflict arise, the system can resolve the conflicting updates by applying the most recent update to a record.
Detailed explanation-2: -Relationship conflicts at schema level At the schema level, relationship conflicts occur when associations in real world objects are modeled differently in the conceptual schemas of local databases.
Detailed explanation-3: -Backflow of cleaned data: After (single-source) errors are removed, the cleaned data should also replace the dirty data in the original sources in order to give legacy applications the improved data too and to avoid redoing the cleaning work for future data extractions.