The document discusses the data warehouse bus architecture approach for building an enterprise data warehouse incrementally. It involves defining a standard bus interface that separate data marts can implement independently while still plugging together cohesively. During the architecture phase, a master set of standardized dimensions and facts is designed to provide uniform interpretation across the enterprise and establish the data architecture framework. The rows of the bus matrix correspond to individual data marts, which should be kept separate if their sources, processes, or implementation sizes differ significantly. Common dimensions must be consistent in meaning and attributes across different fact tables.
3.  Obviously, building the enterprise’s data
warehouse in one step is too daunting, yet
building it as isolated pieces defeats the
overriding goal of consistency.
ï‚¡ For long-term data warehouse success, we
need to use an architected, incremental
approach to build the enterprise’s warehouse.
ï‚¡ The approach we advocate is the data
warehouse bus architecture.
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4. ï‚¡ By defining a standard bus
interface for the data
warehouse environment,
separate data marts can be
implemented by different
groups at different times.
ï‚¡ The separate data marts
can be plugged together
and usefully coexist if they
adhere to the standard
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5. ï‚¡ During the limited duration architecture phase, the
team designs a master suite of standardized
dimensions and facts that have uniform
interpretation across the enterprise. This establishes
the data architecture framework
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6. ï‚¡ The rows of the bus matrix
correspond to data marts.
ï‚¡ You should create separate
matrix rows if the sources
are different, the
processes are different, or
if the matrix row
represents more than
what can reasonably be
tackled in a single
implementation iteration.
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7. ï‚¡ Common dimensions for different processes
should be the same.
 A dimension that has exactly the same meaning
and content when being referred from different
fact tables.
 Where attributes apply, they should mean the
same thing.
 Roll-up dimensions conform to the base-level
atomic dimension if they are a strict subset of that
atomic dimension. (granularity)
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9. ï‚¡ Revenue, profit, standard prices, standard
costs, measures of quality, measures of
customer satisfaction, and other key
performance indicators (KPIs) are facts that
must be conformed.
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10. ï‚¡ The Data Warehouse Toolkit.Second
Edition.The Complete Guide to Dimensional
Modeling.Ralph Kimball.Margy Ross
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