OLTP vs OLAP :
Describe the application that business is looking to build.
Business Processes :
Identify the business processes. Each of the business processes typically becomes a tables in data warehouse called FACT tables.
Fact Tables:> Granularity is at which level of detail the data will be stored for each fact table.
> Trasaction Fact : Transaction records for individual events as they happened
> Periodic Snapshot : Aggregated summary of data.
> Accumulating Snapshot :
> Additive, semi additive, non - additive Fact tables
> Factless Fact tables
Data Warehouse Bus Architecture :
> Define a standard interface for the data warehouse environment, separate data marts can be implemented by different groups at different times. The separate data marts can be plugged together and usefully coexist if they adhere to the standard.
> The team designs a master suite of standardized dimensions and facts that have uniform interpretation across the enterprise. This establishes the data architecture framework.
Data Warehouse Bus Matrix
The Data Warehouse Business Matrix is the tool of choice for documenting and communicating the Dimensional Modeling process so far. Business Processes vs Dimensions
Conformed Dimensions:
Dimension tables are not conformed if the attributes are labeled differently or contain different values. If a customer or product dimension is deployed in a nonconformed manner, then either the separate data marts cannot be used together or, worse, attempts to use them together will produce invalid results.
Flavours:
> Conformed dimensions mean the exact same thing with every possible fact table to which they are joined.
> Sometimes dimensions are needed at a rolled-up level of granularity. Perhaps the roll-up dimension is required because the fact table represents aggregated facts that are associated with aggregated dimensions
Dimensional Authority:The dimension authority has responsibility for defining, maintaining, and publishing a particular dimension or its subsets to all the data mart clients who need it.
Describe the application that business is looking to build.
Business Processes :
Identify the business processes. Each of the business processes typically becomes a tables in data warehouse called FACT tables.
Fact Tables:> Granularity is at which level of detail the data will be stored for each fact table.
> Trasaction Fact : Transaction records for individual events as they happened
> Periodic Snapshot : Aggregated summary of data.
> Accumulating Snapshot :
> Additive, semi additive, non - additive Fact tables
> Factless Fact tables
Data Warehouse Bus Architecture :
> Define a standard interface for the data warehouse environment, separate data marts can be implemented by different groups at different times. The separate data marts can be plugged together and usefully coexist if they adhere to the standard.
> The team designs a master suite of standardized dimensions and facts that have uniform interpretation across the enterprise. This establishes the data architecture framework.
Data Warehouse Bus Matrix
The Data Warehouse Business Matrix is the tool of choice for documenting and communicating the Dimensional Modeling process so far. Business Processes vs Dimensions
Conformed Dimensions:
Dimension tables are not conformed if the attributes are labeled differently or contain different values. If a customer or product dimension is deployed in a nonconformed manner, then either the separate data marts cannot be used together or, worse, attempts to use them together will produce invalid results.
Flavours:
> Conformed dimensions mean the exact same thing with every possible fact table to which they are joined.
> Sometimes dimensions are needed at a rolled-up level of granularity. Perhaps the roll-up dimension is required because the fact table represents aggregated facts that are associated with aggregated dimensions
Dimensional Authority:The dimension authority has responsibility for defining, maintaining, and publishing a particular dimension or its subsets to all the data mart clients who need it.
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