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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True
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False
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Either A or B
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None of the above
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Detailed explanation-1: -The time horizon for the data warehouse is significantly longer than that of operational systems. Every key structure in the data warehouse contains an element of time (explicitly or implicitly).
Detailed explanation-2: -12. What is the time horizon in the data warehouse? Answer-C) The time horizon in the data warehouse is 5-10 years. 13.
Detailed explanation-3: -Time variance means that the data warehouse also records the timestamp of data. So inside a data warehouse, a time variant table can be structured almost exactly the same as the source table, but with the addition of a timestamp column.
Detailed explanation-4: -A data warehouse is a relational database that is designed for query and analysis rather than for transaction processing. It usually contains historical data derived from transaction data, but it can include data from other sources.
Detailed explanation-5: -Operational systems are designed to support high-volume transaction processing. Data warehousing systems are typically designed to support high-volume analytical processing (i.e., OLAP). Operational systems are usually concerned with current data. Data warehousing systems are usually concerned with historical data.