Operational data, from which the facts are derived, is accompanied by supporting data, often referred to as reference data. The reference data relates to entities such as customers, products, sales regions, etc. Its primary purpose, within the operation processing systems, is to enable, for instance, the right products and documentation to be sent to the right addresses.
It is this data that is used to populate the dimensions and the dimensional hierarchies in the data warehouse.
In the same way that business transactions have a lifecycle, these reference entities also have a lifecycle. The lifecycle of reference data entities is somewhat different to transactions. Whereas business transactions, under normal circumstances, have a predefined lifecycle that starts at inception and proceeds through a logical path to deletion, the lifecycle of reference data can be much less clear. The existence of some entities can be discontinuous. This is particularly true of customer entities who may switch from one supplier to another and back again over time. It is also true of some other reference information, such as products (e.g., seasonal products). Also, the attributes are subject to change due to people moving, changing jobs, etc.
Operational data, from which the facts are derived, is accompanied by supporting data, often referred to as reference data. The reference data relates to entities such as customers, products, sales regions, etc. Its primary purpose, within the operation processing systems, is to enable, for instance, the right products and documentation to be sent to the right addresses.
It is this data that is used to populate the dimensions and the dimensional hierarchies in the data warehouse.
In the same way that business transactions have a lifecycle, these reference entities also have a lifecycle. The lifecycle of reference data entities is somewhat different to transactions. Whereas business transactions, under normal circumstances, have a predefined lifecycle that starts at inception and proceeds through a logical path to deletion, the lifecycle of reference data can be much less clear. The existence of some entities can be discontinuous. This is particularly true of customer entities who may switch from one supplier to another and back again over time. It is also true of some other reference information, such as products (e.g., seasonal products). Also, the attributes are subject to change due to people moving, changing jobs, etc.