Building the Data Warehouse

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The issue is, how soon should this adjustment to the data warehouse data be made? As a rule, at least 24 hours should pass from the time the change is known to the operational environment until the change is reflected into the data warehouse (see Figure 3.41). There should be no rush to try to move the change into the data warehouse as quickly as possible. This “wrinkle of time” should be implemented for several reasons.


The first reason is that the more tightly the operational environment is coupled to the data warehouse, the more expensive and complex the technology is. A 24-hour wrinkle of time can easily be accomplished with conventional technology. A 12-hour wrinkle of time can be accomplished but at a greater cost of technology. A 6-hour wrinkle of time can be accomplished but at an even greater cost in technology.


data


warehouse



operational




J Jones 123 Main Credit — AA



J Jones 1989-1990 Apt B Credit — B



Г    


J Jones has moved


to Rte 4, Austin, TX


V_._)



J Jones 1990-1991 Apt B


Credit — AA



J Jones 1992-present 123 Main Credit — AA



Figure 3.38 What happens when the corporation finds out that J Jones has moved?



operational


Figure 3.39 The first step is to change the operational address of J Jones.


data


warehouse



J Jones 1989-1990 Apt B Credit — B



J Jones 1990-1991 Apt B


Credit — AA



( J Jones has moved to Rte 4, Austin, TX

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