Building the Data Warehouse

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To understand when a geographically or distributed business distributed data warehouse makes sense, consider some basic topologies of processing. Figure 6.1 shows a very common processing topology.


In Figure 6.1, all processing is done at the organization’s headquarters. If any processing is done at the local geographically dispersed level, it is very basic, involving, perhaps, a series of dumb terminals. In this type of topology it is very unlikely that a distributed data warehouse will be necessary.


One step up the ladder in terms of sophistication of local processing is the case where basic data and transaction capture activity occurs at the local level, as shown in Figure 6.2. In this scenario, some small amount of very basic processing occurs at the local level. Once the transactions that have occurred locally are captured, they are shipped to a central location for further processing.


site A



site C


hdqtrs ■


operational


site B


processing


Figure 6.1 A topology of processing representative of many enterprises.


site A



capture


activity



_    site C



site B



hdqtrs


operational


processing



capture


activity



capture


activity



Figure 6.2 In some cases, very basic activity is done at the site level.


Under this simple topology it is very unlikely that a distributed data warehouse is needed. From a business standpoint, no great amount of business occurs locally, and decisions made locally do not warrant a data warehouse.


Now, contrast the processing topology shown in Figure 6.3 with the previous two. In Figure 6.3, a fair amount of processing occurs at the local level. Sales are made. Money is collected. Bills are paid locally. As far as operational processing is concerned, the local sites are autonomous. Only on occasion and for certain types of processing will data and activities be sent to the central organization. A central corporate balance sheet is kept. It is for this type of organization that some form of distributed data warehouse makes sense.

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